Bowiea Harv. ex T.Moore & Mast.

Martínez-Azorín, Mario, Crespo, Manuel B., Alonso-Vargas, María Ángeles, Pinter, Michael, Crouch, Neil R., Dold, Anthony P., Mucina, Ladislav, Pfosser, Martin & Wetschnig, Wolfgang, 2023, A generic monograph of the Hyacinthaceae subfamily Urgineoideae, Phytotaxa 610 (1), pp. 1-143 : 33-35

4. Bowiea Harv. ex T.Moore & Mast.

in Gard. Chron. 1866: 971 (1866), nom. cons. [non Bowiea Haw. in Philos. Mag. J. 64: 299 (1824), Asphodelaceae ] ( Figs 16 , 17 ) ≡ Bowiea Harv. ex Hook.f. in Bot. Mag. 93: t. 5619 (1867) [isonym, Art. 14 Note 1 of the ICN]. Typus generis:— Bowiea volubilis Harv. ex T.Moore & Mast. (holotype). Note:—The earliest known description of this name was published in The Gardeners’ Chronicle (issue dated 13 October 1866) as part of an unsigned short note attributable to the journal editors, Thomas Moore and Maxwell T. Masters. These authors validated simultaneously the species name B. volubilis as a result of a “descriptio generico-specifica” (Art. 38.5 of the ICN) based on material collected by Cooper in South Africa and grown at Kew, but they attributed the authorship of the new genus and species to William H. Harvey. Only a few months later, Hooker (1867) described and illustrated the same plant and commented in detail on the provenance of all material gathered by that time, including Cooper’s plants at Kew. As all those names share the same type material, Hooker’s newly described genus and species are therefore treated as later isonyms. However, Bowiea Harv. ex T.Moore & Mast. was illegitimate when published, since it was homonymous with Bowiea Haw. (Asphodelaceae) , but it is currently treated as a conserved name.According to Art. 14 Note 1, the authorship of both generic and specific names is that of the earliest isonym, which is adopted here.

≡ Ophiobostryx Skeels in Bull. Bur. Pl. Industr. U.S. D.A. 223: 45 (1911), syn. subst. Typus generis:— O. volubilis (Harv. ex T.Moore & Mast.) Skeels (holotype).

≡ Schizobasopsis J.F.Macbr. in Contr. Gray Herb. n.s. 56: 3 (1918), syn. subst. Typus generis:— S. volubilis (Harv. ex T.Moore & Mast.) J.F.Macbr. (holotype).

Description:—Bulbous geophyte. Bulb partially epigeal and photosynthetic. Roots thickened and branched. Leaves 1‒2, narrowly lanceolate, canaliculate, green, smooth, glabrous, up to 20 cm long, somewhat succulent, only appearing in young plants and usually absent in adult plants at anthesis. Inflorescence up to 5 m long but usually shorter, strongly branched, twining, succulent, smooth, glossy green or glaucous, prostrate to climbing on other plants and rocks; peduncle green, terete, twining and succulent; pedicels curved, to 7 cm long. Bracts lanceolate, green, appressed to peduncle, lowermost with spur that usually clasps stem; bracteoles absent. Flowers stellate, erect-patent, diurnal, lasting up to 10 days. Tepals 6, biseriate, 4‒10 mm long, lanceolate to ovate, white to greenish, with greenish longitudinal band on abaxial side, almost free above joint with ovary, long lasting after capsule development, not abcissing from base. Stamens 6, spreading, not connivent to style; filaments filiform, free; anthers dorsifixed, dehiscing by longitudinal slits along their whole length. Ovary conical, wide and short, disposed on wide thickened obtriangular receptacle, giving the impression of semi-inferior ovary, green, slightly trigonous, with ca. 5‒8 ovules per locule. Style 2‒4 mm long, erect, white, with trigonous stigma. Capsules ovate to subglobose, truncate to acute, 8‒30 mm long, green, fleshy first and papyraceous after ripening, valves completely dehiscing from base. Seeds subhemispheric to subfusiform, with prominent embryo and very narrow, winged margins, 3.8‒5.0 mm long, with black, glossy testa and subisodiametric or sightly elongated cells, with slightly sunken, periclinal walls.

Number of species and distribution:— Bowiea includes 2 species ( Reid et al. 1990): B. gariepensis Van Jaarsveld (1983: 343) occurring in arid regions of northwestern South Africa and southern Namibia (restricted to the Karoo-Namib Region), and B. volubilis (currently including also B. kilimandscharica Mildbraed 1934: 202 ) distributed in tropical and subtropical regions from southeastern South Africa to East Africa ( Fig. 8 ). It is restricted to the Uzambara-Zululand and the Zambezian Subregion (sensu Takhtajan 1986 and Martínez-Azorín et al. 2023a). A disjunt record of Bowiea from Angola [Huíla, a 11 kms de Sá da Bandeira [Lubango] estrada para a Tunda-Vala, 13/02/1963, H. Enriques 117 (K!)] references white flowers, indicating a possibility that this specimen belongs to B. gariepensis , requiring further studies for confirmation.

Both species are differentiated in morphological, ecological, and biogeographical terms ( Baker 1873b, Dyer 1941, Jessop 1977, Stedje & Thulin 1995, Stedje 1996, Van Jaarsveld 1983 , 1992, Reid et al. 1990). For further information on Bowiea species see Hooker (1867), Skeels (1911), Barschus (1954), Van Jaarsveld (1983, 1992), and Reid et al. (1990).

Karyology:—2n=20 ( Schnarf & Wunderlich 1939, D’Amato 1949, De Wet 1957, Jones & Smith 1967, Bruyns & Vosa 1987, Stedje & Nordal 1987).

History, diagnostic characters, and taxonomic relationships:— Bowiea is unmistakable by a distinct syndrome of morphological characters ( Figs 16–17 ), such as branched, fleshy inflorescence; long lasting flowers with nearly free tepals that remain at the base of the mature capsule; and very wide, short, conical ovary disposed on a wide thickened obtriangular receptacle, giving the impression of a semi-inferior ovary, facilitating its acceptance by all researchers working on Urgineoideae since its description by Hooker (1867), including the treatments presented by Manning et al. (2004) and Manning & Goldblatt (2018). Our phylogenetic analyses ( Martínez-Azorín et al. 2023a) place all studied samples of Bowiea into a well-supported, sister clade to the remaining Urgineoideae in agreement with previous works ( Pfosser & Speta 1999, 2001, 2004, Manning et al. 2004, Pfosser et al. 2012). Only Schizobasis shares the branched inflorescence with Bowiea , however, the former genus clearly differs by the wiry inflorescence (it is never succulent), the flowers having a well differentiated superior ovary, and the withered perigone persisting above the capsule as a cap, together with its distant phylogenetic relationship ( Martínez-Azorín et al. 2023a).

Accepted species:—

Bowiea gariepensis van Jaarsv. in J. S. African Bot. 49(4): 343 (1983) ≡ B. volubilis subsp. gariepensis (van Jaarsv.) Bruyns in Caryologia 40(4): 291 (1988) ( Figs 1.17 , 16.3 , 17.1 ). Type:— SOUTH AFRICA. Northern Cape. Pofadder (2919): Upper south slope of Groot Pellaberg, (–AA), 10 August 1982, Van Jaarsveld 6650 (NBG127051! holo.: two herbarium sheets numbered -1 & -2; PRE iso.).

Bowiea volubilis Harv. ex T.Moore & Mast. in Gard. Chron. 1866: 971 (1866) ≡ Ophiobostryx volubilis (Harv. ex T.Moore & Mast.) Skeels in Bull. Bur. Pl. Industr. U.S. D.A. 223: 45 (1911) ≡ Schizobasopsis volubilis (Harv. ex T.Moore & Mast.) J.F.Macbr. in Contr. Gray Herb. 56: 3 (1918) ( Figs 1.18 , 16.1, 16.2 , 17.2 ). Type:— SOUTH AFRICA. Natal [KwaZulu-Natal], 1862, T. Cooper 3263 (K s.n.! lecto. designated as “ holotype ” by Stedje & Thulin in Nordic J. Bot. 15(6): 601. 1995).

= B. kilimandscharica Mildbr. in Notizbl. Bot. Gart. Berlin-Dahlem 12: 202 (1934) ≡ Schizobasopsis kilimandscharica (Mildbr.) Barschus in Kakteen And. Sukk. 5: 65 (1954). Type:— KENYA. Kilimandscharo: Nordseite, Loitokitok, Buschsavanne, elev. 1800 m, 04 April 1934, H.J. Schlieben 5018 (BR876309!, lecto. designated as “ holotype ” by Stedje & Thulin in Nordic J. Bot. 15(6): 601. 1995; S- G-7939!, Z-000086938! isolecto.).

Figures

FIGURE 1. Seed morphology in Urgineoideae. 1. Aulostemon mzimvubuensis (van Jaarsv.) Mart.-Azorín et al.; 2. Austronea barkerae (Oberm.ex J.C.Manning & Goldblatt) Mart.-Azorín et al.; 3. Austronea grandiflora Mart.-Azorín et al.; 4. Austronea hispidoplicata Mart.- Azorín et al.; 5. Austronea linearis Mart.-Azorín et al.; 6. Austronea oblongifolia Mart.-Azorín et al.; 7. Austronea olifanta Mart.-Azorín et al.; 8. Austronea pinguis Mart.-Azorín et al.; 9. Boosia flagellaris (T.J.Edwards et al.) Mart.-Azorín et al.; 10. Boosia macrocentra (Baker) Speta; 11. Boosia modesta (Baker) Mart.-Azorín et al.; 12. Boosia natalensis (Baker) Mart.-Azorín et al.; 13. Boosia nyasae (Baker) Mart.-Azorín et al.; 14. Boosia rubella (Baker) Mart.-Azorín et al.; 15. Boosia saniensis (Hilliard & B.L.Burtt) Mart.-Azorín et al.; 16. Boosia tenella (Baker) Mart.-Azorín et al.; 17. Bowiea gariepensis van Jaarsv.; 18. Bowiea volubilis Harv. ex T.Moore & Mast.; 19. Drimia elata Jacq. ex Willd.; 20. Drimia haworthioides Baker. All to the same scale in mm.

FIGURE 8. Approximate distribution ranges of accepted genera in Urgineoideae.

FIGURE 16. Bowiea volubilis Harv. ex T.Moore & Mast. from: 1. Hooker f. (1867); 2. Dyer (1941); and 3. Bowiea gariepensis van Jaarsv. from Reid et al. (1990: pl. 2007).

FIGURE 17. Species of Bowiea Harv. ex T.Moore & Mast. displayed in horizontal rows of images. 1. Bowiea gariepensis van Jaarsv.; 2. Bowiea volubilis Harv. ex T.Moore & Mast.