New Species of Malleastrum (Meliaceae) from

Vanessa P´erez Botany and Plant Sciences Department, University of California, Riverside, California 92521, U.S.A.

James S. Miller Missouri Botanical Garden, 4434 Shaw Blvd., St. Louis, Missouri 63110, U.S.A. [email protected]

ABSTRACT. Three new species of Malleastrum (Baill.) 1. Malleastrum acuminatum V. P´erez& J. S. Mill., J.-F. Leroy are described from Madagascar and compared sp. nov. TYPE: Madagascar. Analanjirofo [Toama- to the most similar of the 22 other accepted species in sina]: , trail E of village of Hiaraka, the genus. Malleastrum acuminatum V. P´erez & J. S. toward the rock, ESE of Maroansetra, across bay, Mill., M. longifoliolatum V. P´erez & J. S. Mill., and M. on NW coast of Masoala Peninsula, dense, undis- obovatum V. P´erez & J. S. Mill. are described, differences turbed forest, 15°309S, 49°569E, 425 m, 9 Oct. from the most similar species are presented, and their 1986, P. P. Lowry II, A. Rakotozafy & M. Nicoll conservation status is discussed. 4046 (holotype, MO!). Figure 1. Key words: Madagascar, Malleastrum, Meliaceae. Diagnosis. Malleastrum acuminatum V. P´erez& J. S. Mill. is distinguished from M. mocquerysi (Aug. DC.) J.-F. Leroy in Malleastrum (Baill.) J.-F. Leroy (Meliaceae) is a ge- having elliptic-ovate to elliptic or oblong, chartaceous leaf- nus of 22 species endemic to the southwest Indian lets (vs. oblong, coriaceous leaflets), with apices prolonged- Ocean in the broadly defined Madagascar region (Leroy acuminate with a 3–9 mm acumen (vs. apices variable, usually & Lescot, 1996). Twenty species are endemic to Mada- acute to abruptly short-acuminate), that dry bright yellow (vs. gascar: M. depauperatum (Baill.) J.-F. Leroy is endemic dark green). to the Comores, and M. leroyi Fosberg occurs only on Shrub or small tree to 4 m tall; twigs light brown with Aldabra in the Seychelles (Fosberg, 1974). The genus faint brown lenticels. Leaves compound, imparipinnate, was segregated from the now monospecific genus with 5 to 11 leaflets; leaflets chartaceous, drying bright Cipadessa Blume, which occurs in southeast Asia (Leroy, yellow, elliptic-ovate to elliptic or oblong, 78–123 3 1960). Since the most recent publications of new spe- 33–41 mm, apex acuminate, acumen often hooked at cies described by Cheek (1990) and in Leroy and Lescot end, 3–9 mm, base cuneate, sometimes inequilaterally (1996), many new collections have been made and a so; margins entire; venation brochidodromous, midrib, significant percentage appear to represent undescribed secondary and tertiary veins prominent on adaxial and species. Many collections that appear to represent abaxial surfaces; petiole 40–50 mm, indistinctly winged, undescribed species are inadequate for description, wing up to 0.5–1 mm thick. Inflorescences sessile, ax- but three are reasonably well documented and are illary panicles; rachis 13–15 3 0.5–1 mm, ebracteate; morphologically distinct in the genus, and these are pedicels articulate with peduncle, 2–3 3 ca. 0.5 mm. described below. Preliminary assessments of conserva- Flower buds before anthesis easily detached; calyx green, tion status following IUCN (2012) criteria are given for campanulate, ca. 1–2 mm, 5-lobed, lobes 1 3 ca. 1 mm; each new species. petals white on both surfaces; mature flowers unknown. In addition to the species described here, there are Immature fruit a berry, pale green, slightly rounded- also six likely new species among the unidentified triangular. specimens of Malleastrum at MO for which material Distribution and habitat. Malleastrum acuminatum is is not adequate to allow description until more material known from only four collections all made in the same is collected, especially fertile material. Working toward region on the west coast of the Masoala Peninsula east- a comprehensive classification of the Malleastrum spe- southeast of Maroantsetra. The reported habitat is dense, cies from Madagascar is an essential step toward under- undisturbed primary forest. standing the conservation status of each species and also their possible uses, as exemplified by one of the IUCN Red List category. According to IUCN Red newly described species, M. obovatum V. P´erez& J. S. List criteria, Malleastrum acuminatum is Critically Mill., which has yielded an antimalarial compound, Endangered [CR B1ab(iii)12ab(iii)]. The species has malleastrumolide A (Du et al., 2017). both an extent of occurrence (EOO) and area of

VERSION OF RECORD FIRST PUBLISHED ONLINE ON 15 MAY 2020 AHEAD OF SUMMER 2020 ISSUE. doi: 10.3417/2020509 NOVON 28: 102–107. Volume 28, Number 2 P´erez & Miller 103 2020 Malleastrum (Meliaceae) from Madagascar

Figure 1. Malleastrum acuminatum V. P´erez& J. S. Mill. (P. P. Lowry II, A. Rakotozafy & M. Nicoll 4046; holotype, MO). 104 Novon

occupancy (AOO) below the threshold for Critically Distribution and habitat. Malleastrum longifoliolatum Endangered. All four known collections are from is known from dry western forests at low elevations just to essentially a single locality to the northwest of Masoala the east of the city of Mahajanga. National Park, in an area that is not protected and is IUCN Red List category. Malleastrum longifoliola- being degraded; thus, following IUCN criteria, there is a tum is known from only three collections, all from the single location with respect to the threat of anthropo- Mahajanga region, but two of the collections do not have genic habitat loss or damage, and continuing loss or precise locality information that allows the species to be damage may be projected. mapped, so the species is best considered Data Defi- Discussion. Malleastrum acuminatum is a very dis- cient (DD). In all likelihood it is probably critically tinct species that is known only from a very limited area endangered. on the Masoala Peninsula. Its most distinct feature, which makes it easily separable from all other species, is Discussion. Malleastrum longifoliolatum differs its large leaves with elliptic to oblong leaflets with from all other species of Malleastrum in having pin- distinctly acuminate apices. It most closely resembles nately compound leaves with leaflets that are 6 times M. mocquerysi. Both have relatively large leaves for longer than wide. It is one of the few species with a Malleastrum, but the structure and shape of the leaflets restricted distribution in western Madagascar near are quite different. Malleastrum mocquerysi has oblong, Mahajanga. Malleastrum longifoliolatum most closely coriaceous leaflets, with variable but generally acute resembles M. gracile, but M. gracile may have up to 11 and abruptly short-acuminate apices, that dry dark leaflets, which are only about three times as long as green. That species is known from the island of Nosy wide, and the petiole is prominently winged. That spe- Mangabe, the adjacent Masoala Peninsula, and near the cies is widespread in dry regions of western to central town of Daraina to the north. Madagascar. Malleastrum longifoliolatum has unusual venation in that some of the secondary veins loop into Paratypes. MADAGASCAR. Analanjirofo [Toamasina]: and connect with the next upper secondary, while others Maroantsetra, trail above and to the NNE of village of Hiaraka, end near, but not at the margin without connecting to ESE of Maroantsetra, across bay, on NW coast of Masoala Peninsula, 15°299S, 49°559E, 8 Oct. 1986, P. P. Lowry, A. any other secondary. Rakotozafy & M. Nicoll 4015 (MO); Maroantsetra, trail E of Paratypes. MADAGASCAR. [Mahajanga]: village of Hiaraka, toward the rock, ESE of Maroantsetra, across Mahajanga, June 1953, Bosser 5844 (P), Bosser 5880 (P). bay, on NW coast of Masoala Peninsula, 15°309S, 49°569S, 9 Oct. 1986, P. P. Lowry, A. Rakotozafy & M. Nicoll 4040 (MO); 3. Malleastrum obovatum V. P´erez& J. S. Mill., sp. Maroantsetra, ridge running SE of village of , along nov. TYPE: Madagascar. Alaotra-Mangoro [Toa- ridge SE of Androka River, SE of Maroantsetra, NW coast of 9 0 Masoala Peninsula, 15°389S, 49°590E, 15 Oct. 1986, P. P. masina]: Parc National de Zahamena, 17°28 28 S LowryA.Rakotozafy&M.Nicoll4142(MO). 48°449120E, 16 July 2000, L. M. Randrianjanaka et al. 564 (holotype, MO!; isotypes, CNARP not 2. Malleastrum longifoliolatum V. P´erez & J. S. seen, P image!, TEF not seen). Figure 3. Mill., sp. nov. TYPE: Madagascar. Boeny [Maha- janga]: Belobaka, Station Forestiere Marohogo, a Diagnosis. Malleastrum obovatum V. P´erez& J. S. Mill. is l’Est de la Station, 15°439040S 46°309080E, 10 distinguished from M. rakotozafyi Cheek in having obovate – – Dec. 2005, T. Andriamihajarivo et al. 829 (holo- leaflets 30 62 mm long (vs. ovate-elliptic, 19 42 mm long) and longer (8–15 mm vs. 4–5 mm), ebracteate peduncles. type, MO!; isotypes, P image seen, TAN not seen, TEF not seen). Figure 2. Tree to 11 m tall; twigs gray to dark brown with prominent light brown lenticels, strigillose with white, Diagnosis. Malleastrum longifoliolatum V. P´erez& J. S. , Mill. differs from all other species of Malleastrum (Baill.) J.-F. short, 0.25 mm, appressed hairs throughout. Leaves Leroy in having leaflets that are 6 times longer than wide. unifoliate; leaflet lamina chartaceous to leathery, drying dark brown, obovate, 30–62 3 24–41 mm, apex obtuse Shrub to 3 m tall; twigs dark brown with prominent to rounded, base cuneate, sometimes asymmetrically so; light brown lenticels. Leaves pinnately compound, with 3 or 5 leaflets; leaflets chartaceous, drying light green, margin entire; venation brochidodromous, midrib, sec- spatulate, 36–58 3 5–8 mm, 6 times longer than wide, ondary and tertiary veins prominent on adaxial and terminal leaflet longer than lateral apical leaflets when abaxial surfaces, midrib strigillose; petiole articulate mature, apex rounded to acute, base attenuate; margin with lamina, indistinctly to prominently winged, wing up entire; venation pinnate, midrib, secondary and tertiary to 5–7 3 1–2 mm, strigillose. Flowers solitary, opposite; veins prominent on adaxial and abaxial surfaces; petiole peduncle 8–15 3 0.5–1 mm, ebracteate; pedicel artic- 16–18 mm, lacking a distinct wing. Flowers not seen. ulate with peduncle, 2–3 3 ca. 0.5 mm, strigillose; Infructescences axillary panicles. Fruit a berry, red, 1 3 flower buds covered with short, white, appressed hairs; 0.5 mm; apex rounded. calyx green, campanulate, ca. 2 mm, 5-lobed, lobes 1 3 Volume 28, Number 2 P´erez & Miller 105 2020 Malleastrum (Meliaceae) from Madagascar

Figure 2. Malleastrum longifoliolatum V. P´erez& J. S. Mill. (T. Andriamihajarivo et al. 829; holotype, MO). 106 Novon

Figure 3. Malleastrum obovatum V. P´erez& J. S. Mill. (L. M. Randrianjanaka et al. 564; holotype, MO). Volume 28, Number 2 P´erez & Miller 107 2020 Malleastrum (Meliaceae) from Madagascar

ca. 1 mm, strigillose; petals yellow-orange abaxially, was cited, but the species was simply designated as white adaxially; mature flowers unknown. Fruit a berry, likely to be new to science. The species is now known orange-brown, broadly ellipsoid, 16–18 3 11–13 mm, from five collections, three from the region of the Re- apex acuminate to rounded, base obtuse, strigillose or serve Naturelle de Zahamena, one from the region of the glabrous. foretˆ de Vohimanana in the region, and one from the Masoala Peninsula. Distribution and habitat. Malleastrum obovatum is native to humid low- to mid-elevation forests of central Paratypes. MADAGASCAR. Alaotra-Mangoro [Toa- eastern Madagascar. masina]: Ambatondrazaka, commune Manakambahiny Est, fokontany Sahamalaza, hameau Nonokambo, Reserve Nature- IUCN Red List category. This species is known from lle Integrale de Zahamena, foretˆ Alaindrotra, bord de l’Onibe, 9 0 9 0 three localities and appears reasonably widespread in 17°45 07 S 48°43 01 E, 2 Mar. 2001, Randrianjanaka et al. 601 (CNARP not seen, MO); Parc National de Zahamena, eastern Madagascar with an EOO above the threshold Antandava, Ankosy, 17°289480S 048°449040E – 048°539580E, for any Threatened category. While its AOO would be 996–1250 m, 12 July 2000, Ratovoson et al. 249 (CNARP below the threshold for Endangered, the three known not seen, MO). Analanjirofo [Toamasina]: Masoala Peninsula, localities are significantly distant from one another S of village of Ambanizana in Andranobe River watershed, 400–1700 m from seashore, 15°409240S 049°579510E, and a great deal of intact forest exists in the area between 110–260 m, 28 Dec. 1994, Vasey et al. 282 (MO). Atsinanana these localities, so it is likely more common than [Toamasina]: Brickaville, Maroseranana, Ambodilendemy, vers documented by collections. Parts of its habitat are le sommet d’Ankerana, foret de Vohimanana, 18°249260S protected. Given the paucity of known localities, the 048°479310E, 1169 m, 25 Mar. 2011, Ravelonarivo & Felix species should be considered Data Deficient (DD), 3860 (MO). although further collecting in a very poorly known region Acknowledgments. Funding for the first author’s from which few collections exist may prove it to be Least participation was provided by the U.S. National Science Concern (LC). Foundation’s Research Experiences for Undergraduates Discussion. Malleastrum obovatum is unusual in the program (grant number NSF-1851727). The following genus with its unifoliolate, obovate leaves on a winged, people at the Missouri Botanical Garden assisted in this articulate petiole. The most similar species is M. rako- project: M´onica Carlsen, Wendy Applequist, Pete Lowry, tozafyi, which is also usually unifoliolate but differs in Armand Randrianasolo, Heidi Schmidt, Mary Stiffler, having ovate-elliptic leaf blades 19–42 mm long (Cheek, and Charlotte Taylor. 1990), as opposed to the distinctly obovate leaf blades, 30–62 mm long, in M. obovatum. Additionally, M. Literature Cited rakotozafyi has shorter, bracteate peduncles. Malleas- Cheek, M. 1990. A new species of Malleastrum (Meliaceae) trum pseudodepauperatum J.-F. Leroy known from the from Madagascar. Kew Bull. 1: 717–720. Montagne d’Ambre region shares similarly sized, obovate Du, Y., A. K. Abedi, A. L. Valenciano, M. L. Fern´andezMurga, leaflet blades with M. obovatum, but its leaves are trifo- M. B. Cassera, V. E. Rasamison, W. L. Applequist, et al. 2017. Isolation of the new antiplasmodial butanolide, liolate and the petioles are not articulate and lack malleastrumolide A, from Malleastrum sp. (Meliaceae) from prominent wings. The fruits of M. obovatum are larger Madagascar. Chem. Biodivers. 14: 12. than those of most species for which fruit is known. Fosberg, F. R. 1974. Miscellaneous notes on the flora of Malleastrum obovatum was found during fieldwork as Aldabra and neighbouring islands: III. Kew Bull. 29: – part of a program sponsored by the National Institutes of 253 266. ’ IUCN. 2012. IUCN Red List Categories and Criteria, Version Health s International Cooperative Biodiversity Pro- 3.1. Second edition. Prepared by the IUCN Species Survival gram administered from the Fogarty International Pro- Commission. IUCN, Gland, Switzerland; Cambridge, United gram for a multi-institutional effort to find plants with Kingdom. possible medicinal value. The species first came to light Leroy, J. F. 1960. Contributionsal ` ’´etude des foretsˆ de Madagascar. J. Agric. Tradit. Bot. Appl. 7: 379–382. because samples of it yielded a novel antiplasmodial Leroy, J. F. & M. Lescot. 1996. Taxons nouveaux de Trichilieae butanolide, malleastrumolide A (Du et al., 2017). In Du (Meliaceae- Melioideae) de Madagascar. Bull. Mus. Natl. et al.’s publication the voucher specimen for the sample Hist. Nat., s´er.4, sect. B. Adansonia 18(1–2): 3–4.

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