See discussions, stats, and author profiles for this publication at: https://www.researchgate.net/publication/274013458 Taxonomic revision of the genus Heliotropium (Boraginaceae s.l.) in south Yemen Article in Nordic Journal of Botany · August 2015 DOI: 10.1111/njb.00746 CITATION READS 1 989 3 authors, including: Asma'a Olwey Assiut University 7 PUBLICATIONS 3 CITATIONS SEE PROFILE Some of the authors of this publication are also working on these related projects: Taxonomic studies on the family Leguminosae in Egypt View project All content following this page was uploaded by Asma'a Olwey on 26 December 2017. The user has requested enhancement of the downloaded file. Nordic Journal of Botany 33: 401–413, 2015 doi: 10.1111/njb.00746, ISSN 1756-1051 © 2015 The Authors. Nordic Journal of Botany © 2015 Nordic Society Oikos Subject Editor and Editor-in-Chief: Torbjörn Tyler. Accepted 5 December 2014 Taxonomic revision of the genus Heliotropium (Boraginaceae s.l.) in south Yemen Salah El Naggar, Azza El-Hadidy and Asmaa Olwey S. M. El Naggar and A. O. Olwey ([email protected]), Botany and Microbiology Dept, Faculty of Science, Assiut Univ., Assiut, Egypt. – A. H. El-Hadidy, Botany Dept, Faculty of Science, Cairo Univ., Cairo, Egypt. The flora and fauna of Arabia, particularly southern Yemen, has recently attracted the interest of many authors. In this study, the genus Heliotropium L. (Boraginaceae) is taxonomically revised in southern Yemen. Ten species are recognized. Nomenclature, typification, representative specimens and a diagnostic key to all species are provided, along with their distribution in southern Yemen. The taxonomically most valuable characters in the genus are those of flowers (calyx, corolla, androecium and gynoecium) and nutlets, and those characters are thoroughly investigated and discussed. Both light and scanning microscopy are used in the investigation. Papillate anther apices (brush-like) were recognized in some species. Connate anthers and deep or shallow ventral circular depressions on the nutlets were found to be useful in distinguishing members of H. sect. Orthostachys (viz. H. strigosum, H. rariflorum and H. ovalifolium), while winged nutlets were found only in H. pterocarpum. The length and hairiness of the style and stigma also proved to be taxonomically useful. Boraginaceae s.l. is one of the largest families of dicoty- system of five genera was initially suggested: Euploca Nutt., ledonous angiosperms. On the account of its broadly Heliotropium L., Ixorhea Fenzl, Myriopus Small and Tourne- drawn limits, it faces some debate on both the ordinal fortia L. Recently, the genus Euploca Nutt. has increasingly and the infra-familiar levels. It was placed in an uncer- accepted as a valid genus (Melo and Semir 2006, 2009, 2010, tain ordinal position by the Angiosperm Phylogeny Melo et al. 2009, Acevedo-Rodríguez and Strong 2012, Group, APG III (2009) [Eudicots – Asterids, subgroup Degen Naumann and Melo 2012), While,the validity of the Euasterids I]. The phylogenetic relationships within genus Tournefortia L. as a separate genus has become the family are still unclear. Currently, a concept of six questioned and some authors prefer to nest it within sub-families (Codonoideae, Wellstedioideae, Cordioideae, Heliotropium L. (Craven 2005, Luebert et al. 2011). Ehretioideae, Heliotropioideae and Boraginoideae) is Recently, biogeographers have recognized the south- still widely accepted. However, a taxon of ordinal rank western region of the Arabian Peninsula and southern (Boraginales), comprising six smaller families (Boraginaceae Yemen as a part of the floristic hotspot the African Horn s.s., Hydrophyllaceae, Heliotropiaceae, Cordiaceae, Ehre- (Mittermeier et al. 1998, Myers et al. 2000). Heliotropium tiaceae, Codonaceae and Wellstediaceae) is increasingly L. in Arabia, and particularly in Yemen, has always been being used instead of Boraginaceae s.l (Böhle and Hilger problematic. Many species exhibit great polymorphism 1997, Ferguson 1999, Smith et al. 2000, Gottschling that make them hard to identify accurately. Hence, the et al. 2001, 2004, Stevens 2001, Hilger et al. 2005, Cohen number of Heliotropium species accepted as represented 2013, Refulio-Rodriguez and Olmstead 2014, Weigend in Yemen has changed through time. Forsskål (1775) et al. 2014). was the first to report 5 taxa belonging to Heliotropium The terminal style (in contrast to the gynobasic style in the area, while and Deflers (1889) recorded 7 species. of sub-family Boraginoideae), and its uniquely modified Recently, Gabali and Al-Gifri (1990) recorded 10 species, stigmatic head that consists of a basal annulus and a conical Wood (1997) reported the presence of 12 species, while infertile apex, are the best characters distinguishing the sub- Boulos (1988) accepted 9 species and two subspecies. family Heliotropioideae. Recently, a phylogenetic analysis The present study aims were to: 1) revise the different using data obtained by trnL and ITS 1 gene sequences taxa belonging to Heliotropium L. in the flora of Yemen, 2) supported the idea of raising Heliotropioideae to the familiar evaluate the taxonomic characters and attempt to find new rank as Heliotropiaceae Schrad. (Diane et al. 2002, Hilger ones that can be used in the classification of the genus in the and Diane 2003). At the same time, generic limits have also region, and 3) provide a revised synopsis and a diagnostic changed dramatically. Within Heliotropiaceae Schrad, a key for the genus in Yemen. 401 Material and methods 8. Heliotropium pterocarpum (A. DC.) Hochst. & Steud. ex Bunge Plant material V Section Rutidotheca (A. DC.) Verdc. 9. Heliotropium longiflorum (A. DC.) Jaub. & Spach Morphological data of Yemen taxa of Heliotropium subsp. longiflorum were scored by examination of herbarium specimens i. var. longiflorum collected from different localities in southern Yemen, ii. var. stenophylum (O. Schwartz) Verdc. representing different habitats, and kept at ASTU. Some VI. Section Zeylanica Förther Saudi Arabian specimens were also investigated. High 10. Heliotropium zeylanicum (Burm. f.) Lam. quality digital photos of type specimens and authentic material were seen by the authors as indicated by (!) in the text. Key to the species Light microscopy 1 Corolla completely yellow, or yellowish green; anthers Willd 8 and Willd 3 Zewz stereomicroscopes were bidentate …………………………… 10. H. zeylanicum used. Illustrations were made with a Camera Lucida – Corolla completely white, or tinged with yellow at the and photographs with a Canon IXUS 960 IS digital throat; anthers not bidentate ………………………… 2 camera. 2 Inflorescence bracteate; calyx-lobes unequal; nutlets with ventral cavities ……..……………..………….......… 3 Scanning electron microscopy (SEM) – Inflorescence ebracteate; calyx-lobes equal or not; Material for SEM were prepared by mounting plant nutlets with or without ventral cavities .…...…………… 4 segments onto clean stubs using double-sided cellotape. 3 Subshrubs or herbs; bracts prominent; corolla 1.5– The stubs were coated with gold in a JEOL JFC 1100 E 2.0 (–2.5) mm long; anthers with erect apiculate apex; ion sputtering device, and then examined in a JEOL JSM stigma depressed ……………………… 3. H. rariflorum 5400LV scanning electron microscopy operated at an – Herbs; bracts reduced upwards; corolla 2.0–4.0 mm accelerated voltage of 15 kV at the Electron Microscopy long; anthers with curved apiculate apex, stigma not Unit (EMU), Assiut Univ., Egypt. Terminology follows depressed …..…....…………………… 2. H. strigosum Lawrence (1959), Radford et al. (1974) and Harris and 4 Corolla 3.0–5.0 mm long; nutlets 4 …....…………… 5 Harris (1994). – Corolla 5.0–7.0 mm long; nutlets 2 or 4 .…….…… 8 5 Style obsolete; stigma sessile .…….………………… 6 – Style at least 0.2 mm long …….…………………… 7 Synopsis of the genus Heliotropium L. in 6 Greyish herb; calyx-lobes unequal with one large sepal; south Yemen corolla hairy inside; anthers connate when young; stigma with apical hairs; nutlets with ventral cavities The infra-generic classification proposed by Förther (1998) ……….……..…...…………………… 4. H. ovalifolium is followed here as outlined below, with the species (num- – Green herb; calyx-lobes equal; corolla glabrous inside; bered) represented in Yemen indicated within each section anthers not connate; stigma glabrous; nutlets without and subsection. cavities ………........…………………… 1. H. europaeum 7 Flowers lax, in 1-rank, swollen at the base; anther ovate, inserted 1.00–1.25 mm from the base; style 0.2–0.5 mm Heliotropium L. (1753, p. 130) long; stigma 0.50–0.75 mm long, glabrous, longer than the style …..……….……………… 7. H. ramosissimum Taxonomic synonyms: Euploca Nutt. (1837, p. 189). – Flowers dense, in 2-ranks, swollen at the middle; anther – Piptoclaina G. Don (1837, p. 364). – Heliophytum (Cham.) oblong-lanceolate, inserted 0.5–1.0 mm from the base; A. DC. in DC. (1845, p. 551). style 0.5–0.7 mm long; stigma 0.7–1.0 mm long, gla- I. Section Heliotropium brous, or with few scattered hairs, equaling or longer than 1. Heliotropium europaeum L. the style …….………………………. 6. H. bacciferum II. Section Orthostachys R. Br. 8 Nutlets 2 (2-seeded), with symmetric groove at apex; A. Subsect. Bracteata I. M. Johnst. leaves 0.5–4.0 0.3–2.0 cm …………...….………… 9 2. Heliotropium strigosum Willd. – Nutlets 4 (1-seeded), without groove; leaves longer i. var. strigosum and wider, up to 10.0 cm long and 7 cm wide .… ii. var. brevifolium (Wall.) C. B. Clarke ………………………………………… 9. H. longiflorum 3. Heliotropium rariflorum Stocks 9 Greyish annual; calyx-lobes unequal; stamens inserted B. Subsect. Ebracteata I. M. Johnst. below the middle of the corolla-tube; anthers 1.0–1.5 4. Heliotropium ovalifolium Forssk. mm long; style 0.5–0.7 mm long; nutlets narrowly to III. Section Pseudocoeloma Förther broadly winged …...………………. 8. H. pterocarpum 5. Heliotropium abyssinicum Vatke – Green perennial; calyx-lobes equal; stamens inserted IV. Section Pterotropium (A. DC.) Bunge above the middle and reaching the throat; anthers 6. Heliotropium bacciferum Forssk. 0.75–1.00 mm long; style 1.5–2.0 mm long, nutlets without 7. Heliotropium ramosissimum (Lehm.) Sieb. ex A. DC. wings ………………………………… 5. H. abyssinicum 402 1. Heliotropium europaeum L.