New species and species reports of Croton L. (Euphorbiaceae) from the eastern forest corridor of Madagascar
Kent Kainulainen, Benjamin van Ee, Patrice Antilahimena, Hanta Razafindraibe & Paul E. Berry
Abstract
Knuai lainen, K., B. van Ee, P. antilahimena, H. RAZAFINDRAIBE & P.E.Berry (2016). New species and species reports of Croton L. (Euphorbiaceae) from the eastern forest corridor of Madagascar. Candollea 71 : 327-356. In English, English and French abstracts. DOI : http://dx.doi.org/10.15553/c2016v712a17 Six species of Croton from the Moramanga District of the Alaotra-Mangoro Region of eastern Madagascar (Toamasina Prov.) are newly described here, five of which occur in the Ambatovy mining concession. A seventh new species is described from the Ankerana Forest in the Atsinanana Region, some 80 km to the northeast of the town of Moramanga, which is one of the offset areas intended to mitigate the deforestation incurred by the Ambatovy mining project. Of the new species, Croton ferricretus Kainul., B.W. van Ee & P.E. Berry is the one most closely associated with the ultramafic soils where nickel and cobalt is being extracted. Although it is locally common, it is only known from the mine concession. Croton enigmaticus P.E. Berry & B.W. van Ee is considerably less common on the mine concession but is also known from two other sites. Croton droguetioides Kainul. & Radcl.-Sm. is known from Ambatovy and three other areas in the Alaotra-Mangoro Region, and Croton radiatus P.E. Berry & Kainul. is known only from forests on the Ambatovy mining concession and from the area of Zahamena National Park. Croton indrisilvae Kainul., B.W. van Ee & P.E. Berry is a small-leaved species known only from Analamazaotra National Park, and Croton ankeranae Kainul. is another small-leaved species known so far only from Ankerana. Croton plurispicatus P.E. Berry, Kainul. & B.W. van Ee is a distinctive small tree known mainly from the Lakato and Vohibe forests in the southern part of the Ankeniheny-Zahamena Corridor and one other location east of Analamazaotra. Croton hypochalibaeus Baill. is reinstated from synonymy and is now known from the Ambatovy area as well as in several forest remnants within the “tampoketsa” vegetation on the high central plateau of Madagascar, and in canyons of Isalo National Park. An additional species (Croton lasiopyrus Baill.) is identified from the Moramanga area for the first time, but is not currently known from Ambatovy. Amended descriptions are provided for both Croton hypochalibaeus and Croton lasiopyrus, and lectotypes are designated.
Addresses of the authors : KK, PEB : Herbarium, Department of Ecology and Evolutionary Biology, 3600 Varsity Drive, Ann Arbor, Michigan 48108, U.S.A. E-mail : [email protected] BE : Department of Biology, Universidad de Puerto Rico, Recinto Universitario de Mayagüez, Mayagüez, PR 00680, Puerto Rico, U.S.A. PA : Missouri Botanical Garden, B.P. 3391, Antananarivo 101, Madagascar. HR : Parc Botanique et Zoologique de Tsimbazaza, rue Kasanga Fernand, Antananarivo 101, Madagascar. Submitted on August 17, 2016. Accepted on October 21, 2016. First published online on November 23, 2016.
ISSN : 0373-2967 – Online ISSN : 2235-3658 – Candollea 71(2) : 327-356 (2016) © CONSERVATOIRE ET JARDIN BOTANIQUES DE GENÈVE 2016
MEP_Berry_000-000.indd 327 28.11.16 11:09 328 – The genus Croton L. (Euphorbiaceae) in the eastern forest corridor of Madagascar Candollea 71, 2016
Résumé
Knu ai laiNEN, K., B. van Ee, P. antilahimena, H. RAZAFINDRAIBE & P.E.Berry (2016). Nouvelles espèces et compte rendu des espèces du genre Croton L. (Euphorbiaceae) du corridor forestier de l’est de Madagascar. Candollea 71 : 327-356. En anglais, résumés anglais et français. DOI : http://dx.doi.org/10.15553/c2016v712a17 Six espèces de Croton L. (Euphorbiaceae) du district de Moramanga de la région Alaotra-Mangoro à Madagascar (Prov. de Toamasina) sont nouvellement décrites ici, dont cinq se trouvent dans la concession minière d’Ambatovy. Une septième nouvelle espèce est décrite de la forêt d’Ankerana dans la région Atsinanana à quelque 80 km au nord-est de la ville de Moramanga. Cette forêt est l’une des zones de compensation visant à atténuer la déforestation subie par le projet minier Ambatovy. Croton ferricretus Kainul., B.W. van Ee & P.E. Berry est parmi les nouvelles espèces celle qui est la plus étroitement associée aux sols ultramafiques d’où le nickel et le cobalt sont extraits. Bien que localement commune, elle n’est connue que de cette zone minière. Croton enigmaticus P.E. Berry & B.W. van Ee est moins commune sur cette zone, mais elle est également connue de deux autres sites. Croton droguetioides Kainul. & Radcl.-Sm. est connu d’Ambatovy et de trois autres zones de la région Alaotra-Mangoro, alors que l’espèce Croton radiatus P.E. Berry & Kainul. est connue des forêts de la concession minière d’Ambatovy et de la région du parc national de Zahamena. Croton indrisilvae Kainul., B.W. van Ee & P.E. Berry est une espèce à petites feuilles connue seulement du parc national d’Analamazaotra, tandis que Croton ankeranae Kainul., autre espèce à petites feuilles n’est connue à ce jour que de l’Ankerana. Croton plurispicatus P.E. Berry, Kainul. & B.W. van Ee est un petit arbre distinctif connu principalement des forêts Lakato et Vohibe dans la partie sud du corridor Ankeniheny-Zahamena et dans une autre localité à l’est d’Analamazaotra. Croton hypochalibaeus Baill. est rétabli comme nom accepté et est maintenant connu de la zone d’Ambatovy, ainsi que dans plusieurs vestiges de forêts des « tampoketsa », la végétation du haut plateau central de Madagascar. Il est répertorié aussi dans les canyons du parc national de l’Isalo. Une autre espèce (Croton lasiopyrus Baill.) est identifiée dans la zone de Moramanga pour la première fois, mais n’est pas connue d’Ambatovy. Des descriptions amendées sont fournies pour Croton hypochalibaeus et Croton lasiopyrus et des lectotypes sont désignés.
Keywords
Euphorbiaceae – Croton – Madagascar – Ambatovy – Ankeniheny – Zahamena Corridor – Toamasina – Ultramafic soil
MEP_Berry_000-000.indd 328 28.11.16 11:09 Candollea 71, 2016 The genus Croton (Euphorbiaceae) in the eastern forest corridor of Madagascar – 329
Introduction known as the Perinet or Andasibe forest) to the east, and the The Ambatovy mining project is the largest-ever foreign southern part of the Ankeniheny-Zahamena forest corridor investment in Madagascar, with a total project cost of US to the southeast. After making preliminary determinations $8 billion (Ambatovy, 2016). It is an open-pit operation of the herbarium specimens, we made a site visit to the on ultramafic, lateritic crust deposits in a relatively pristine Ambatovy-Analamay mining concession in March of 2016, forested area at around 1000 m elevation, located in the aiming to confirm the presence and extent of both the previ- eastern moist forests north of the town of Moramanga ously described and the new species of Croton in the area. We in the Alaotra-Mangoro Region, Toamasina Prov. The also visited both Analamazaotra and Mantadia National Parks, southern portion of the concession is known as Ambatovy, and we collected along the road from Andasibe to Lakato. while the northern part is known as Analamay. The main This paper presents the results of our work on Croton from the products of the venture are nickel, cobalt, and ammonium Ambatovy-Analamay mine and nearby areas, further confirm- sulphate, and these are transported to the processing site ing that the area harbours a diverse array of species and a on the coast near Tamatave in a slurry pipeline about number of local endemics. 220 km long. Construction on the project began in 2007, Compared to Phillipson et al. (2010), we now recog- and full production was attained in 2014, with an estimated nize 13 (vs. 15) species from the mining area itself, with life span extending for 29 years. From the beginning of the project, there has been a concerted effort to study the biotic four species newly described here (Table 1). We also provide features of the area, with the aim of mitigati ng or offsetting amended descriptions and designate lectotypes for the poorly the effects of deforestation of the mining sites. The Mis- known Croton hypochalibaeus Baill. and C. lasiopyrus Baill., souri Botanical Garden has been the main partner in efforts which were previously not recognized from this area. Lastly, to collect and document the local flora, and by 2009 their we add five more species from the adjacent areas of Andasibe, collectors had amassed over 7,700 new herbarium speci- Lakato, and the offset area of Ankerana, with three of these mens from the Ambatovy-Analamay area (Phillipson et also newly described in this article. Throughout the following al., 2010). They also tabulated that there are 1,580 higher descriptions we refer to the elements of the indumentum as plant species known from the 7,026 ha area leased by the trichomes, following Webster et al. (1966), although techni- mining company (2,126 ha in the mine footprint itself cally they may actually represent subepidermal emergences plus 4,900 ha of surrounding areas destined for conserva- (see Vitarelli et al., 2016). tion management). This number of species is a remarkable Since the Missouri Botanical Garden staff in Madagascar 14 % of the total described native vascular plant flora of is currently engaged in making Red List assessments of the Madagascar, which was tabulated at around 11,200 species Species of Concern present in the Ambatovy mining conces- (Callmander et al., 2011). Besides this high species rich- sion area, we will refrain from making our own conservation ness in a small area, Phillipson et al. (2010) estimated that assessments in this paper. 196 of the plant species were “Species of Concern”, meaning that they were known only from the mine concession and no more than three other locations. In a subsequent inter- Systematics nal report to the Ambatovy mining company after further New species inventory effort, the number of Species of Concern was reduced down to 109 (P. Phillipson, pers. comm). Croton ankeranae Kainul., spec. nova (Fig. 1C, 2). Croton L. (Euphorbiaceae) is one of the three largest woody plant genera in Madagascar, with an estimated 150 species Typus : Madagascar. Prov. Toamasina : Atsinanana there (Schatz, 2001). In their botanical inventory of the Ambatovy-Analamay mine site, Phillipson et al. (2010) Region, Distr. Brickaville, Commune Maroseranana, listed 15 species and two additional varieties of Croton (see Fokontany Ambodilendemy, Andrangato River, 18°26’37”S Table 1). Quite notably, out of these 17 taxa, at the time seven 48°46’31”E, 446 m, 13.III.2011, Antilahimena 7554 (holo- : had not been formally described, of which five were technically MICH [MICH1513200]! ; iso- : MO!, P, TAN). nomina nuda, based on an unpublished manuscript by the late Alan Radcliffe-Smith. Croton ankeranae Kainul. can be distinguished from As part of an ongoing revision of the genus Croton in the similar small-leaved shrub Croton indrisilvae Kainul., Madagascar, we have examined closely the available herbarium B.W. van Ee & P.E. Berry by its taller habit (to 12 m vs. specimens (primarily at MO, P, and TAN) from Ambatovy- <1 m) and smaller leaves (4.5-10.5 × 3.9-6.3 mm vs. 9-28 × Analamay and surrounding areas such as the Analamazaotra- 5-12 mm) that are entire (vs. crenate) with the apex acute to Mantadia national park complex (which includes the area obtuse (vs. obtuse to rounded).
MEP_Berry_000-000.indd 329 28.11.16 11:09 330 – The genus Croton (Euphorbiaceae) in the eastern forest corridor of Madagascar Candollea 71, 2016
Table 1. – Comparison of Croton L. taxa from the Ambatovy mining area between the Phillipson et al. (2010) floristic survey of the Ambatovy-Analamay mine site and the present study.
Phillipson et al. (2010) report This study Croton alceicornu Radcl.-Sm. [ined.] Included under Croton hypochalibaeus Baill. Croton droguetioides Radcl.-Sm. [ined.] Croton droguetioides Kainul. & Radcl.-Sm. Croton hovarum Leandri Incorrect determinations, one is C. macrobuxus Baill., another is C. hypochalibaeus Baill. Croton humbertii Leandri Croton humbertii Leandri Croton jennyanus Gris. ex Baill. Incorrect determinations, now Croton hypochalibaeus Baill. Croton lepidotoides Radcl.-Sm. [ined.] Croton ferricretus Kainul., B.W. van Ee & P.E. Berry Croton lichenisilvae Leandri Croton lichenisilvae Leandri Croton macrobuxus Baill. (var. uncertain) Croton macrobuxus Baill. Croton macrobuxus var. glandulifer Radcl.-Sm. [ined.] Not recognized here; it is insufficiently distinct from other populations of Croton macrobuxus Baill. Croton nitidulus Baker Croton nitidulus Baker Croton nitidulus var. cinereum Radcl.-Sm. [ined.] Not recognized here; the specimen cited as the type (in sched.) is Croton submetallicus Baill. Croton noronhae Baill. Incorrect determination, now Croton hypochalibaeus Croton sp. nov. A aff. C. nitidulus Baker We are not sure what this refers to Croton sp. nov. B aff. C. jennyanus Gris ex Baill. Croton hypochalibaeus Baill. Croton submetallicus Baill. Croton submetallicus Baill. Croton thouarsianus Baill. Incorrect determination, this may correspond to Croton lasiopyrus Baill. Croton trichotomus Geisel. Incorrect determination, now Croton macrobuxus Baill. or C. nitidulus Baker [not previously recognized in the mine area] Croton catatii Baill. [not previously recognized in the mine area] Croton enigmaticus P.E. Berry & B.W. van Ee [not previously recognized in the mine area] Croton lasiopyrus Baill. [not previously recognized in the mine area] Croton radiatus P.E. Berry & Kainul. [near mine along pipeline, possibly planted] Croton mongue Baill. [outside the mining footprint in offset area] Croton ankeranae Kainul. [outside the mining footprint, in Analamazaotra National Park] Croton indrisilvae Kainul., B.W. van Ee & P.E. Berry [outside the mining footprint, near Andasibe and on Andasibe-Lakato road] Croton plurispicatus P.E. Berry, Kainul. & B.W. van Ee [outside the mining footprint, in Mandraka area and along road to Lakato] Croton goudotii Baill. [outside the mining footprint, in Mandraka area and Mantadia National Park] Croton myriaster Baker 15 species and 2 varieties in mine area 13 species in mine area, 18 overall
MEP_Berry_000-000.indd 330 28.11.16 11:09 Candollea 71, 2016 The genus Croton (Euphorbiaceae) in the eastern forest corridor of Madagascar – 331
Shrubs to small trees 0.8-12 m tall, dichotomously branch- pubescence, small leaves with indistinct venation, and reduced ing, internodes sometimes contracted giving the appearance inflorescences. However, both the leaves and flowers of of whorled branches. Branches ± flattened on new growth and C. ankeranae are smaller and among the smallest of any densely covered by dark gray-brown fasciculate trichomes with Malagasy Croton, and the staminate flowers have only 3 to rays c. 0.2 mm long, pale gray to whitish, becoming terete 5 stamens. and glabrous with age. Stipules absent or vestigial. Leaves sub opposite, ± congested at nodes. Petioles 0.7-1.8 mm, adaxially P aratypi. – Madagascar. Prov. Toamasina : Atsinanana Region. canaliculate, sometimes with a pair of acropetiolar, stipitate Brickaville Distr., Anjahamamy, Anivoranokely, Ankerana forest, 18°24’46”S 48°49’24”E, 768 m, 28.I.2012, Antilahimena 8108 (MO, P, TAN) ; Maros- (0.2-0.4 mm long), discoid (c. 1.5 mm diam.) glands. Leaf eranana, Ambodilendemy, piste vers Vohimanana, 18°25’08”S 48°47’20”E, blades thinly coriaceous, entire, (broadly) elliptic to obovate, 1011 m, 24.III.2011, Ravelonarivo et al. 3838 (MICH, MO) ; Ambatolampy, 4.5-10.5 × 3.9-6.3 mm, apex acute-obtuse, base cuneate ; Vohimanana forest, 18°24’05”S 48°48’43”E, 927 m, 19.I.2012, Ravelona- adaxial surface glabrous, glossy, dark green when fresh and rivo & Edmond 4082 (MICH, MO, P, TAN) ; Ankerana forest, 18°25’42”S drying dark green ; secondary venation indistinct ; abaxial 48°48’38”E, 695 m, X.2005, Razakamalala et al. 2260 (MO, P, TAN). surface sparsely fasciculate, pale green when fresh and drying pale brown ; secondary venation indistinct, midrib prominent. Inflorescences comprising 1-2 staminate flowers or a solitary Croton droguetioides Kainul. & Radcl.-Sm., spec. nova pistillate flower, axillary or terminal ; bracts triangular, c. 3.0 × (Fig. 1B, 3-4). 0.2 mm. Staminate flowers with fasciculate, subglobose buds c. 0.9 mm diam., pedicels to 1.5 mm long ; sepals 5, shortly Typus : Madagascar. Prov. Toamasina : Alaotra- connate at base, lobes triangular to ovate, c. 0.7 × 0.3 mm, Mangoro Region, Moramanga Distr., Andasibe, Berano, apex acute, inflexed at anthesis, abaxially fasciculate, adaxially Ambatovy mine concession, 18°47’59”S 48°20’31”E, 1009 glabrous, margins densely ciliate, pale green ; petals 5, white, m, 22.III.2016, van Ee, Antilahimena, Kainulainen & Berry narrowly obovate to spatulate, c. 1.0 × 0.2 mm, recurved 2447 (holo- : MICH [MICH1513195]!, iso- : MO!, P!, at anthesis, abaxially sparsely papillate, adaxially glabrous, TAN!). margins densely ciliate ; disc glands/nectaries 5, opposite the sepals, sessile, ellipsoid, c. 0.1 × 0.05 mm ; stamens 3-5, Croton droguetioides Kainul. & Radcl.-Sm. is similar to white, filaments c. 1.5 mm long, ciliate, anthers broadly ellip- C. incisus Baill. but differs in its smaller leaves with serrate tic, c. 0.2 mm long ; receptacle pilose. Pistillate flowers with (vs. incised to lobed) leaf margin ; distinct abaxial venation ; fasciculate-pubescent buds c. 0.9 mm diam., pedicels 0.5- apiculate (vs. acute) apex ; and rounded to cordate (vs. cuneate) 0.9 mm long ; sepals 5, elliptic, spreading at anthesis, 1.2 × leaf base. 0.6 mm, apex rounded, abaxially stellate-pubescent, abaxially sparsely fasciculate, pale green ; disc glands/nectaries 5, opposite Shrubs or small trees, 0.8-7.0 m tall, to 6 cm diam., dichoto- the sepals, sessile, ellipsoid, c. 0.3 × 0.2 mm ; glandular filaments mously branching, internodes sometimes contracted giving (in petal position alternating with the nectary lobes) 5, linear, the appearance of whorled branches. Branches ± flattened c. 0.5 × 0.07 mm, erect ; ovary globose, c. 0.8 mm diam., densely on young growth and densely covered by villous white-gray stellate, styles 3, c. 2.5 mm long, bifurcate, spreading, recurved stellate trichomes, gray, becoming terete and glabrous with at the apices, with some fasciculate trichomes and a few pilose age. Stipules linear, 1.1-1.6 mm. Leaves alternate, ± congested trichomes at the base, white, turning brown, persistent. Capsules and whorled towards the branch tips and nodes. Petioles 3-4 × 6-7 mm, smooth, with fasciculate trichomes ; columella 3-15 mm, with a pair of stipitate glands at the junction of 2.8-3.5 mm long, cornute, capitate. Seeds not seen. the blade and the petiole, usually on the abaxial side, the stipe 0.4-1.9 mm long, the glandular portion cupular. Leaf Etymology. – The specific epithet refers to the Ankerana blades papyraceous, serrate, ovate to elliptic, 10-28 × 7-16 forest where this species is found. mm, apex apiculate, base rounded-cordate ; adaxial surface sparsely stellate-pubescent or glabrescent, glossy, dark green Distribution, Habitat and Ecology. – Croton ankeranae is to when fresh and drying matte (brownish) green ; with 3-6 pairs date only known from the Ankerana-Vohimanana montane of brochidodromus, ± penninerved secondary veins ; abaxial forest in the Antsinanana Region of Toamasina Prov., at 400- surface sparsely stellate-pubescent, mostly on the midrib ; pale 1050 m elevation (Fig. 1C). green, venation distinct and midrib prominent. Inflorescences racemose (often apically congested and umbel-like), to 20 mm Notes. – This species is probably most closely related to long, axillary or terminal, with mostly staminate flowers, some- C. indrisilvae Kainul., B.W. van Ee & P.E. Berry described times with a pistillate flower at the base ; axes densely stellate- below, which has similar whitish stems with brown-fasciculate pubescent, flattened ; bracts linear to lanceolate, 1.7-2.2 mm.
MEP_Berry_000-000.indd 331 28.11.16 11:09 332 – The genus Croton (Euphorbiaceae) in the eastern forest corridor of Madagascar Candollea 71, 2016
Fig. 1. – Distribution maps. The grey squares or white arrow on the inset maps of Madagascar show the location of the area depicted. A. Croton ferricretus Kainul., B.W. van Ee & P.E. Berry (red) ; B. Distribution of Croton droguetioides Kainul. & Radcl.-Sm. (turquoise) (Cours 4111 not shown), C. enigmaticus P.E. Berry & B.W. van Ee (light green) (Ralimanana et al. 1402 not shown), C. indrisilvae Kainul., B.W. van Ee & P.E. Berry (yellow), and C. plurispicatus P.E. Berry, Kainul. & B.W. van Ee (light purple) ; C. Croton ankeranae Kainul. (yellow), C. radiatus P.E. Berry & Kainul. (red), and Croton lasiopyrus Baill. (white). The collection in gray represents presumed hybrids between C. lasiopyrus and C. enigmaticus (van Ee et al. 2215 and 2216) ; D. Croton hypochalibaeus Baill. in Madagascar. [Google Earth Image © 2016 DigitalGlobe. Reproduced per attribution guidelines]
MEP_Berry_000-000.indd 332 28.11.16 11:09 Candollea 71, 2016 The genus Croton (Euphorbiaceae) in the eastern forest corridor of Madagascar – 333
Staminate flowers with stellate-pubescent, subglobose buds 1.0- leaves with a rounded to cordate base and distinct abaxial 1.2 mm diam., pedicels elongating from bud to anthesis, 2.0- venation. In his unpublished manuscript on Malagasy Croton, 4.2 mm long ; sepals 5, shortly connate at base, lobes broadly Alan Radcliffe-Smith had selected Cours 4111 as the type col- triangular-ovate, 0.9-1.2 × 0.8-1.0 mm, apex acute, abaxially lection for another proposed species (“C. parietarioides”), but stellate-pubescent, adaxially sparsely ciliate, margins densely we see no significant differences in it from the other specimens ciliate, pale green ; petals 5, white, narrowly obovate-spatulate, of C. droguetioides listed here. 1.4-1.7 × 0.5-0.6 mm, recurved at anthesis, abaxially papillate, adaxially ciliate, margins densely ciliate ; disc glands 5, opposite P aratypi. – Madagascar. Prov. Toamasina : Alaotra-Mangoro Region, Moramanga Distr., Ambatovy-Analamay forest, 18°48’56”S 48°18’21”E, the sepals, sessile, ellipsoid with an apical depression, c. 0.4 × 1086 m, 18.V.2011, Andriamiarinoro 211 (MO, P, TAN) ; ibid. loc., 18°47’51”S 0.3 mm, yellow ; stamens 13-16, white to pale yellow, filaments 48°20’33”E, 1036 m, 11.X.2005, Antilahimena et al. 3953 (MO, P, TAN) ; ibid. 1.3-1.8 mm long, ciliate, anthers elliptic, 0.3-0.5 mm long ; loc., 18°49’56”S 48°18’47”E, 1200 m, 12.X.2005, Antilahimena & Edmond 4017 receptacle pilose. Pistillate flowers with stellate-pubescent, (G, MO, P, TAN) ; ibid. loc., 18°51’36”S 48°17’29”E, 1059 m, 21.X.2005, Anti- subglobose buds c. 1.3 mm diam., pedicels 2.6-3.5 mm long ; lahimena & Edmond 4086 (MO, P, TAN) ; ibid. loc., 18°50’22”S 48°18’47”E, 1142 m, 24.I.2007, Antilahimena 5206 (G, MO, P, TAN) ; ibid. loc., 18°51’04”S sepals 5, elliptic, spreading at anthesis, 2.0-3.8 × 0.7-1.5 mm, 48°17’23”E, 1059 m, 9.II.2007, Antilahimena 5253 (MO, P, TAN) ; ibid. loc., apex obtuse-acute, shortly connate at base, adaxially sparsely 18°48’49”S 48°18’32”E, 1074 m, 5.III.2009, Antilahimena et al. 6998 (MO, stellate-pubescent, abaxially stellate-pubescent, glossy, pale P, TAN) ; Andasibe, Ampangalatsara, Ambodimandresy forest, 18°59’07”S green, persistent in fruit ; disc glands 5, opposite the sepals, 48°25’53”E, 966 m, 17.III.2012, Antilahimena 8228 (MICH, MO, P, TAN) ; sessile, c. 0.4 × 0.2 mm, pale yellow ; glandular filaments (in Ambatovy, 18°50’22”S 48°18’15”E, 1087 m, 17.V.2010, Bernard et al. 1571 (MO, P, TAN) ; Ambatoharanana près d’Antsevabe, [17°59’S 48°37’E], 1000 m, petal position alternating with the sepals) 5, linear, c. 1.0 × 6.III.1951, Cours 4111 (K, P, TEF) ; Ambatovy, 18°50’20”S 48°18’44”E, 1174 0.1 mm, ciliate, erect and appressed to the ovary ; ovary m, 22.IX.2008, Miandrimanana et al. 345 (MO, TAN) ; ibid. loc., 18°51’59’’S globose, c. 1.5 mm diam., stellate, styles 3, 1.5-2.8 mm long, 48°18’15”E, 916 m, 12.VIII.2008, Rabevohitra et al. 129 (TEF) ; Torotoro- each bifurcating 2-4 times, spreading, recurved at the apices, fotsy, 18°53’S 48°21’E, 950 m, 24.II.1997, Rakotomalaza et al. 1170 (MO, adaxially glabrous but with whitish pilose trichomes at the P) ; Ambatovy, 18°51’51”S 48°18’37”E, 1004 m, 10.II.2008, Rakotondrafara et al. 546 (MO, P, TAN) ; ibid. loc., 1023 m, 14.II.2008, Rakotondrafara et al. base, abaxially stellate-pubescent, white, turning brown, per- 620 (MO, P, TAN) ; Ambohibolakely, Analamay-Mantadia forest corridor, sistent. Capsules 4.2-6.2 × 5.7-6.2 mm, smooth, pale brown, Amboasary forest, 18°47’11”S 48°23’00”E, 1019 m, 25.IV.2012, Rakotovao 5809 sparsely stellate-pubescent, exocarp not separating, endocarp (MO, P, TAN) ; Ambatovy, 18°51’50”S 48°18’35”E, 980 m, 11.II.2008, Ran- woody, c. 0.2 mm thick ; columella c. 4.5 mm long, cornute. drianasolo et al. 643 (MICH, MO, P, TAN) ; ibid. loc., 18°51’51”S 48°18’48”E, Seeds not seen. 980 m, 14.II.2008, Randrianasolo et al. 677 (MO, P, TAN) ; Ambodimandresy forest, 18°59’19”S 48°25’59”E, 975 m, 16.III.2012, Razakamalala et al. 6747 (MICH, MO, P, TAN) ; Ambatovy, 18°51’58”S 48°17’33”E, 1012 m, 17.I.2005, Etymology. – The specific epithet refers to the similarity Razanatsoa et al. 76 (MICH, MO, P, TAN) ; ibid. loc., 18°47’53”S 48°20’30”E, of the leaves of this species to those of species of Droguetia 1022 m, 22.III.2016, van Ee et al. 2443 (MICH, TAN). Gaudich. (Urticaceae).
Vernacular name. – “Hazomby”. Croton enigmaticus P.E. Berry & B.W. van Ee, spec. nova (Fig. 1B, 5A-G, 6, 7I-J). Phenology. – We have seen flowering and fruiting speci- mens from January to May and from October. It is likely this Typus : Madagascar. Prov. Toamasina : Alaotra- species flowers more or less continuously throughout the year, Mangoro Region, along dirt road N of RN 2, past the although possibly less so in the drier months of the year. village of Savahoana, [Analantrongy], 984 m, 18°55’00”S 48°20’41”E, 14.VIII.2015, van Ee, Berry & Razafindraibe Distribution, habitat and ecology. – Besides the Amba 2214 (holo- : MICH [MICH1513196]! ; iso- : MICH tovy-Analamay forests, C. droguetioides is also found in the [MICH 1513197]!, MO!, P!, TAN!). Mantadia forests, in the Ambodimandresy forest (S of Route Nationale 2 near the Hotel Eulophiella), and at a more distant In its sometimes elongate, bracteate inflorescences and hispid- site north of Didy at Ambatoharanana (near Antsevabe) ; all pubescent stems, Croton enigmaticus P.E. Berry & B.W. van are in the Alaotra-Mangoro Region of Toamasina Prov., at Ee is closest to Croton bracteatus Lam. but differs in its much elevations of 975-1200 m (Fig. 1B). The species occurs in the more serrate leaf margins, larger and more conspicuous stipules, understory of evergreen montane forests. shorter petioles, and the fewer bifurcations of the stigmas. In its pubescence, leaves, and somewhat foliaceous pistillate sepals Notes. – Croton droguetioides can be readily distinguished it is also similar to C. fianarantsoae Leandri, but differs in its from other small-leaved species of Malagasy Croton by its more serrate leaves, more numerous pistillate flowers, and more stems with pale, wooly and stellate trichomes, and its serrate conspicuous stipules.
MEP_Berry_000-000.indd 333 28.11.16 11:09 334 – The genus Croton (Euphorbiaceae) in the eastern forest corridor of Madagascar Candollea 71, 2016
A A B B
C C E G 1 mm 1 mm
D D F H
Fig. 2. – Croton ankeranae Kainul. A. Flowering branch with two staminate flowers ; B. Staminate flower ; C. Pistillate flower. Note bifurcate stigmas and greenish sepals ; D. Branch with nearly mature capsule ; E. Staminate flower ; F. Staminate flower with stamens removed to show the five nectaries ; G. Pistillate flower, showing bifurcate stigmas and filamentous structure in the position of petals ; H. Pistillate flower with ovary and two sepals removed to show the five nectaries. Note the glandular filament in the petal position. [A, C-H : Antilahimena 7554 ; B : Ravelonarivo & Edmond 4082] [Photos : A, C-D : P. Antilahimena ; B : D. Ravelonarivo]
MEP_Berry_000-000.indd 334 28.11.16 11:10 Candollea 71, 2016 The genus Croton (Euphorbiaceae) in the eastern forest corridor of Madagascar – 335
Subhrubs to shrubs 0.3-2 m tall or occasionally lianescent Etymology. – The specific epithet refers to the enigmatic 3-4 m tall, often with a profusion of adventitious roots in the nature of the species, showing at times unusual characters such leaf litter layer (Fig. 6B). Stems, leaves, and inflorescence rachis as foliaceous, curved stipules, prominent bract-like pistillate densely pubescent, with stellate-lepidote trichomes having calyces, elongate inflorescences, markedly serrate leaves, and a stiff, porrect, whitish central ray 2-3 mm long, the basal mats of adventitious rootlets in the leaf litter, but other times portion of the trichomes brown to coppery. Stipules lanceolate the inflorescences are short, the stipules absent, and the leaf to falcate, often somewhat recurved, 5-10 mm × 2-4 mm, light margins are subentire. Individuals of this species can either green, foliaceous, caducous, or sometimes seemingly absent. appear to be nearly herbaceous, scraggly shrubs, or even lianas. Leaves alternate at the base of stems, but becoming more con- gested near the tips and then becoming opposite or whorled, Phenology. – From the four sets of specimens available, persistent, varying from patent to often ± drooping from the C. enigmaticus is known to flower and fruit in January, June, stems ; petioles 6-15(-20) mm long, hispid, with a pair of August, and October, so it appears to be quite aseasonal in its laterally divergent, stipitate glands at the apex, each 2-3.5 mm phenology. long, with a glandular, knobby tip. Leaf blades papyraceous- membranous, (broadly) ovate to elliptic, 5-9(-12) × 2.5-6 cm, Distribution, habitat and ecology. – Croton enigmaticus is apex acuminate, base rounded, venation brochidodromous known from just two sites in the mountains of Moramanga with 6-7 pairs of secondary veins, these ± impressed on upper Distr. in the Alaotra-Mangoro Region of Toamasina Prov. surface, margins dentate-serrate, both surfaces and margins (Fig. 1B) and from the Tsarahonenana forest near Didy, at ele- densely hispid. Inflorescences terminal, erect to drooping when vations of 950-1075 m. One of these sites is in the Ambatovy elongate, 1-8(-14) cm long (very variable from plant to plant), mine area, the second is about 15 km due south in a similarly unisexual or bisexual, with or without conspicuous light green forested region, and the Didy collection is considerably farther to brown bracts resembling the stipules ; pistillate flowers from north. In the two Moramanga Distr. sites, C. enigmaticus grows 1-10 numerous in proximal portion, staminate flowers distal in the understory or along road cuts of dense, montane ever- and in single or in few-flowered cymules of varying pedicel green forest, often together with lianescent bamboos prevalent lengths, the pedicels of both sexes usually ± divergent (perpen- in the understory. dicular) from the rachis. Staminate flowers with hispid, globose buds 2-3 mm in diam., pedicels usually variable in length on Notes. – This species is remarkable for its densely hispid same inflorescence, 1-5(-8) mm long ; sepals 5, valvate, c. 3 pubescence and variable-sized inflorescences, which can be × 1.5 mm, triangular, inflexed at anthesis ; petals 5, ligulate, very congested or quite elongate. It also has unusual folia- white, pubescent, c. 2 × 1 mm, slightly recurved at anthesis ; ceous stipules and bracts, however, these may be lacking (or stamens 15-20, white to pale yellow, filaments 2.5-3.5 mm early caducous?) on some plants. Finally, it shows extensive long, ciliate, anthers elliptic, c. 0.8 mm long. Pistillate flowers local vegetative reproduction by proliferous production of with hispid pedicels 3-8(-15) mm long ; sepals usually 5 but up adventitious roots in the litter layer. It co-occurs with plants to 7-9 on some flowers, imbricate, somewhat unequal in size, that are included here under C. lasiopyrus Baill., but they have 8-10(-15) × 3-5 mm, narrowly triangular to elliptic-lanceolate, intermediate traits that indicate they may be hybrids between acuminate, foliaceous and green on both sides, the midvein these two species. and two additional lateral veins visible, hispid on both sides and along margins, persistent in fruit ; glandular filaments (in P aratypi. – Madagascar. Prov. Toamasina : Alaotra-Mangoro petal position alternating with the sepals) 5, c. 1 mm long Region, Moramanga Distr., Andasibe, Ambatovy, Analantrongy, 18°55’13”S 48°20’26”E, 997 m, 9.VI.2009, Antilahimena et al. 7106 (MICH, MO, P, (Fig. 5G) ; ovary hispid, green, with scattered coppery-based TAN) ; ibid. loc., Antilahimena et al. 7107 (MICH, MO, P, TAN) ; Ambatovy, scales, globoid-ellipsoid, c. 3 mm diam., styles 3, each bifurcat- 18°48’11”S 48°20’49”E, 1075 m, 9.X.2007, Bernard & Phillipson 605 (MICH, ing 2-3 times near the base with a total of c. 24 stigmatic tips, MO, P, TAN) ; Ambatondrazaka Distr., Didy, Tsarahonenana forest, 4.3 km curled when young, creamy-white, turning coppery-brown, NE from Didy, 18°05’05”S 48°34’17”E, 15.I.2010, Ralimanana et al. 1402 patent. Capsules ellipsoid to subgloboid, greenish, densely (BR, G, K, MO, TAN) ; Moramanga Distr., dirt road N of Route Nationale 2 past village of Savahoana, 18°55’28”S 48°20’57”E, 972-989 m, 14.VIII.2015, hispid, c. 10 mm diam. ; columella c. 7 mm long, with a fim- van Ee et al. 2209 (MICH, MO, P, TAN) ; ibid. loc., van Ee et al. 2210 (MICH, briate tip. Seeds ± compressed-ellipsoid (Fig. 7J), c. 5.5 × 4.0 × MO, P, TAN) ; ibid. loc., van Ee et al. 2211 (MICH, MO, P, TAN) ; ibid. loc., 2.5 mm, covered by a thin, translucent-white, fleshy coating 18°55’06”S 48°20’38”E, 981 m, van Ee et al. 2212 (MICH, MO, P, TAN) ; when fresh ; testa glossy, rugulose, dark brown ; caruncle reni- ibid. loc., van Ee et al. 2213 (MICH, MO, P, TAN). form, white when fresh, c. 1.0 mm wide, 0.7 mm long.
MEP_Berry_000-000.indd 335 28.11.16 11:10 336 – The genus Croton (Euphorbiaceae) in the eastern forest corridor of Madagascar Candollea 71, 2016
A B C
D E F
Fig. 3. – Croton droguetioides Kainul. & Radcl.-Sm. A. Habit and habitat in rainforest ; B. Flowering branch with staminate flowers ; C. Underside of branch showing the stipitate glands, the sparsely stellate-pubescent leaves and the villous petioles and stem ; D. Inflorescence with staminate flowers and buds ; E. Inflorescence with pistillate flower ; F. Immature fruit. [Photos : A : K. Kainulainen ; B-F : P. Berry]
MEP_Berry_000-000.indd 336 28.11.16 11:10 Candollea 71, 2016 The genus Croton (Euphorbiaceae) in the eastern forest corridor of Madagascar – 337
Croton ferricretus Kainul., B.W. van Ee & P.E. Berry, spec. anthesis, 1.8-5.3 × 0.5-1.3 mm, apex acute, shortly connate at nova (Fig. 1A, 5H-M, 7A-B, 8). base, abaxially ferrugineous-lepidote, adaxially glabrous, pale green, persistent in fruit ; petals absent/reduced ; disc glands/ Typus : Madagascar. Prov. Toamasina : Alaotra- nectaries 5, opposite the sepals, sessile, pentagonal, 0.8-1.0 × Mangoro Region, Moramanga Distr., Andasibe, Berano, 0.6-0.8 mm, yellow ; ovary obloid, 2.0-2.5 mm diam., lepidote, Ambatovy mine concession, on “cuirasse” between the styles 3, c. 3 mm long, each bifurcating twice (or ultimately workers houses and the Ambatovy supply road, within sight thrice), spreading, recurved at the apices, abaxially ferrugine- of the Ambatovy office building, 18°51’02”S 48°18’29”E, ous-lepidote, adaxially glabrous but with yellowish pilose tri- 1142 m, 21.III.2016, van Ee, Antilahimena, Kainulainen & chomes at the base, white, turning brown, persistent. Capsules Berry 2436 (holo- MICH [MICH1513194]! ; iso- : G!, K!, 4.5-9.0 × 3.5-6.0 mm, smooth, gray-green, lepidote, exocarp MAPR!, MO!, P!, TAN!). not separating, endocarp woody, c. 0.2 mm thick ; columella 4-6 mm long, cornute, capitate. Seeds ± compressed-ellipsoid, Croton ferricretus Kainul., B.W. van Ee & P.E. Berry is c. 5 × 3 × 2 mm ; testa glossy, rugulose, punctate, dark brown ; similar to C. antanosiensis Leandri in its medium-sized, lepi- caruncle reniform c. 1.3 × 0.5 mm. dote leaves and elongate inflorescences, but differs from it in the more ferrugineous indumentum (vs. silvery), shorter petioles, Etymology. – The specific epithet refers to the ultramafic and obloid (vs. globoid) capsules. ferricrete soils to which this species is restricted.
Shrubs 0.4-4 m tall, dichotomously branching, internodes Vernacular names. – “Fotsiavadika”, “Lazalaza”. sometimes contracted giving the appearance of whorled branches. Branches ± flattened on new growth and densely Phenology. – Flowering and fruiting specimens have been ferrugineous-lepidote, brown or gray, becoming terete and collected from May through March, indicating that Croton glabrous with age. Stipules linear-triangular, 0.5-1 mm. Leaves ferricretus is quite aseasonal in its phenology. alternate along stem, subopposite or whorled at apex. Petioles 3-17(-28) mm, adaxially canaliculate, without any apparent Distribution, habitat and ecology. – Croton ferricretus is so far glands. Leaf blades subcoriaceous, entire, elliptic, 18-85 × only known from the Ambatovy-Analamay forest in Mada- 9-28 mm, apex acute to shortly acuminate (rarely obtuse), base gascar’s Moramanga Distr., occurring at 1000-1150 m altitude cuneate ; adaxial surface glabrous, glossy, dark green when fresh on ultramafic ferricrete soils (Fig. 1A, 8A). It is a common (turning orange in old leaves) and drying gray-green ; venation and sometimes dominant component of the scrublands found impressed, obscure, with 10-20 pairs of brochidodromus, ± on the most extreme rock-like crusts, and it also occurs in penninerved secondary veins ; abaxial surface densely silvery- adjacent evergreen forests with better-developed soils. When lepidote and ferrugineous-punctate, the ferrugineous scales growing on bare ferricrete (“cuirasse”), C. ferricretus does scattered among silvery ones, but more prevalent on the leaf not occur with other species of Croton, but in forested areas veins ; midrib prominent, ferrugineous-lepidote. Inflorescences it can be found growing alongside C. lichenisilvae Leandri, racemose, 20-85 mm long, axillary or terminal, with mostly C. macrobuxus Baill., C. nitidulus Baker, C. submetallicus Baill., staminate flowers, usually with 1-2(-5) pistillate flowers or C. droguetioides. at the base ; axes densely ferrugineous-lepidote, flattened ; bracts linear-lanceolate, 1-3 mm long. Staminate flowers with Notes. – Croton ferricretus was recognized in the inventory ferrugineous-lepidote, subglobose buds 1.5-2.5 mm in diam., of the Ambatovy-Analamay forest by Phillipson et al. (2010) pedicels elongating from bud to anthesis, 2-5 mm long ; sepals under the working name “Croton lepidotoides” (ined. by the 5, firm, connate about halfway from the base, lobes broadly late Radcliffe-Smith), and considered a species of concern triangular to ovate, 1.0-1.4 × 0.8-1.7 mm, apex acute, inflexed (SOC2, i.e., found only in the area of the mining footprint at anthesis, abaxially ferrugineous-lepidote, adaxially glabrous, and the surrounding conservation zone). This is a very dis- pale green ; petals 5, white, narrowly obovate-spatulate, 1.8-2.5 tinctive species among Malagasy Crotons that have small- to × 0.5-1.1 mm, recurved at anthesis, abaxially lepidote, adaxi- medium-small leaves with coppery-lepidote indumentum ally ciliate, margins densely ciliate ; disc glands/nectaries 5, (Fig. 8B-C). Other species that have these characteristics tend opposite the sepals, sessile, ellipsoid with an apical depression, to have glomerulate inflorescences in the leaf axils, such as 0.6-0.8 × 0.5-0.7 mm, yellow ; stamens 14-19, white to pale C. jennyanus Gris ex Baill. and C. hypochalibaeus Baill., rather yellow, filaments 1-2 mm long, ciliate, anthers elliptic, 0.5- than racemose inflorescences (Fig. 8D-F). It resembles 0.7 mm long ; receptacle pilose. Pistillate flowers with ferrug- C. antanosiensis Leandri from southeastern Madagascar, but ineous-lepidote, elliptic buds 2.8-3.0 × 1.7-2.5 mm, pedicels differs in its much more coppery-lepidote indumentum, 1-8 mm long ; sepals 5, firm, narrowly triangular, ascending at shorter petioles, and more obloid capsules (Fig. 7A).
MEP_Berry_000-000.indd 337 28.11.16 11:10 338 – The genus Croton (Euphorbiaceae) in the eastern forest corridor of Madagascar Candollea 71, 2016
Since this is a locally common species that is capable of gray branches with villous, whitish trichomes) ; obovate crenate growing on bare, ferricrete substrates, we believe that it may leaves with obtuse to rounded apex and cuneate base (vs. ovate be an excellent candidate for revegetation efforts once the dentate leaves with apiculate apex and rounded to cordate mining operations at Ambatovy-Analamay have ceased. Its base) ; the absence of stipitate petiolar glands ; and the lower shrubby habit would enable it to reproduce more quickly number of stigma lobes (6 vs. >30). It is sometimes confused than tree species, and it could help stabilize slopes in previ- with Croton incisus Baill. but is differentiated by its crenate ously mined areas. leaves (vs. incised to lobed) with obtuse to rounded (vs. acute) apex and the absence of stipitate petiolar glands. P aratypi. – Madagascar. Prov. Toamasina : Alaotra-Mangoro Region, Moramanga distr., Ambatovy-Analamay forest, 18°50’47”S 48°18’28”E, 1137 m, 9.II.2005, Antilahimena et al. 3323 (G, K, MO, P, TAN) ; ibid.loc., Shrubs 0.3-0.8 m tall, dichotomously branching, inter- 18°51’27”S 48°19’07”E, 1113 m, 30.IX.2005, Antilahimena & Edmond 3862 nodes sometimes contracted giving the appearance of (MICH, MO, P, TAN) ; ibid.loc., Antilahimena & Edmond 3863 (MICH, whorled branches. Branches ± flattened on new growth and MO, P, TAN) ; ibid.loc.,18°48’28”S 48°20’11”E, 1049 m, 2.XII.2005, Antila- densely covered by dark reddish-brown, fasciculate trichomes himena et al. 4324 (G, MO, P, TAN) ; ibid.loc., 18°48’29”S 48°20’21”E, 1104 with rays c. 0.5 mm long, pale gray-whitish, becoming terete m, 21.XII.2005, Antilahimena 4513 (G, K, MO, P, TAN) ; ibid.loc., 18°51’01”S 48°18’30”E, 1119 m, 6.III.2008, Antilahimena et al. 6140 (MICH, MO, P, and glabrous with age. Stipules absent or vestigial. Leaves TAN), 18°51’01”S 48°18’30”E, 1119 m, 6.V.2008, Antilahimena et al. 6144 whorled at apex and nodes. Petioles 1-3 mm long, adaxially (MICH, MO, P, TAN) ; ibid.loc., 18°51’11”S 48°19’05”E, 1095 m, 27.X.2008, canaliculate, without any apparent glands. Leaf blades thinly Antilahimena et al. 6765 (MO, TAN) ; ibid.loc., 18°51’00”S 48°18’29”E, 1114 coriaceous, slightly revolute, crenate towards apex, obovate, m, 12.XI.2009, Antilahimena & Edmond 7175 (MICH, MO, P, TAN) ; ibid. 9-28 × 5-12 mm, apex obtuse to rounded or emarginate, base loc., 18°48’34”S 48°19’08”E, 1080 m, 5.X.2007, Bernard & Phillipson 596 (MICH, MO, P, TAN) ; ibid.loc., 18°48’32”S 48°20’42”E, 11.X.2007, Bernard cuneate ; adaxial surface glabrous, glossy, dark green ; second- & Phillipson 619 (MICH, MO, P, TAN) ; ibid.loc., 18°51’14”S 48°18’56”E, ary venation indistinct, with 2-5 pairs of brochidodromus, 1114 m, 18.I.2010, Bernard et al. 1532 (MO, P, TAN) ; ibid.loc., 18°48’12”S ± penninerved secondary veins, midrib prominent except 48°21’56”E, 995 m, 3.VI.2007, Miandrimanana et al. 201 (MO, P, TAN) ; near apex ; abaxial surface sparsely covered with a mixture 22.II.1965, Peltier & Peltier 5169 (P) ; ibid.loc., Peltier & Peltier 5994 (P) ; of white and brown fasciculate trichomes, glossy, pale green 18°48’31”S 48°20’39”E, 1115 m, 6.X.2007, Phillipson et al. 6034 (MICH, MO, TAN) ; ibid.loc., 18°51’08”S 48°18’40”E, 1121 m, 30.I.1997, Rakotomalaza et when fresh and drying gray-green ; venation ± indistinct al. 1024 (MO, P, TAN) ; ibid.loc., 18°48’28”S 48°20’04”E, 1083 m, 4.IV.2005, except for the midrib. Inflorescences racemose, reduced, to Rakotovao & Edmond 1801 (MO, TAN) ; 18°48’22”S 48°20’13”E, 1075 3 mm long, terminal or axillary, bracts linear to lanceolate, m, 3.VIII.2005, Rakotovao et al. 1961 (MICH, MO, P, TAN) ; 18°48’29”S 0.5-1.0 mm. Staminate flowers with stellate-pubescent, 48°19’17”E, 1122 m, 16.I.2005, Ranaivojaona et al. 1101 (MICH, MO, P, subglobose buds c. 1.1 mm diam., pedicels c. 1.0 mm long ; TAN) ; ibid.loc., 18°50’04”S 48°17’46”E, 1107 m, 15.II.2005, Razanatsoa et al. 113 (MICH, MO, P, TAN) ; ibid.loc., 18°51’06”S 48°18’40”E, 1114 m, sepals 5, shortly connate at base, lobes triangular to ovate, 18.II.2005, Razanatsoa et al. 187 (G, MO, P, TAN) ; ibid.loc., 18°51’24”S c. 0.9 × 0.7 mm, apex acute, inflexed at anthesis, abaxially 48°19’02”E, 1114 m, 26.IX.2005, Razanatsoa et al. 401 (G, MO, P, TAN) ; stellate-pubescent, adaxially glabrous, margins ciliate ; petals 18°49’20”S 48°19’40”E, 1132 m, 20.X.2005, Razanatsoa & Razafindasy 548 5, narrowly obovate to spatulate, c. 1.2 × 0.4 mm, recurved (MO, P, TAN) ; ibid.loc., 4.III.1987, Service Forestier 31265 (TEF) ; ibid.loc., 18°48’55”S 48°19’28”E, 1114 m, 21.III.2016, van Ee et al. 2437C (MICH, at anthesis, abaxially sparsely papillate, adaxially glabrous, MO, P, TAN) ; ibid.loc., van Ee et al. 2438 (MICH, MO, P, TAN) ; ibid.loc., margins ciliate ; disc glands/nectaries 5, opposite the sepals, 18°48’28”S 48°20’11”E, 1050 m, 22.III.2016,van Ee et al. 2454 (MICH, MO, sessile, triangular, c. 0.2 × 0.1 mm ; stamens c. 5, filaments P, TAN) ; ibid.loc., van Ee et al. 2455 (MICH, MO, P, TAN). c. 1.3 mm long, ciliate, anthers broadly elliptic, c. 0.4 mm long ; receptacle pilose. Pistillate flowers with pedicels 1.5- 7.0 mm long ; sepals 5, oblong-spatulate, 2.3-3.3 × 0.7- Croton indrisilvae Kainul., B.W. van Ee & P.E. Berry, spec. 1.5 mm, apex rounded, abaxially stellate, adaxially glabrous, nova (Fig. 1B, 7G-H, 9). pale green, persistent in fruit ; disc glands/nectaries 5, oppo- site the sepals, sessile, ellipsoid with an apical depression, Typus : Madagascar. Prov. Toamasina : Alaotra- c. 0.5 × 0.3 mm, yellowish ; glandular filaments (in petal Mangoro Region, Moramanga Distr., Analamazaotra position alternating with the sepals) 5, fusiform, c. 0.4 × National Park, on trail to the east of the visitor center, 0.1 mm, reddish ; ovary globose, 1.0-1.5 mm diam., densely 18°56’45”S 48°25’33”E, 975 m, 11.VIII.2015, van Ee, Berry stellate ; styles 3, c. 1.6 mm long, bifurcating 1-2 times, & Razafindraibe 2175 (holo- : MICH [MICH1513201]! ; stellate-pubescent, persistent. Capsules 4.3-4.8 × 2.8-6.3 mm iso- : G!, MO!, TAN!). (Fig. 7G), smooth, pale brown, brown stellate-pubescent, exocarp not separating, endocarp woody, c. 0.2 mm thick ; Croton indrisilvae Kainul., B.W. van Ee & P.E. Berry is columella c. 2.5 mm long, cornute, capitate. Seeds ellipsoid distinguished from C. droguetioides Kainul. & Radcl.-Sm. (Fig. 7H), c. 3.6 × 3.0 × 2.9 mm ; testa glossy, rugulose, pale by its whitish branches with brown, fasciculate trichomes (vs. brown ; caruncle elliptic, c. 0.6 × 0.2 mm.
MEP_Berry_000-000.indd 338 28.11.16 11:10 Candollea 71, 2016 The genus Croton (Euphorbiaceae) in the eastern forest corridor of Madagascar – 339
Etymology. – The specific epithet refers to the forests where clusters of opposite or ternate leaves at the nodes, giving the this species grows, which are inhabited by the large, tail-less appearance of whorled branches. Branches terete, pale gray, the lemur species, Indri indri Gmelin, 1788. young growth densely covered by scurfy, brownish, fascicu- late to multiradiate trichomes, the longest rays 1.5-2.5 mm Distribution, habitat and ecology. – Croton indrisilvae is only long, the other rays 1.5-2 mm long, interspersed with smaller, known from Analamazaotra in the Alaotra-Mangoro Region whitish stellate-lepidote trichomes with a porrect, brownish at 900-1000 m elevation, where it forms part of the primary central radius 1-1.5 mm long. Stipules absent or 1-1.5 mm montane forest understory (Fig 1B). long and subulate. Leaves congested and ± whorled at apex and at nodes. Petioles 1-5 mm long, pubescent like the stems. Leaf Notes. – This is one of several Malagasy Croton shrubs blades papyraceous, entire, serrulate, or with shallow irregular with small leaves (< 30 mm long) from moist montane forests undulations, elliptic, 15-50 × 7-20 mm, apex and base acute ; in eastern Madagascar, including C. ambanivoulensis Baill., adaxial surface medium green and subglabrous, abaxial surface C. ankeranae, C. incisus Baill. These species all have pale stems much paler olive-green, mostly glabrous but with widely with contrasting dark fasciculate trichomes and leaves with scattered fasciculate and stellate trichomes, especially along cuneate bases and ± indistinct venation. They are mainly dis- the nerves ; venation faint, with 5-7 pairs of brochidodromus, tinguished on the basis of the shape and size of the leaves. ± penninerved secondary veins ; basilaminar glands present in Both C. ankeranae and C. indrisilvae have obovate leaves, but some leaves (but absent in over half of them), when present the leaves of C. indrisilvae are larger (< 28 × 12 mm vs. < 10.5 emerging from the abaxial side several mm from the base × 6.3 mm), somewhat revolute, and crenate (vs. entire). The of the blade, usually in pairs, sometimes single, stipitate (1.0- poorly known (and possibly conspecific) C. ambanivoulensis 2.5 mm), discoid (1.0-1.8 mm diam.), concave. Inflorescences and C. incisus have rhombic leaves that are serrate in the racemose, 8-12 mm long, axillary at leafy nodes, axis pubes- former and incised in the latter. Unlike C. indrisilvae they also cent like the stems, usually with two basal pistillate flowers have stipitate petiolar glands. and 5-10 distal staminate flowers, bracts lanceolate, pale, c. 1 mm long. Staminate flowers with subglobose buds 0.8- P aratypi. – Madagascar. Prov. Toamasina : Alaotra-Mangoro Region, 1.7 mm diam., pedicels 2.5-4 mm long ; sepals 5, lobes broadly Moramanga Distr., Station forestière d’Andasibe (Périnet), 900 m, 8.XII.1989, triangular to ovate, c. 1.4 × 1.2. mm, apex acute to rounded, Evrard 11244 (P, TAN) ; Analamazaotra, 18°56’14”S 48°25’62”E, 910 m, 20.IV.2010, Rajaovelona 258 (K, P, TAN) ; Perinet, Rauh 477 (TAN) ; Anal- abaxially with scattered whitish stellate-lepidote trichomes amazaotra, 8.III.1950, Service Forestier 715 (K, P) ; ibid loc., 8.VIII.1961, Ser- with a porrect brownish radius, adaxially glabrous, white ; vice Forestier 20317 (P) ; Analamazaotra NP, 18°56’42”S 48°25’28”E, 929 m, petals 5, white, spatulate, c. 1.5 × 0.5 mm, abaxially papil- 11.VIII.2015, van Ee et al. 2176 (MICH, MO, P, TAN). late, adaxially glabrous, margins densely ciliate ; disc glands/ nectaries 5, opposite the sepals, sessile, broadly triangular and truncate, c. 0.4 × 0.4 mm, yellowish ; stamens 8-12, white to Croton radiatus P.E. Berry & Kainul., spec. nova (Fig. 1C, 11). pale yellow, filaments c. 2.0 mm long, ciliate, anthers elliptic, c. 0.6 mm long ; receptacle pilose. Pistillate flowerswith pubes- Typus : Madagascar. Prov. Toamasina : Alaotra- cent pedicels 2-7 mm long ; sepals 5, light green, ± foliaceous Mangoro Region, Moramanga Distr., Commune Ambo- with longitudinal veins evident, oblong to spatulate, somewhat hibary, Fokontany Ampitambe, Forêt Sahaevo, 18°49’59”S unequal, apex acute to rounded, spreading at anthesis, 2-5 × 48°17’47”E, 1118 m, 11.XII.2006, Razanatsoa & Marcellin 1.5-2 mm, abaxially with a few scattered stellate trichomes, 279 (holo- : MICH [MICH1458525]! ; iso- : MO!, TAN!). adaxially glabrous ; disc glands/nectaries 5, opposite the sepals, sessile, rounded, c. 0.5 × 0.4 mm, pale yellow ; glandular fila- Croton radiatus P.E. Berry & Kainul. is similar to Croton ments 5 (in petal position alternating with sepals), c. 0.9 mm incisus Baill., but differs in its leaves that are entire to shal- long ; ovary globose, 1.5-2.0 mm diam., densely stellate, styles lowly serrulate or undulate (vs incised), and in the foliaceous, 3, 10-16 mm long, terete, ascending, each bifurcating twice glabrous sepals (vs. densely stellate-pubescent). In its tightly (yielding 4 stigmatic tips per branch, or c. 12 overall), abaxially clustered, medium-sized leaves that are separated by long inter- with a few scattered stellate trichomes ; ovary densely hirsute, nodes it resembles Croton hypochalibaeus Baill., but differs in with stiff, light brown fasciculate trichomes with radii 1.2- its sparser pubescence with scattered stellate trichomes on the 1.5 mm long. Capsules and seeds not seen. leaves (vs. densely silvery white-lepidote and brown punctulate leaves). Etymology. – The specific epithet refers to the radiate nature of the prominent trichomes, which are rather sparsely Shrubs to 0.8-2 m tall, dichotomously or trichotomously scattered on the abaxial leaf surface but much denser along branching, with elongate internodes 2-7 cm long separating the young shoots.
MEP_Berry_000-000.indd 339 28.11.16 11:10 340 – The genus Croton (Euphorbiaceae) in the eastern forest corridor of Madagascar Candollea 71, 2016
1 mm 1 mm
A B C
1 mm 1 mm
D E F
Fig. 4. – Croton droguetioides Kainul. & Radcl.-Sm. A-B. Staminate flower ; C. Staminate flower with stamens removed to show the nectaries ; D-E. Pistillate flower ; F. Pistillate flower with ovary removed to show the nectaries. Note the glandular filaments in the petal position. [A-C : van Ee et al. 2243 ; D-F : van Ee et al. 2247]
Phenology. – Of the four known specimens, one was col- According to the classification of foliar trichomes in lected in flower in December and the others in April and late Webster et al. (1996), the larger brownish trichomes of July, which indicates the species is probably aseasonal in its C. radiatus are fasciculate or multiradiate, with the radii flowering. ascending rather than in one plane, and they vary from up to 8 radii per trichome (fasciculate) to more than 8 per tri- Distribution, habitat and ecology. – Croton radiatus is known chome (radiate). The smaller, interspersed, whitish trichomes so far from four collections, in dense, humid, montane forests are stellate-lepidote with a larger, porrect, and brown central along the eastern escarpment of Madagascar in the Ankeni- radius (see Fig. 11C-D). Similar, but much shorter trichomes heny-Zahamena forest corridor in the Alaotra-Mangoro and are also characteristic of C. ankeranae and C. indrisilvae. Analanjirofo Regions of Toamasina Prov., at elevations of 900-1120 m (Fig. 1C). P aratypi. – Madagascar. Prov. Toamasina : Alaotra-Mangoro Region, Ambatondrazaka Distr., env. du Lac Alaotra (S-39), IV.1939, Cours 1257 (P) ; chutes du Maningory, Lac Alaotra (S-39), s.d., Herb. Jard. Bot. Tan. 3769 (P) ; Notes. – Croton radiatus shows a similar sylleptic growth Analanjirofo Region, Vavatenina Distr., Ambodimangavalo, Antevibe, Sahan- pattern to other species like C. hypochalibaeus, in which drazana à 3 km au NW d’Antevibe, hors du Parc National de Zahamena, long internodes separate nodes where the leaves are cluste 17°32’S 48°48’E, 900 m, 31.VII.2003, Rakotondrajaona et al. 298 (CNARP, red (Fig. 11A, 13A). This may just represent growth spurts MICH, MO, P, TEF). stimulated by periodic periods of rains following warmer, dry periods. The new species is distinctive in the ± foliaceous sepals of the pistillate flowers along with the stiffly hirsute ovary.
MEP_Berry_000-000.indd 340 28.11.16 11:10 Candollea 71, 2016 The genus Croton (Euphorbiaceae) in the eastern forest corridor of Madagascar – 341
1 mm 1 mm
A B C
2 mm 2 mm
1 mm
D E F G
1 mm 1 mm
H I J
1 mm 1 mm
K L M
Fig. 5. – Croton enigmaticus P.E. Berry & B.W. van Ee (A-G) and C. ferricretus Kainul., B.W. van Ee & P.E. Berry (H-M). A. Side view of staminate flower ; B. Top view of staminate flower ; C. Top view of staminate flower with the stamens removed to show the nectaries ; D. Side view of pistillate flower with one of the sepals removed ; E. Top view of pistillate flower with one of the sepals removed ; F. Top view of pistillate with the ovary removed to show the five nectaries ; G. Close-up of the base of a pistillate flower with the ovary and sepals removed, showing the five glandular filaments in the position of the petals (alternating with the sepals) ; H. Side view of staminate flower ; I. Top view of staminate flower ; J. Top view of staminate flower with stamens removed to show the five nectaries ; K. Side view of pistillate flower. Note basally connate sepals and parallel sides ; L. Top view of pistillate flower, showing the patent, bifurcating stigmas ; M. Top view of pistillate flower with ovary removed to show the five nectaries. [A-G : van Ee et al. 2214 ; H-M : van Ee et al. 2436]
MEP_Berry_000-000.indd 341 28.11.16 11:10 342 – The genus Croton (Euphorbiaceae) in the eastern forest corridor of Madagascar Candollea 71, 2016
Croton plurispicatus P.E. Berry, Kainul. & B.W. van Ee, spec. stamens 15-25, white to pale yellow, filaments 1.5-2 mm long, nova (Fig. 1B, 7C-D, 10, 12A-F). densely villous towards the base and on the receptacle, anthers oblong, c. 0.5 mm long. Pistillate flowers with short pedicels Typus : Madagascar. Prov. Toamasina : Alaotra- 0.5-1.5 mm long, with a narrowly lanceolate bracteole c. 0.2 Mangoro Region. Moramanga Distr., along road heading × 1.0 mm at base, sepals 5, valvate, narrowly triangular, patent S from RN 2 towards Lakato, c. 9.8 km S by line-of- at anthesis, abaxially coppery-lepidote, adaxially pale-greenish sight from RN 2, 19°03’05”S 48°21’32”E, 1030-1060 m, lepidote with coppery dots, dorsally ridged, 1.5-2.0 × 3.0- 13.VIII.2015, van Ee, Berry & Razafindraibe 2198 (holo- : 4.0 mm ; petals absent ; disc glands/nectaries 5, opposite the MICH [MICH1513198]! ; iso- : G!, MAPR!, MO!, sepals, sessile, ellipsoid, c. 0.6 × 0.4 mm, yellow ; ovary densely MICH [MICH1513199]!, P,! TAN!). coppery-lepidote, globoid, 2.5 mm diam. ; styles 3, to 3 mm long, up to five times bifurcate with numerous stigmatic tips, Croton plurispicatus P.E. Berry, Kainul. & B.W. van Ee is pale greenish-cream on upper surface, patent at anthesis. similar in pubescence and habit to Croton chrysodaphne Baill. Capsules (Fig. 7C) densely coppery-lepidote, globoid, 7- and C. submetallicus Baill., but differs in its smaller flowers 8 mm diam. ; columella 5-6 mm long, cornute, fimbriate. Seeds grouped in multiple, axillary, spicate thyrses along the distal (Fig. 7D) dark grey or brown, lenticular, 4-6 × 3-4 mm, caruncle nodes of the fertile stems. c. 0.5 × 1.0 mm, with a conspicuous raphe on ventral side below the caruncle. Shrubs or small trees to 8 m tall, to 7 cm diam. at base, densely branched with sharply ascending branches producing Etymology. – The specific epithet refers to the multiple, copious red sap when cut. Branches ± flattened on new growth, spike-like inflorescences that are clustered along the flowering ridged and furrowed, densely covered by overlapping, coppery- branches of this species. ferrugineous lepidote trichomes. Stipules absent or vestigial. Leaves alternate, ± congested towards the branch tips. Petioles Phenology. – So far, this species has been found in flower 1.0-2.5(-4.0) cm long, adaxially canaliculate. Leaf blades and fruit in February, March, May, June, and August, so it is subcoriaceous, elliptic to narrowly elliptic-oblanceolate, 3-5 likely that it flowers fairly continuously throughout the year. × 5-15 cm (to 6 × 20 cm on vigorous basal branches), apex obtuse to broadly acute or rounded, base acute to cuneate, Distribution, habitat and ecology. – Croton plurispicatus is margin entire, with a pair of prominent globoid glands 0.6- known from a relatively restricted area of primary montane 1 mm diam. at the junction of the blade and petiole, usually on moist forest from adjoining areas of the Alaotra-Mangoro and the abaxial side, the top of the gland generally with a narrow Atsinanana regions of Toamasina Prov., at elevations of 600- hollowed opening, sometimes with a second or a third pair of 1100 m (Fig. 1B). So far it has mainly been found south of similar but smaller glands on the edge of the blade shortly above Andasibe (principally along the road to Lakato), but it has also the base ; venation brochidodromous, with 9-11 pairs of second- been collected in a locality north of Route Nationale 2 near ary veins, barely noticeable on adaxial side but more visible and the southeastern corner of Mantadia National Park. Along the subprominent on abaxial side, adaxially coppery-lepidote (young Lakato road, it grows in association with the more common leaves densely coppery-lepidote, but as the leaf expands the scales and widespread C. submetallicus. become more sparse and the underlying green cuticle becomes visible), abaxially silvery-white-lepidote with ± evenly dispersed Notes. – Within Malagasy Croton, C. plurispicatus belongs brown lepidote trichomes, the midvein raised and prominent on to a diverse group of species that have in common large abaxial side, with more coppery-lepidote trichomes than rest of penninerved leaves with a dense covering of coppery- or blade. Inflorescences spicate-thyrsoid, ascending, 3-8(-9) cm long, silvery-lepidote trichomes on the underside. Leandri (1972) axillary with up to 12 in successive leaf axils on a single branch, published a note about this group in which he recognized the rachis slightly flattened or ridged, sometimes entirely seven species from Madagascar and one from the Comoro staminate or else with 1-3 basal pistillate flowers followed Islands. Berry et al. (2011) clarified the tangled history of by many cymules of staminate flowers in the distal portion. one of these, C. chrysodaphne Baill., and Berry & van Ee Staminate flowers with densely coppery-lepidote, orbicular buds (2011) established C. multicostatus Müll. Arg. as the correct c. 2 mm diam., pedicels 1-3(-4) mm long at anthesis ; sepals 5, name for another member of this group. Nonetheless, there valvate, deltate, c. 1.5 × 1.5 mm, inflexed at anthesis, abaxially are quite a few other specimens from various parts of the coppery-lepidote ; petals 5, ligulate, c. 1.2 × 1.5 mm, recurved island that fall into this morphological group that still remain at anthesis, abaxially coppery-lepidote, adaxially glabrous, unidentified, often because they lack sufficient flowering or margins densely crispate-villous ; disc glands/nectaries 5, fruiting material. opposite the sepals, sessile, ellipsoid, c. 0.8 × 0.4 mm, yellow ;
MEP_Berry_000-000.indd 342 28.11.16 11:10 Candollea 71, 2016 The genus Croton (Euphorbiaceae) in the eastern forest corridor of Madagascar – 343
A B
C D E
F G H
Fig. 6. – Croton enigmaticus P.E. Berry & B.W. van Ee. A. Climbing habit, here together with a climbing bamboo ; B. Adventitious roots emerging from the stems ; C. Typical trichotomous branching ; D. Leaves ; E. Close-up of the densely hirsute newly emergent leaves. Note the falcate stipules and stipitate acropetiolar glands ; F. Inflorescence with the pedicels of the staminate flowers perpendicular to the axis of the rachis ; G. Pistillate flower. Note the somewhat unequal, foliaceous sepals and thrice bifurcating stigmas ; H. Inflorescence showing an immature fruit, foliaceous bracts along the rachis, and staminate pedicels of varying lengths. [Photos : P. Berry]
MEP_Berry_000-000.indd 343 28.11.16 11:10 344 – The genus Croton (Euphorbiaceae) in the eastern forest corridor of Madagascar Candollea 71, 2016
We believe that the most distinctive character of this new Reinstated species taxon are the multiple narrow thyrses that appear individually in the axils of successive leaves on young branches, whereas Croton hypochalibaeus Baill. in Bull. Mens. Soc. Linn. Paris 2 : most Croton species have a single main axillary or terminal 262. 1890 (Fig. 1D, 12G-L, 13). inflorescence (Fig. 10E-F). The young stems and leaves are characterized by a very dense, coppery-lepidote indumentum Lectotypus (designated here) : Madagascar : sine that changes as the leaves expand and develop (Fig. 10E, I). On loc., s.d., Baron 5635 (K [K001040371]! ; isolecto- : P the leaf undersurface, the trichomes completely cover the blade [P00133213, P00133661]!). at maturity, but the outer fringes of the scales then become visible and are lighter in color than the coppery center of the Shrubs or trees to 5 m tall, dichotomously branching, with scales. On the upper surface, the scales are less dense and they internodes 2-14 cm long separating tight clusters of leaves at degenerate more, leaving some of the underlying green cuticle the nodes, giving the appearance of whorled branches. Branches exposed and visible when fully expanded. The basal leaf glands ± flattened on new growth and densely brown-lepidote, brown are unusual in having a narrow hollow opening on top (Fig. or gray, becoming terete and glabrous with age. Stipules awn- 10F). The stems and inflorescences are noticeably ridged and shaped, 0.9-1.5 mm. Leaves congested and ± whorled at apex partially flattened (Fig. 10D). The paucity of pistillate flowers and nodes. Petioles 1-15 mm, adaxially canaliculate, without in this species is noteworthy (only 1-3 per inflorescence when any apparent glands. Leaf blades papyraceous, entire or with present, with some inflorescences being entirely staminate) ; shallow irregular undulations, narrowly elliptic to obovate, the pistillate flowers also have very short, stout pedicels, small (7-)21-77(-145) × (5-)9-31(-45) mm, apex acute to long calyces, a lepidote inner surface, and intricate, highly divided acuminate (rarely obtuse), base attenuate to cuneate ; adaxial styles. In contrast, the staminate flowers are far more numerous surface silvery-lepidote (young leaves appear silvery), glossy, and longer-pedicellate, with numerous (15-25) stamens. (dark) green when fresh (turning orange in old leaves) and Where we collected C. plurispicatus along the road from drying matte gray-green ; venation impressed, not prominent, Andasibe to Lakato, it was most often growing in associa- with 4-11 pairs of brochidodromus, ± penninerved second- tion with the more abundant and widespread C. submetallicus. ary veins ; abaxial surface densely silvery-lepidote and brown That species is generally a lower-growing and more spreading punctulate, the brown scales ± evenly scattered among silvery shrub or tree, with the pistillate flowers having much larger white scales ; venation indistinct except for the brown-lepidote sepals and much more elongate pedicels, as well as leaves midrib. Inflorescences shortly racemose to fasciculate, 2-8(-10) with much sparser indumentum on the underside, but the mm long, axillary or terminal, with mostly staminate flowers, two do seem to intergrade and possibly hybridize in this sometimes with 1-2 pistillate flowers at the base ; axes densely area. In particular, van Ee et al. 2203 (MAPR, MICH, MO, brown-lepidote, flattened ; bracts linear to spatulate, to 6.5 × P, TAN) was a plant that had many intermediate characters 1.2 mm. Staminate flowers with brown-lepidote, subglobose between the two species. buds 1.0-1.4 mm diam., pedicels elongating from bud to anthesis, 1-4 mm long ; sepals 5, firm, shortly connate at P aratypi. – Madagascar. Prov. Toamasina : Alaotra-Mangoro Region, base, lobes broadly triangular to ovate, 1.0-1.6 × 0.9-1.5 mm, Moramanga Distr., Ambatovola, Fanovana, forêt de Vohimana, 18°55’13”S apex acute to rounded, inflexed at anthesis, abaxially brown- 48°30’49”E, Andriatsiferana et al. 2559 (MO, P, TAN) ; Lakato, VII.1973, lepidote, adaxially glabrous, white ; petals 5, white, elliptic to Guillaumet 4274 (P) ; village d’Ambodigavo, forêt d’Analanjahana à l’W spatulate, 2.0-2.9 × 0.7-1.1 mm, recurved at anthesis, abaxi- d’Ambodigavo, 19°07’39’’S 48°23’51’’E, 900 m, 31.V.2007, Razanatsima ally papillate, adaxially glabrous, margins densely ciliate ; disc et al. 290 (MO) ; Lakato, village Manasamena, forêt corridor Ankeniheny, 19°04’02’’S 48°22’02’’E, 1041 m, 19.IX.2007, Razanatsima et al. 369 (MO) ; glands/nectaries 5, opposite the sepals, sessile, triangular with Atsinanana Region, Vatomandry Distr., Ambalabe, Ambinanindrano II, le an apical depression, 0.4-0.5 × 0.3-0.5 mm, yellow ; stamens long de la piste vers SW du Tobin’I Foara, 19°10’11”S 48°34’40”E, 610 m, 10-18, white to pale yellow, filaments 1.1-3.2 mm long, ciliate, 12.III.2005, Ranaivojaona & Razanatsima 1173 (K, MICH, MO) ; ibid. loc., anthers elliptic, 0.5-0.9 mm long ; receptacle pilose. Pistillate 19°09’08’’S 48°34’47’’E, 610 m, 14.III.2005, Randrianasolo et al. 1028 (K, flowerswith brown-lepidote buds 1.5-1.8 mm diam., pedicels MICH, MO) ; Sahanionaka, forêt de Vohibe, chute Tsitondroina, 19°10’49”S 48°32’27”E, 763 m, 2.VI.2010, Razanatsima 858 (MO) ; Alaotra-Mangoro 1-3(-5) mm long ; sepals 5, firm, broadly elliptic, spreading Region, Moramanga Distr., along unpaved road from RN 2 to Lakato, at anthesis, 1.6-2.4(-5.5) × 0.9-2.2(-2.7) mm, apex acute and 19°03’35’’S 48°21’49’’E, 1015 m, 27.II.2009, van Ee et al. 981 (MAPR, inflexed, shortly connate at base, abaxially lepidote, adaxially MICH, MO, P, TAN) ; ibid. loc., van Ee et al. 982 (MAPR, MICH, MO, P, ± lepidote and ciliate towards apex, greenish white-green, TAN) ; ibid. loc., 19°04’25”S 48°22’04’’E, 906 m, 27.II.2009, van Ee et al. 984 persistent in fruit ; petals usually absent/reduced ; disc glands/ (MICH, TAN) ; ibid. loc., 19°03’05”S 48°21’32”E, 1030-1060 m, 13.VIII.2015, nectaries 5, opposite the sepals, sessile, ellipsoidal with a short van Ee et al. 2199 (MAPR, MICH, MO, P, TAN) ; ibid. loc., van Ee et al. 2200 (MAPR, MICH, MO, P, TAN) ; ibid. loc., van Ee et al. 2202 (MAPR, apex, 0.2-0.6 × 0.6-1.0 mm, pale yellow ; glandular filaments MICH, MO, P, TAN). (in petal position alternating with the nectary lobes) 5, 0.3-
MEP_Berry_000-000.indd 344 28.11.16 11:10 Candollea 71, 2016 The genus Croton (Euphorbiaceae) in the eastern forest corridor of Madagascar – 345
A 2 mm B 1 mm
C 2 mm D 1 mm
E 2 mm F 1 mm
G 2 mm H 2 mm
I 4 mm J 1 mm
Fig. 7. – Croton ferricretus Kainul., B.W. van Ee & P.E. Berry (A-B), C. plurispicatus P.E. Berry, Kainul. & B.W. van Ee (C-D), C. hypochalibaeus Baill. (E-F), C. indrisilvae Kainul., B.W. van Ee & P.E. Berry (G-H), and C. enigmaticus P.E. Berry & B.W. van Ee (I-J). A, C, E, G, I. Capsule ; B, D, F, H, J. Seed. [A-B : van Ee et al. 2436 ; C : van Ee et al. 2198 ; D : Ranaivojaona & Razanatsima 1173 ; E-F : van Ee et al. 2472 ; G-H : van Ee et al. 2176 ; I-J : van Ee et al. 2214]
MEP_Berry_000-000.indd 345 28.11.16 11:10 346 – The genus Croton (Euphorbiaceae) in the eastern forest corridor of Madagascar Candollea 71, 2016
A B
C D
E F G
Fig. 8. – Croton ferricretus Kainul., B.W. van Ee & P.E. Berry. A. Typical habitat on ultramafic crust, with C. ferricretus dominating the understory ; B. Habit ; C. Underside of branch showing the silvery-lepidote and ferrugineous-punctate leaves ; D. Inflorescence with staminate flowers and buds ; E. Inflorescence with pistillate flower and bud ; F. Infructescence with immature fruits ; G. Mature capsule. [Photos : C-D, F : P. Berry ; A-B, E, G : K. Kainulainen]
MEP_Berry_000-000.indd 346 28.11.16 11:11 Candollea 71, 2016 The genus Croton (Euphorbiaceae) in the eastern forest corridor of Madagascar – 347
0.8 mm long ; ovary subglobose, c. 2.0 mm diam., lepidote, Crotons in Madagascar that have silvery- or coppery-lepidote styles 3, 2.3-5.0 mm long, flattened, each bifurcating 3-4 leaf undersides and very condensed inflorescences. Just as with times, often with the first bifurcation congested and fused to the group of large-leaved silvery Croton species that were appear 4-furcate, spreading, recurved at the apices, abaxially first highlighted byL eandri (1972), it takes detailed field lepidote, adaxially glabrous (but appearing lepidote in some experience and careful examination of flowering and fruiting specimens where the edges of the style branches are rolled up), material to be able to successfully distinguish among the com- white, turning brown, persistent. Capsules 4.6-6.7 × c. 4.3 mm ponent species. The true C. jennyanus is restricted to northern (Fig. 7E), smooth, (pale) brown, lepidote, exocarp not separat- Antsiranana Prov. at low altitudes and shows less evidence ing, endocarp woody, c. 0.2 mm thick ; columella 3.8-5.2 mm of sylleptic branching than C. hypochalibaeus. Also, its leaves long, cornute, capitate. Seeds ± compressed-ellipsoid (Fig. 7F), have an acute to mucronate apex and a cuneate to rounded c. 4.0 × 3.0 × 2.5 mm ; testa glossy, punctate, brown ; caruncle base (vs. an acute to long-acuminate apex and attenuate to reniform c. 0.7 × 0.5 mm. cuneate base in C. hypochalibaeus), and the leaves usually dries a nitid green above (vs. a matte gray-green in C. hypochalibaeus), Etymology. – The epithet refers to the steel-colored lepidote and are ferrugineous-punctate and (silvery) glossy below (vs. indumentum on the underside of the leaves. brown-punctulate and matte [greenish- or grayish-] white in C. hypochalibaeus). Specimens that were previously identified Phenology. – Both flowering and fruiting specimens have as “Croton alceicornu Radcl.-Sm., ined.” have smaller, rounder been collected from October to April (we have not seen any leaves than typical C. hypochalibaeus specimens, but we could specimens collected between May and September), indicating find no consistent differences in floral characters between that C. hypochalibaeus is aseasonal in its phenology. them. Still, closer study in the field and examination of better reproductive material may in the future justify recognition of Distribution, habitat and ecology. – Croton hypochalibaeus is a separate taxon for this entity. mostly restricted to the eastern montane forests and the central There are some geographically outlying specimens that are highland plateau of Madagascar (“tampoketsa”) at elevations referred here with some reservation ; they are represented on of 800-1600 m, but also occurs as low as 675 m at Ankerana. the distribution map (Fig. 1D) by the four dots at the northern Most collections are from Toamasina Prov. (Ambatovy, Anda- tip of the island. Ranirison 631 from the Ampondrabe forest sibe, Ankerana, and Zahamena), but it has also been collected in Daraina (12°57’29’’S 49°41’50’’E, 580 m, 11.IV.2004, G, P) in Ambohitantely and Sohisika (Antananarivo Prov.) and as seems to be a more reduced version of this species in terms of far south as Ivohibe in Fianarantsoa Prov. and Isalo National leaf size and compact growth. However, the label alludes to the Park in Toliara Prov. Some doubtful specimens from Antsira- sylleptic branching pattern that is typical of this species, and nana Prov. are also mapped (see Fig. 1D). It typically grows in the habitat is described as a subhumid, high altitude forest. primary forest understory but it also occurs along the edges of Similar specimens collected in the Antsahabe forest near forests or in secondary woody vegetation. Daraina, are Nusbaumer 986, (13°13’02’’S 49°33’11’’E, 950 m, 15.I.2004, G, P) and Rakotondrafara et al. 358 (13°13’06’’S Vernacular names. – “Lazalaza madinidravina”, “Lazalaza 49°33’02’’E, 790 m, 1.XI.2005, MO, P). On the northwestern madinika”, “Tsiavalika”. side of the island, Harder et al. 1590, from Montagne d’Ambre (12°30’48”S 49°10’59”E, 990 m, 15.IV.1993, MO, P), is also Notes. – The two specimens of Baron 5635 at P are a close match to this species, but since it is the only collec- sparser fragments of the more complete specimen at K. Since tion we have seen from this isolated massif, we would like Leandri (1939) treated C. hypochalibaeus as a synonym of C. to see further material to confirm its presence there. Finally, noronhae, the name has not been applied to contemporary Burivalova 186, from Andrafiamena, Anjahankely, (12°54’60”S Malagasy Crotons, but the two species differ both morpho- 49°21’47”E, 726 m, 7.I.2010, G, P), may also belong here, logically and ecologically. Croton noronhae is restricted to lit- but again, it would be helpful to see additional specimens to toral, sandy-soil forests along the eastern coast of Madagascar confirm its presence in this part of Antsiranana Prov. and has dark reddish velvety shoots compared to smooth, brown-lepidote shoots in C. hypochalibaeus ; it also has evident Additional specimens examined. – Madagascar. Prov. Antananarivo : acropetiolar glands, which are lacking in C. hypochalibaeus. Analamanga Region, Ankazobe Distr., Ankazobe, Firarazana, Ankafobe for- In the Ambatovy checklist of Phillipson et al. (2010, Table est, 18°06’10”S 47°11’12”E, 1492 m, Andrianjafy 1910 (MICH, MO, P, TAN) ; 1), some of the specimens of C. hypochalibaeus listed below ibid. loc., Andrianjafy 1914 (MO, P, TAN) ; ibid. loc., XI.1955, Bosser 8596 (P) ; Mandraka, route de Tamatave, 2.XI.1972, Debray 1848 (P) ; Ankazobe, were determined either as C. jennyanus, C. noronhae, C. sp. 29.IV.1943, Decary 19358 (K, P) ; 25 km NNE Ankazobe, 18°06’S 47°11’E, nov. B aff. jennyanus, or the nom. nud. “Croton alceicornu c. 1500 m, 5.XII.1990, Gillespie 4106 (K, MO) ; Ambohitantely forest, c. 1600 Radcl.-Sm.” These all form part of a complex of small-leaved m, X.1933, Humbert 11111 (G, P) ; Manjato forest, 18°06’19”S 47°14’49”E,
MEP_Berry_000-000.indd 347 28.11.16 11:11 348 – The genus Croton (Euphorbiaceae) in the eastern forest corridor of Madagascar Candollea 71, 2016
A B
C D
E F 1 mm G 1 mm
Fig. 9. – Croton indrisilvae Kainul., B.W. van Ee & P.E. Berry. A. Habit ; B. Stem showing smooth, tan bark ; C. Branch with nearly mature capsule ; note the rounded sepals that are green and subglabrous adaxially ; D. Underside of branch showing whorled leaves ; E. Detail of nearly mature capsule ; note stiff, brown-stellate trichomes and triangular outline ; F. Staminate flower, rehydrated ; G. Pistillate flower, rehydrated . [F : van Ee et al. 2176 ; G : Service Forestier 715] [Photos : A-E : P. Berry]
MEP_Berry_000-000.indd 348 28.11.16 11:11 Candollea 71, 2016 The genus Croton (Euphorbiaceae) in the eastern forest corridor of Madagascar – 349
B
A C
D E F
G H I
Fig. 10. – Croton plurispicatus P.E. Berry, Kainul. & B.W. van Ee. A. Top of felled tree with dense ascending branches ; B. Cross-section of woody stem, showing reddish sap at cambial layer ; C. Young twig cut to show reddish latex that is exuded ; D. Twig with flattened and angled shoots ; E. Flowering branch showing the multiple thyrses along a single stem, some of them entirely staminate ; F. Inflorescence with staminate flowers and buds. Note also the basilaminar glands (lower right) ; G. Pistillate flower at anthesis showing the lepidote inner surface of the sepals and the intricately divided, patent styles ; H. Inflorescence with three basal pistillate flowers at varying stages of fruit development ; I. Inflorescence with a basal fruit and a staminate flower above it. [Photos : P. Berry].
MEP_Berry_000-000.indd 349 28.11.16 11:11 350 – The genus Croton (Euphorbiaceae) in the eastern forest corridor of Madagascar Candollea 71, 2016
13.IV.2007, Rakotoarivelo 62 (MO, P) ; Ankafobe forest, 18°06’21”S Croton lasiopyrus Baill. in Bull. Mens. Soc. Linn. Paris 2 : 926. 47°11’14”E, 1464 m, 5.IV.2013, Randrianaivo et al. 2243 (MO, P) ; ibid. loc., 1890 (Fig. 1C, 14). 18°06’11”S 47°11’10”E, 14.XII.1999, Razafindrakoto et al. 30 (K, MICH, MO, P, TAN) ; Massif de Manohilahy, Anjozorobe, 22.VIII.1952, Service Forestier 5660 (P) ; Sohisika Nature Reserve, 18°06’08”S 47°11’09”E, 1530 m, Lectotypus (designated here) : Madagascar : “Central 20.X.2009, van Ee et al. 1011 (MICH, TAN) ; below village of Andranofeno Madagascar”, X.1882, Baron 1951 (P [P00133406]! ; Sud, 18°05’02”S 47°10’49”E, 1430 m, 24.II.2016, van Ee et al. 2261 (MICH, isolecto- : K [K001040378]!, P [P00133407]!). Syntypi : MO, P, TAN). Prov. Fianarantsoa : [Ihorombe Region], Ifandana, 7.IX.1926, Madagascar : “Central Madagascar”, X.1882, Baron Decary 5246 (K, P) ; Ivohibe Distr., Réserve spéciale du Pic d’Ivohibe, Maro- vitsika forest, 22°28’49”S 46°56’49”E, 930 m, 18.X.2000, Hoffmann et al. 2114 (K [K001040377]!, P [P00133408]!) ; “Central 237 (G, K, P) ; [Amoron’i Mania Region], Faliarivo à l’W d’Ambositra, Madagascar”, s.d., Baron 4078 (K [K001040376]!) ; Fort 1600 m, 15.I.1955, Humbert & Capuron 28034 (K, P) ; [Ihorombe Region, Dauphin, s.d., Scott-Elliot 1557 (P [P00133052 packet in Ihosy Distr.] Isalo, Canyon des Singes, 15.IV.67, Jacquemin H280J (K) ; upper right]!). ibid. loc., 22°29’S 45°23’E, c. 800 m, 4.XI.1994, Lewis & McDonagh 1260 (K, MO) ; [Vatovavy-Fitovinany Region, Ifanadiana Distr.], Parc National Ranomafana, 21°15’S 47°27’E, c. 1100 m, 12.XI.1991, Malcomber et al. 1052 Shrubs 1-4 m tall. Branches with fuzzy reddish-brown indu- (MICH, MO, P). Prov. Toamasina : Alaotra-Mangoro Region, Moramanga ment. Young shoots, petioles, and inflorescence axes hirsute, with Distr., Ambatovy, 18°51’32”S 48°19’02”E, 1095 m, 30.X.2005, Antilahimena densely ferrugineous-fasciculate trichomes, with copious red sap & Edmond 3894 (G, K, MO, P, TAN) ; ibid. loc., 21.X.2005, Antilahimena & emerging when young stems are cut. Bark on older stems con- Edmond 4091 (K, MO) ; ibid. loc., 18°51’58”S 48°17’11”E, 1012 m, 26.I.2007, spicuously longitudinally striate with whitish fissures on smooth Antilahimena 5221 (MO, P, TAN) ; Sahaviana forest, 18°51’33”S 48°17’10”E, 999 m, 14.II.2007, Antilahimena 5339 (MO, P, TAN) ; Maharombotra for- grayish brown background, branching di- or trichotomous. est, 18°51’45”S 48°16’13”E, 982 m, 11.X.2008, Antilahimena et al. 6676B Stipules minute, often hidden by pubescence. Leaves alternate (MICH, MO, P, TAN) ; Ankoditrazo forest, 18°50’06”S 48°15’50”E, 954 to mostly opposite or ternate, the emerging ones usually whitish m, 24.II.2009, Antilahimena et al. 6978 (MO, P, TAN) ; ibid. loc., 18°50’11”S from the dense indument and anisophyllous (one of the pair or 48°15’51”E, 967 m, 24.II.2009, Antilahimena et al. 6981 (MICH, MO, P, trio much smaller than the others). Petioles 0.8-2.0 cm long, TAN) ; Ankosy forest, 18°49’13”S 48°16’11”E, 1031 m, 21.IV.2009, Anti- lahimena et al. 7057 (MICH, MO, P, TAN) ; Savaharina forest, 18°52’08”S with two subsessile to shortly stipitate discoid glands c. 1 mm 48°20’26”E, 1065 m, 12.XI.2009, Antilahimena & F. Edmond 7174 (MICH, diam. at the apex or just beneath the leaf blade. Leaf blades MO, P, TAN) ; Antsinanana Region, Brickaville, Anjahamamy, Anivora- (broadly) elliptic to obovate, 4-15 × 2.5-8 cm, apex rounded to nokely, Ankerana forest, 18°24’26”S 48°49’23”E, 676 m, 25.I.2012, Anti- acutely acuminate, rounded to truncate at base, margin entire or lahimena 8064 (MO, P, TAN) ; Moramanga Distr., Andasibe, Mantadia somewhat serrate in distal half, firmly chartaceous, upper surface National Park, 18°47’54”S 48°25’35”E, 961 m, 20.III.2013, Antilahimena et al. 8614, (MICH, MO, P, TAN) ; Andasibe, Analamazaotra, 18°55’31”S stellate-pubescent (densely so when young but becoming glabres- 48°25’58”E, 1025 m, 18.II.1990, Bernard et al. 1990 (MICH, MO, P, TAN) ; cent with age except for pubescent midvein), softly and densely Anony, pays Sihanaka, 3.IX.1937, Boiteau & Cours 2954 (P) ; Moramanga, pubescent on lower surface, dark green above, only slightly paler Route d’Anjiro, 900 m, XI.1938, Cours 803 (P) ; Ambatondrazaka Distr., on lower surface, brochidodromous, with 5-7 pairs of secondary Onibe, 800-1000 m, XI.1938, Cours 988 (P) ; Manambato à Amboditfonana, veins. Inflorescences shortly racemose, terminal or axillary, epedun- 1200 m, 11.X.1945, Cours 2833 (P) ; Zahamena, 22.III.1941, Decary 16708 (P) ; chutes du Maningory, XII.1944, Homolle 537 (P) ; Ambatovy, 1.VII.1966, culate, 1.0-3.5 cm long, few-flowered, bisexual or all staminate, Peltier 5997 (K, P) ; ibid. loc., 18°51’34”S 48°18’25”E, 1050 m, 3.III.1997, Rako- when bisexual with shortly-pedicellate pistillate flowers close tomalaza et al. 1220 (MO, P, TEF) ; Analamazaotra, 18°56’07”S 48°25’52”E, to the node, the pedicel 2-3 mm long, the staminate flowers 1014 m, 19.XII.2013, Ramahenina et al. 320 (MO, P, TAN) ; Ambaton- with divergent pedicels 2-6 mm long. Staminate flowers with drazaka Distr., Manakambahiny-Est, Anosivola, Zahamena, 17°43’42”S densely stellate-hirsute, globose buds ; sepals 5, lanceolate, 3.0 × 48°40’27”E, 875 m, 2.XI.2001, Randrianasolo et al. 259 (CNARP, DAV, MO, P, TEF) ; Ambatoaranana, Corridor Forestier Analamay Mantadia, 18°47’38”S 1.5 mm, abaxially stellate-pubescent ; petals 5, oblong, obtuse, 48°24’39”E, 1019 m, 23.IV.2012, Rasoazanany & Ratolojanahary 77 (MICH, 2 × 1 mm, sericeous on both surfaces and margins, white ; MO, P, TAN) ; Analamazaotra, Amboasary, 18°57’13”S 48°26’43”E, 1008 glands 5, discoid, c. 0.5 mm diam. ; stamens c. 15, filaments m, 14.II.2013, Rasoazanany et al. 324 (MICH, MO, P, TAN) ; Ambatovy, 1-2 mm long, basally pilose, anthers 0.6-0.8 mm long ; recep- 18°51’46”S 48°16’14”E, 984 m, 20.II.2010, Rasolofoniaina et al. 14 (MO, P, tacle villous. Pistillate flowers : sepals 5, lanceolate, 6.0-7.0 × TAN) ; Ambatondrazaka, Manaka Est, 2.XI.1962, Réserves Naturelles 12231 (P, TEF) ; Ambatondrazaka, Maheriara, 11.VII.1954, Service Forestier 10543 1.5-2 mm, abaxially densely stellate ; petals lacking or subulate (P) ; Ambatovy, 18°51’52”S 48°16’30”E, 1004 m, 22.III.2016, van Ee et al. 2464 and c. 1 mm long ; ovary globose, c. 5 mm diam., densely stellate- (MICH, MO, P, TAN) ; ibid. loc., van Ee et al. 2465 (MICH, MO, P, TAN) ; hirsute ; styles short, stellate-lepidote (branching pattern not ibid. loc., 18°52’08”S 48°20’26”E, 1053 m, 23.III.2016, van Ee et al. 2469 discernible with available material). Capsules depressed globose, (MICH, MO, P, TAN) ; ibid. loc., van Ee et al. 2470 (MICH, MO, P, TAN) ; densely ferrugineous-hirsute, c. 10 × 8 mm ; columella 7-8 mm ibid. loc., van Ee et al. 2471 (MICH, MO, P, TAN) ; ibid. loc., 2472 (MICH, MO, P, TAN) ; Analamazaotra, 24.X.1912, 900 m, Viguier & Humbert 989 long, cornute and fimbriate at apex. Seeds oblong-ellipsoid, c. 6.5 (P). Prov. Toliara : Anosy Region, Betroka Distr., Ivahona, Réserve Spécial de × 3.5 mm, smooth, dark brown ; caruncle c. 0.5 × 0.5 mm. Kalambatritra, forêt d’Analamaro, 23°28’14”S 46°23’38”E, 1390 m, 4.XI.2005, Andrianjafy et al. 446 (MO, P, TAN) ; ibid. loc., 23°25’12”S 46°26’45”E, Etymology. – The specific epithet alludes to the woolly fruit 1359 m, 23.V.2005, Andrianjafy et al. 1070 (K, MO, P, TAN). of this species.
MEP_Berry_000-000.indd 350 28.11.16 11:11 Candollea 71, 2016 The genus Croton (Euphorbiaceae) in the eastern forest corridor of Madagascar – 351
C A B 1 mm
C 1 mm E G
1 mm 1 mm
D 0.5 mm F H
Fig. 11. – Croton radiatus P.E. Berry & Kainul. A. Holotype specimen of Croton radiatus at MICH ; B. Inflorescence with a pair of basal pistillate flowers and five distal staminate flower buds ; C. Underside of a leaf showing both whitish stellate-lepidote trichomes and brown fasciculate to multiradiate trichomes ; D. Leaf base with a pair of stipitate, discoid glands emerging from the lamina ; E. Staminate flower (7 anthers missing) ; F. Staminate flower with stamens removed to show the nectaries ; G. Pistillate flower ; H. Top view with the ovary removed to show the five nectaries and glandular filaments. [E-F : Cours 1257 ; G-H : Razanatsoa & Marcellin 279]
MEP_Berry_000-000.indd 351 28.11.16 11:11 352 – The genus Croton (Euphorbiaceae) in the eastern forest corridor of Madagascar Candollea 71, 2016
1 mm 1 mm
A B C
1 mm 1 mm
D E F
1 mm 1 mm
G H I
1 mm 1 mm
J K L
Fig. 12. – Croton plurispicatus P.E. Berry, Kainul. & B.W. van Ee (A-F) and C. hypochalibaeus Baill. (G-L). A. Side view of staminate flower ; B. Top view of staminate flower ; C. Top view of staminate flower with stamens removed to show the five nectaries ; D. Side view of pistillate flower ; E. Top view of pistillate flower ; F. Top view of pistillate flower with ovary removed to show the five nectaries ; G. Side view of staminate flower ; H. Top view of staminate flower ; I. Top view of staminate flower with stamens removed to show the five nectaries ; J. Side view of pistillate flower ; K. Top view of pistillate flower ; L. Top view of pistillate flower with ovary removed to show the five nectaries. [A-F : van Ee et al. 2198 ; G-I : van Ee et al. 2465 ; J-L : van Ee et al. 2464]
MEP_Berry_000-000.indd 352 28.11.16 11:11 Candollea 71, 2016 The genus Croton (Euphorbiaceae) in the eastern forest corridor of Madagascar – 353
A B C
D E F
G H
Fig. 13. – Croton hypochalibaeus Baill. A. Habit ; B. Stem (diam. c. 2.5 cm) with cauliflorous flowers ; C. Close-up of the underside of a leaf ; D. Staminate flower ; E-F. Pistillate flowers ; G-H. Fruits. [Photos : P. Berry]
MEP_Berry_000-000.indd 353 28.11.16 11:11 354 – The genus Croton (Euphorbiaceae) in the eastern forest corridor of Madagascar Candollea 71, 2016
Other species records from nearby areas Phenology. – Based on the few known collections, Croton lasiopyrus does not appear to be a prolific flowerer. There are In Table 1 we list four tree species of Croton that have been remains of staminate flowers, as well as a fruit and a dehisced collected in the Ambatovy region or in similar montane forest capsule, from August, with additional flowering collections in habitats between Moramanga and Antananarivo. Croton catatii April, August, November, and December. Baill. (van Ee et al. 971, 2223, and 2431, MICH, MO, P, TAN) and C. goudotii Baill. (van Ee et al. 970 and 2225, MICH, MO, Distribution, habitat and ecology. – Croton lasiopyrus grows P, TAN) are both found near Mandraka in Antananarivo in ravines and the understory of montane moist forests on the Prov., but C. goudotii has also been found along the road from eastern side of Madagascar, in Antananarivo and Toamasina Andasibe to Lakato near the village of Ambodiriana (van Prov., at altitudes of 900-1200 m. (Fig. 1C). Ee et al. 972 and 973, MICH, MO, P, TAN). Croton catatii is now known from Ambatovy as well (Antilahimena et al. Notes. – Key distinguishing characters of C. lasiopyrus 7116, MO, P, TAN). Croton mongue Baill. is also found above include the rusty, woolly pubescence on the stems and leaves, Ambodiriana (van Ee et al. 974, 975 and 2205, MICH, MO, the short-petiolate, elliptic to ovate, acuminate-tipped leaves, P, TAN) and appears to hybridize in that area with C. goudotii. the new leaves tightly clustered at a node and often anisophyl- It also occurs in the Ambodimandresy forest near the Hotel lous (of different sizes in the same pair or cluster), and the Eulophiella (van Ee et al. 2221, MICH, MO, P, TAN). In 2016 short inflorescences that appear axillary in the leaf clusters we collected C. mongue along the pipeline and road descend- (Fig. 14). The syntype Scott-Elliot 1557 is not this species at all, ing from Ambatovy towards the coast just east of the mine but rather C. cassinoides Lam., from the Fort Dauphin area of (van Ee et al. 2468, MICH, MO, P, TAN), but it may actually Toliara Prov. There is another Scott-Elliot specimen from Fort have been planted there some years ago as part of reforestation Dauphin that is close to, but probably not conspecific with, efforts (Antilahimena, pers. obs.). Croton myriaster Baker was C. lasiopyrus, namely Scott-Elliot 2699 (K, P), so there may also found in the Mandraka area along the railroad tracks at have been a mix-up in the numbers cited by Baillon (1890). PK 68 (van Ee et al. 2432, MICH, MO, P, TAN), as well as in Two collections (van Ee et al. 2215 and 2216) from the Mantadia National Park along the road from Andasibe (van forest north of Route Nationale 2 between Andasibe and Ee et al. 2187, MICH, MO, P, TAN). Ambatovy share many characters with C. lasiopyrus (18°54’57”S 48°20’43”E, 978 m, 14.VIII.2015, MICH, MO, P, TAN), but Acknowledgements they were growing in close proximity to denser populations of C. enigmaticus, and we suspect they may be the result of intro- This paper is based on work supported by the National Science gression with that species. This is evidenced by noticeably serrate Foundation under Grants DEB-1353162 and DEB-1353070. and acuminate-tipped leaves, more stipitate petiolar glands, and We are very grateful to the staff of the Missouri Botanical somewhat larger inflorescences and longer pistillate pedicels. Garden office in Madagascar and the Parc Botanique et Zoologique de Tsimbazaza in Antananarivo for their assis- Additional specimens examined. – Madagascar. Prov. Antananarivo : tance with permits and field work. Specimens were collected Analamanga Region. La Mandraka, 7.II.1937, Herb. Jard. Bot. Tan. 2380 in Madagascar under research permits numbers 156/15 and (P) ; ibid. loc., 7.XII.1959, Schlieben 8140 (G, K) ; ibid. loc., 8.X.1961, Service Forestier 20332 (G, K, MO, P). Prov. Toamasina : Alaotra-Mangoro Region, 30/16 from the Madagascar Secrétariat Général, Direction [Ambatondrazaka Distr.], forêt d’Ambodipaiso, près d’Antsevabe, 1200 m, Générale des Forêts, Direction des Aires Protegées Terrestres 12.I.1945, Cours 2293 (K, MO, P) ; Anony, forêt du N aux confins du pays (MEEMF/SG/DGF/DAPT/SCBT). We are most grateful Sihanaka, [17°13’S 48°32’E], 3.IX.1937, Herb. Jard. Bot. Tan. 2957 (P) ; Mora- to the staff of the Ambatovy mining operations for hosting manga Distr., Ambohibolakely, Corridor Forestier Analamay Mantadia, forêt our visit to the mine sites and surrounding areas during our d’Amboasary, 1019 m, 25.IV.2012, 18°47’11”S 48°23’00”E, Rakotovao 5812 (MO, P, TAN) ; Lakato, forest E of Manasamena village, along the Ankan- visit there in March of 2016. We are grateful to Madagascar drabe trail, 1062-1100 m, 2.VI.2007, Randrianasolo et al. 1148 (MO, P, TAN) ; National Parks for permission to collect in Andasibe-Man- along road to Lakato, 1080 m, 19°03’10”S 48°22’20”E, 11.XI.2003, Schatz tadia National Park. We also thank the curators of MICH, et al. 4186 (MO, P) ; ibid. loc., 1022 m, 19°02’47”S 48°21’25”E, 27.II.2009, MO, P, TAN, and TEF for allowing access to their collections. van Ee et al. 978 (MICH, MO, P, TAN) ; ibid. loc., 1022-1038 m, 19°02’52”S Pete Phillipson and Martin Callmander both provided very 48°21’24”E, 13.VIII.2015, van Ee et al. 2197 (MICH, MO, P, TAN) ; ibid. loc., van Ee et al. 2204 (MICH, MO, P, TAN). useful comments to improve an earlier version of the manu- script. Lastly, we wish to acknowledge the significant work on Malagasy Croton by the late Alan Radcliffe-Smith of the Royal Botanic Garden, Kew, who recognized some of the new taxa described here in an unpublished manuscript.
MEP_Berry_000-000.indd 354 28.11.16 11:11 Candollea 71, 2016 The genus Croton (Euphorbiaceae) in the eastern forest corridor of Madagascar – 355
B
A C
D E F
G H I
Fig. 14. – Croton lasiopyrus Baill. A. Habit, with patent leaves ; B. Cross-section of woody stem (diam. c. 4 cm), showing reddish sap at cambial layer ; C. Young twig cut to show the reddish sap that is exuded ; D. Leaves. Note the atypical serrate leaf margin of this specimen (van Ee et al. 2215), which may be introgressed with C. enigmaticus ; E. Shoot apex with anisophyllous leaves ; F. Close up of shoot showing the reddish, wooly pubescence. Note the acropetiolar gland at the lower side of the blade ; G. Inflorescence with old staminate flowers and bud. Note the divergent pedicels ; H. Pistillate flower ; I. A nearly mature capsule and the remaining calyx and columella of an already dehisced capsule. [A, C-E, G, I : van Ee et al. 2197 ; B, F : van Ee et al. 978 ; H : van Ee et al. 2215] [Photos : A, C-E, G-I : P. Berry ; B, F : B. van Ee]
MEP_Berry_000-000.indd 355 28.11.16 11:12 356 – The genus Croton (Euphorbiaceae) in the eastern forest corridor of Madagascar Candollea 71, 2016
References Leandri, J. (1972). Contribution à l’étude des Croton malgaches a Ambatovy (2016). Ambatovy.com [http://www.ambatovy.com/ grandes feuilles argentées. Adansonia ser. 2, 12 : 403-408. docs/?p=110]. Madagascar Catalogue (2013). Catalogue of the Vascular Plants of Baillon, H. (1891). Croton lasiopyrus Baillon, in ‘Liste des plantes Madagascar. Missouri Botanical Garden, St. Louis & Antanana- de Madagascar’. Bull. Mens. Soc. Linn. Paris. 2 : 926. rivo [http://www.efloras.org/madagascar]. Berry, P. E., B. van Ee & E.A. Haber (2011). Resolving the tan- Phillipson, P.B., P.P. Lowry II, L. Andriamahefarivo, P. Anti- gled identity of Croton chrysodaphne Baill. (Euphorbiaceae) lahimena & C. Birkinshaw (2010). Floristic inventory of the in Madagascar. Candollea 66 : 113-118. DOI : http://dx.doi. Ambatovy-Analamay mine site and comparison to other sites in org/10.15553/c2011v661a10 Madagascar. Malagasy Nat. 3 : 44-76. Berry, P.E. & B. van Ee (2011). Recognition of Croton multicosta- Schatz, G.E. (2001). Generic tree flora of Madagascar. Royal Botanic tus Müll. Arg. (Euphorbiaceae) as native to Madagascar. Candol- Gardens, Kew & Missouri Botanical Garden, St. Louis. lea 66 : 109-112. DOI : http://dx.doi.org/10.15553/c2011v661a9 Vitarelli, N.C., R. Riina, M.F. Cassino & R.M.S.A. Meira Berry, P.E., B. van Ee, K. Kainulainen & H. Razafindraibe (2016). Trichome-like emergences in Croton of Brazilian high- (2016). Croton aleuritoides P.E. Berry (Euphorbiaceae), a dis- land rock outcrops : Evidences for atmospheric water uptake. tinctive new tree species from Montagne des Français in north- Perspect. Pl. Ecol. Evol. Syst. 22 : 23-35. ern Madagascar. Candollea 71 : 181-188. DOI : http://dx.doi. Webster, G.L., M.J. Del-Arco-Aguilar & B.A. Smith (1966). org/10.15553/c2016v712a3 Systematic distribution of foliar trichome types in Croton Callmander, M.W., P.B. Phillipson, G.E. Schatz, S. Andriamb- (Euphorbiaceae). Bot. J. Linn. Soc. 121 : 41-57. ololonera, M. Rabarimanarivo, N. Rakotonirina, J. Raha- rimampionona, C. Chatelain, L. Gautier & P. P. L ow ry II (2011). The endemic and non-endemic vascular flora of Mada- gascar updated. Pl. Ecol. Evol. 144 : 121-125. DOI : https://doi. org/10.5091/plecevo.2011.513
MEP_Berry_000-000.indd 356 28.11.16 11:12