Schizobasis Baker

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 : 80-84

18. Schizobasis Baker

in J. Bot. 11: 105 (1873) ( Figs 44–46 ). Typus generis:— S. macowanii Baker (holotype). ≡ Drimia sect. Schizobasis (Baker) J.C.Manning & Goldblatt in Strelitzia 40: 142 (2018). Typus sectionis:— S. macowanii Baker (holotype).

Description:—Small bulbous geophyte. Bulb hypogeal or epigeal, solitary or clump forming, ovoid to globose, up to 7 cm in diam., scales compact, white to pinkish. Roots thickened and branched. Leaves 1‒2, only present in immature plants, filiform, green, smooth, glabrous. Inflorescence distinctly branched, paniculate, 5‒30 cm long, erect to prostrate, sometimes twining and climbing on vegetation or rocks, green, commonly long lasting and photosynthetic, smooth or papillose. Peduncle green to purplish, 5‒10 cm long, terete, erect and straight to prostrate or twining, sometimes flexuose at base, glabrous or minutely papillose. Pedicels 4‒10 mm long, smooth to papillose, straight to sinuous and twining, green and long lasting supporting ripe capsules. Bracts ovate lanceolate, green, lowermost with short spur. Bracteoles absent. Flowers stellate to campanulate, erect to nodding, diurnal. Tepals 6, biseriate, lanceolate to ovate, 2.5‒5.0 mm long, white to yellowish, with darker longitudinal band, free or very shortly connate at base, suberect, patent or reflexed. Stamens 6, incurved and connivent to style or spreading; filaments filiform, 2‒4 mm long, straight to sigmoid; anthers oblong to sagittate, with apiculate connective, dehiscing longitudinally along whole length. Ovary ovoid to subglobose, green or yellowish; style erect, white, straight or sigmoid, as long as or longer than ovary; stigma minutely trigonous. Capsules ovate to subglobose, 3‒5 mm long, trigonous, loculicidal, the 3 valves splitting to base, with withered perigone segments circumscissile below and forming an apical cap. Seeds ellipsoid to subfusiform, 1.8‒3.0 mm long, flattened with prominent central embryo and short wings, black, glossy, with somewhat sinuous anticlinal testa cell walls.

Number of species and distribution:— Schizobasis includes eleven species, occurring mainly in Southern Africa, and extending to Angola and East Africa ( Fig. 29 ). In terms biogeographic phytochoria, it is restricted to the Cape, Karoo-Namib and Uzambara-Zululand Regions and the Zambezian Subregion (sensu Takhtajan 1986 and Martínez-Azorín et al. 2023a). For further information on Schizobasis see Manning & Goldblatt (2018), whilst noting that we accept most species described in the genus, based on their morphological differences. Our field work has confirmed large variation in flower morphology and habit in Schizobasis ( Figs 44 , 46 ). Further studies based on living material are urgently required to clarify the taxonomy of this genus.

Karyology:—2n=18 ( Bruyns & Vosa 1987, as S. intricata ); 2n=20 ( Watters & Ornduff 1985, as Schizobasis intricata Baker ; Jones & Smith 1967, as Schizobasis sp. ).

History, diagnostic characters, and taxonomic relationships:— Baker (1873a) described Schizobasis , a very distinct genus characterised by the slender, wiry, flexuose, branched inflorescence, also commenting on its similarity with Bowiea and other genera. Schizobasis has been accepted by most researchers in Urgineoideae based on its unique syndrome of morphological characters ( Baker 1873b, 1874 a, 1876, 1898, Bentham & Hooker 1883, Merxm̧ller 1970, Jessop 1977, Stedje 1997, Speta 1998a, 1998b, Pfosser & Speta 2001, Demissew & Nordal 2010, Martínez-Azorín et al. 2015). However, other recent studies merge Schizobasis into a widely-conceived Drimia sensu lato (Golblatt & Manning 2000, Manning et al. 2004, 2014, Manning & Goldblatt 2018), but accept Bowiea with similarly branched inflorescence as an independent genus based on their phylogenetic relationships.

The phylogenetic studies of Pfosser & Speta (2001, 2004), Manning et al. (2004), and Pfosser et al. (2012) have shown that Schizobasis is sister to Litanthus . The phylogenetic analyses of Martínez-Azorín et al. (2023a) agree with the previous molecular studies and place eleven samples of Schizobasis in a monophyletic clade sister to Litanthus , the latter relationship being supported by anther and seed morphology. Therefore, we maintain here Schizobasis at genus rank as it is easily identifiable by the branched and wiry inflorescences, flowers with tepals only shortly fused at base, apiculate stamen connective, and angled seeds. We here accept all described species in the genus based on their morphological differences although a detailed taxonomic revision of the genus is needed to ascertain the real diversity of the genus.

Accepted species and required new combination:—

Schizobasis angolensis Baker in Trans. Linn. Soc. London, Bot. 1(5): 255 (1878). Type:— ANGOLA. Pungo Andongo , ad rupes ipsius Praesidii, 2400–3800 ft., August 1857, F. Welwitsch 3867 (LISU 222125! holo.; as “ Adenoteca aphylla Welw. gen. nov. ” in sched.). Note:—The collection “Pungo Andongo, 2400–3800 ft., F. Welwitsch 3866 (K000257004!, LISU222126!)” is most probably original material of that name.

= Adenoteca aphylla Welw. , nom. nud. in sched. et in protolog.

Schizobasis buchubergensis Dinter in Repert. Spec. Nov. Regni Veg. 30: 80 (1932). Type:— NAMIBIA. Bogenfels (2715): Buchuberge, (–DD), 7 July 1929, Dinter 6493 (B, holo., not seen; on loan to D. M̧ller-Doblies since 1980, R. Vogt pers. comm.).

Schizobasis cuscutoides (Burch. ex Baker) Benth. & Hook.f., Gen. Pl. [Bentham & Hooker f.] 3(2): 786 (1883) ≡ Asparagus cuscutoides Burch. ex Baker in J. Linn. Soc., Bot. 14: 606 (1875), basionym ≡ Drimia cuscutoides (Burch. ex Baker) J.C.Manning & Goldblatt in Strelitzia 9: 711 (2000) ( Figs 44.1 , 45C–E ). Type:— SOUTH AFRICA. Northern Cape: Caput Bonae Spei, in saxosis aridis ad ripas fluminis Gariep, 1 March 1813, Burchell 2673 (K000257125!, lecto. designated as holo. by Manning et al. in S. African J. Bot. 94: 264. 2014; L, P01775622!, isolecto.).

Schizobasis dinteri K.Krause in Bot. Jahrb. Syst. 48(3–4): 355 (1912). Type:— NAMIBIA. Mariental (2417): Gross Namaland , bei Marienthal [Mariental] in der Kiesw ̧ste unterhalb des Staudammes, (–DB), 20 March 1911, Dinter 2005 (SAM0073821-0! lecto. designated by Manning et al. in S. African J. Bot. 94: 264. 2014; SAM 0004463-0! isolecto.).

Schizobasis gracilis R.E.Fr. in Wiss. Ergebn. Schwed. Rhodesia-Kongo-Exped. 1911–1912(1): 227 (1916). Type:— ZAMBIA. Rhodesia bor. orient.: pr. rivulum Kalungwisi, October 1911, R.E. Fries 1157 (UPS [V-041106]! holo.).

Schizobasis intricata (Baker) Baker in J. Bot. 12: 368 (1874) ≡ Anthericum intricatum Baker in J. Bot. 10: 140 (1872), basionym ≡ Drimia intricata (Baker) J.C.Manning & Goldblatt in Strelitzia 9: 712 (2000) ( Figs 4.4 , 44.2 , 45A–B ). Type:— SOUTH AFRICA. Cape, Zeyher 4284 (K000257121! lecto. designated as holo. by Stedje & Thulin in Nordic J. Bot. 15: 600. 1995; SAM0022792-0 isolecto.).

Schizobasis macowanii Baker in J. Bot. 11: 105 (1873) ( Figs 4.5 , 44.3 ). Type:— SOUTH AFRICA. Eastern Cape. Somerset East (3225): inter frutices prope Somerset East , (–DA), elev. 2500–3000 ft., October, MacOwan 1847 (K000257123! lecto. designated by Manning et al. in S. African J. Bot. 94: 264. 2014; BOL!, SAM 0022788-0 isolecto.).

Schizobasis schizobasoides (J.C.Manning & J.M.J.Deacon) Mart. - Azorín, M.B. Crespo, M. Pinter & Wetschnig in Phytotaxa 397(4): 294 (2019) ≡ Drimia schizobasoides J.C.Manning & J.M.J.Deacon in Strelitzia 40: 142 (2018), basionym ( Fig. 46.1 ). Type:— SOUTH AFRICA. Northern Cape. Springbok (2917): Karrachabpoort , (–AC), 23 December 2015, J.M.J. Deacon 3915 (NBG holo.).

Schizobasis schlechteri Baker in Bull. Herb. Boissier ser. 2, 1: 783 (1901) ( Fig. 46.2 ). Type:— SOUTH AFRICA. Eastern Cape. Umtata (3128): Şdwest-Afrika (Natal) [sic.], regio orientalis prope Umtata , (–DB), elev. 3400 ft., 18 January 1895, R. Schlechter 6327 (Z000086084! lecto. designated by Manning et al. in S. African J. Bot. 94: 264. 2014; GRA!, BOL!, PRE! isolecto.).

Schizobasis sigmoidea (J.C.Manning & J.M.J.Deacon) Mart. - Azorín, M.B. Crespo, M. Pinter & Wetschnig in Phytotaxa 201(2): 168 (2015) ≡ Drimia sigmoidea J.C.Manning & J.M.J.Deacon in S. African J. Bot. 94: 267 (2014), basionym ( Figs 4.6 , 46.3 ). Type:— SOUTH AFRICA. Western Cape. Montagu (3320): Ashton , Wolwendrift , cliff face in large kloof, (–CC), 23 September 2013, J.M.J. Deacon, D. Gwynne-Evans & R. McKenzie 2820 (NBG holo.; MO iso.).

= Schizobasis bruce-bayeri U. & D. M̧ll.-Doblies, nom. nud. in sched.: SOUTH AFRICA. Swellendam, Bonnievale, R. Marloth 11997 (NBG!).

Schizobasis visagieae (van Jaarsv.) Mart. -Azorín, M.B.Crespo & M.Á.Alonso comb. & stat. nov. ≡ Drimia intricata (Baker) J.C.Manning & Goldblatt var. visagieae Van Jaarsv. in Bradleya 32: 78 (2014), basionym. Type:— ANGOLA. 1413 (Lubango): Cliffs at Tundavala, west of Lubango, (–DC), 14 July 2010, Van Jaarsveld & Harrower 23119 (LUB holo.; NBG iso.).

Figures

FIGURE 4. Seed morphology in Urgineoideae. 1. Rhodocodon rotundus H.Perrier ex Knirsch et al.; 2. Rhodocodon siederi Knirsch et al.; 3. Rhodocodon urgineoides Baker; 4. Schizobasis intricata (Baker) Baker; 5. Schizobasis macowanii Baker; 6. Schizobasis sigmoidea (J.C.Manning & J.M.J.Deacon) Mart.-Azorín et al.; 7. Sekanama brachystachys (Baker) Mart.-Azorín et al.; 8. Sekanama porphyrostachys (Baker ex Balf.f.) Mart.-Azorín et al.; 9. Sekanama sanguinea (Schinz) Speta; 10. Squilla hesperia (Webb & Berthel.) Mart.-Azorín et al.; 11. Squilla maritima (L.) Steinh.; 12. Squilla palaestina (M.B.Crespo et al.) Mart.-Azorín et al.; 13. Squilla pancration Steinh.; 14. Squilla secundiflora (Maire) Mart.-Azorín et al.; 15. Squilla serotina (Schousb.) Mart.-Azorín et al.; 16. Squilla undulata (Desf.) Mart.-Azorín et al.; 17. Striatula oliverorum (J.C.Manning) M.Pinter et al.; 18. Striatula platyphylla (B.Nord.) M.Pinter et al.; 19. Tenicroa exuviata (Jacq.) Speta; 20. Tenicroa fragrans (Jacq.) Raf. All to the same scale in mm.

FIGURE 29. Approximate distribution ranges of accepted genera in Urgineoideae.

FIGURE 44. Species of Schizobasis Baker displayed in horizontal rows of images. 1. Schizobasis cuscutoides (Burch. ex Baker) Benth. & Hook.f.; 2. Schizobasis intricata (Baker) Baker; 3. Schizobasis macowanii Baker.

FIGURE 45. Species of Schizobasis Baker from Krause (1930: 290). A−B. Schizobasis intricata (Baker) Baker; C−E. Schizobasis cuscutoides (Burch. ex Baker) Benth. & Hook.f.

FIGURE 46. Species of Schizobasis Baker displayed in horizontal rows of images. 1. Schizobasis schizobasoides (J.C.Manning & J.M.J.Deacon) Mart.-Azorín et al.; 2. Schizobasis schlechteri Baker; 3. Schizobasis sigmoidea (J.C.Manning & J.M.J.Deacon) Mart.- Azorín et al.