Albuca bakeri Mart.- Azorin & M.B. Crespo, 2011

Martinez-Azorin, Mario, Crespo, Manuel B., Dold, Anthony P. & Barker, Nigel P., 2011, The identity of Albuca caudata Jacq. (Hyacinthaceae) and a description of a new related species: A. bakeri, PhytoKeys 5, pp. 5-19 : 9-13

Albuca bakeri Mart.- Azorin & M.B. Crespo sp. nov.

Holotype.

SOUTH AFRICA. Eastern Cape: North of Grahamstown, on Cradock Road turn off to Kwandwe, 592 m, 05.IX.2010, 33°12'39"S, 26°24'07"E, M. Martínez-Azorín & A. Martínez-Soler 218 (GRA Holo.; ABH, K, NBG, PRE Iso.).

Diagnosis: Species insignis ex Albuca subg. Mitrotepalum characteribus floralibus ad Albucam caudatam accedit, sed valde differt et facile distinguitur bulbo hypogaeo solitario carnoso tunicis omnibus apicem attingentes in collum angustum supra solum desinentes, e basi cataphyllis albido-membranosis manifeste transversaliter fusco-striatis obtectum qui habitum pulchre zebrinum exhibent, insuper racemo subdeltoideo non secundo floribus spiraliter dispositis.

Illustrations: Baker (1869) in Refugium Botanicum, vol. 1, tab. 45 (Fig. 2); Fig. 5.

Description.

Evergreen or deciduous bulbous plants. Bulb mostly solitary, occasionally growing in small clumps, hypogeal, ovoid to spherical, 3.2-7 × 2.5-6.5 cm, with soft outer tunics that are pale and fleshy, ending in a long epigeal neck, up to 10 × 2 cm, covered with whitish open and sheathing membranous cataphylls bearing transversal sinuous ridges with their lower side pale to dark brown coloured, giving a zebra banding horizontal pattern; tunics fleshy, whitish, all reaching the top of the bulb, concentrically arranged. Roots fleshy, narrow, white, up to 90 × 2 mm. Leaves 2 -6, disposed in an apical rosette, linear-lanceolate to oblong, 9-40 × 0.4-1.3 cm, erect when young and later curving downwards, infolded, canaliculate, persistent or usually deciduous, pale bright green to glaucous, glabrous, usually minutely papillate on nerves and margins, exceptionally with long papillate margins. Inflorescence an erect raceme or subcorymb, 3-15 cm long; peduncle 9-22 cm long; pedicels helicoidally disposed, 3-7.5 cm long, longer at the base, up to 0.2-0.7 cm long near top, erect-patent; bracts ovate-lanceolate to triangular, long acuminate, 9-27 × 4-10 mm, papery white with brownish separated nerves that converge at the tips, much shorter than pedicels at least in the lower part of the inflorescence. Flowers erect; tepals white with a green median stripe 2-3 mm wide, sometimes with the tips yellowish; outer tepals lanceolate-oblong, 19-23 × 5-7 mm, with apex slightly cucullate; inner tepals ovate, 13-17 × 6-7 mm, with apex strongly cucullate. Stamens all six bearing fertile anthers; outer anthers 1.5-3 mm long, inner anthers 4-6 mm long; outer filaments 10-13.5 × 1.5-2 mm, linear lanceolate to narrowly oblong, not pinched down; inner filaments 10.5-14.5 × 2-3.5 mm, linear oblong, wider and pinched in the lower half. Ovary oblong to obovate, up to 6-7 × 2-3.5 mm, stipitate, with prominent paraseptal crests that are divergent in the lower part and form three prominent ridges; style subobpyramidal or clavate, trigonous, up to 7-11 × 3.5-4.5 mm, stigma yellowish green. Capsule ovate, 14-16 × 11-12 mm, trigonous to subsphaerical in section, pale-brown when mature; valves splitting in the upper quarter. Seeds flat, c. 4-5 × 3-4 mm, dark brown to black, flattened and semidiscoidal, biseriate and horizontally stacked in each locule. ( Fig. 5)

Flowering time.

July to September; capsules dehiscing at the end of September and November.

Habitat.

Albuca bakeri is found growing singly in dry, stony, open ground at low altitude reaching c. 650 m.

Distribution.

from Jansenville to Alice and the Keiskamma river in the Eastern Cape, with two outlying populations near Calitzdorp in the Western Cape karroo ( Fig. 6).

Diagnostic characters.

Albuca bakeri can be easily identified by its solitary hypogeal fleshy bulb ending in an epigeal neck, covered by whitish transversally banded membranous cataphylls, giving a conspicuous zebra banding pattern ( Fig. 5). Moreover, its erect and helicoidal raceme with white and green erect flowers, and the smaller seeds (c. 4-5 × 3-4 mm), separate it from Albuca caudata .

Etymology.

Name honouring John Gilbert Baker (1834-1920), a leading expert on monocotyledons, who worked at the Royal Botanic Gardens, Kew, and was the keeper of the herbarium K.

Relationships.

No other Albuca with erect flowers have been described with the characteristic long, thin, zebra banded bulb neck of Albuca bakeri . The closest species appears to be Albuca caudata , though the structure of the bulb and inflorescence clearly distinguish them ( Table 1 ).

Observations.

The peculiar zebra banded cataphylls of Albuca bakeri are similar to those found in some other groups of Hyacinthaceae . As pointed out by Müller-Doblies and Müller-Doblies (1981), zebrine cataphylls are present in evolutive distant taxa such as Rhadamanthus fasciatus B. Nord., Tenicroa exuviata (Jacq.) Speta ( Urgineoideae ), several species of Ledebouria Roth ( Scilloideae ), Coilonox zebrinum (Baker) Speta and some species of Nicipe Raf. [= Ornithogalum sect. Vaginaspasia U. Müll.-Doblies & amp; D. Müll.-Doblies] ( Ornithogaloideae ). Moreover, Stellarioides arida (Oberm.) Speta and Battandiera stapffii (Schinz) Mart.- Azorín, M.B.Crespo & Juan show the neck of the bulb covered with membranose transversally banded cathaphylls, indicating that the zebrine cataphylls could have evolved independently in at least five lineages of the Ornithogaloideae (e.g. Albuca , Battandiera , Coilonox , Nicipe and Stellarioides ), possibly as a result of convergent evolution in dry climates of southern Africa.

Some morphological variation has been found within Albuca bakeri . Some individuals from Janseville and Port Elizabeth have a slightly setose bulb neck with the characteristic transversally banded membranous cataphylls of this species. Other specimens from Grahamstown and Port Elizabeth showed somewhat proliferous bulbs, resulting in a small clump of plants growing together, and with shorter scales not so markedly banded.

When Baker (1897) described and illustrated his concept of Albuca caudata ( Fig. 2), he mentioned: "Bulb two to three inches thick, round or oblong, crowned as in the preceding [ Albuca fastigiata Dryand.] with brown fibres. Leaves about a foot long, four lines broad, more rigid than in the preceding, clasping the stem at the base and more or less concave on the face upwards, and keeled on the back". This description is vague and inaccurate, since the illustration he presented did not show "fibres" at all, and no specific comments on the transversal banding of the upper scales of the bulb were made. However, when Baker reconsidered Albuca caudata in later works, his previous concept was changed to "Bulbus globosus 2-3 poll. crassus viridis apice squamosus" ( Baker 1872), or "bulb globose, 2-3 in. diam.; tunics not splitting into fibres at the top" ( Baker 1897), or "Bulb globose, 2-3 in. diam." ( Baker 1898).

Materials studied.

SOUTH AFRICA. Eastern Cape, Alexandria, 1½ miles east of Paterson, 1000 feet, 24.VIII.1953, E.E.A. Archibald 5972 (GRA); Eastern Cape, Alexandria, south-west end of Zuurkop, Addo National Park, 1000 feet, 23.IX.1953, S.M. Johnson 751 (GRA); Eastern Cape, Albany, 5 miles north of Alicedale, on Riebeck East road, 1500 feet, 21.IX.1954, E.E.A. Archibald 5638 (GRA); Victoria East: Alice, dry stony places on Sandilis Kop on north east side, 08.IX.1934, M.H. Giffen 614 (GRA); Victoria East: Alice, Sandilis Kop western side among grass, 13.IX.1935, M.H. Giffen 618 (GRA); Hillside, Gowie´s Kloof, Grahamstown, IX.1947, Hill s.n. (GRA); Grahamstown, West Hill, Pine plantation, VIII.1956, V. van Niekerk s.n. (GRA); Cradock road, Grahamstown, 01.IX.1945, E. Barrat 28 (GRA); In graminosis prope Grahamstown, M. Daly & M. Sole 316 (BOL); In graminosis prope Grahamstown, 2000 feet, VIII.1893, Schonland s.n. (NBG); Grahamstown (3326 BC): Ecca Reserve, south near old Queens Road/Quarry, 20.VIII.1992, T. Dold 153 (GRA); Leander Beacon, VIII.1943, L. Miles s.n. (GRA); Port Elizabeth, Summerstrand, grassy roadside, IX-X.1990, H.J. Vanderplank s.n. (GRA); Port Elizabeth (3325CD): 3 km south of Uitenhage towards van Stadens, 01.IV.1978, P.L. Perry 601 (NBG); Port Elizabeth (3325CB): Kirkwood District, farm Brakleegte, 300 m, 28.VIII.1985, M.T. Hoffman 1064, 1065 (NBG); ibidem, 14.IX.1985, M.T. Hoffman 1002 (NBG); Graaff-Reinet (3224DC): District Janseville, just south of Janseville (+/- 1 km) in municipal-owned land, 11.VIII.1985, M.T. Hoffman 1063 (NBG); Ladismith (3321BC): Calitzdorp dam, 22.II.1981, P.L. Perry 1521 (NBG); Ladismith (3321CC): Sopieshoogte, north entrance to Garcia´s Pass, Riversdale, 1600 feet, 15.IX.1981, Albuca Fellingham 149 (NBG); Eastern Cape, Grahamstown, hills above Botanic Garden, 591 m, 14.XI.2009, 33°19'04"S, 26°31'15"E, M. Martínez-Azorín & A. Martínez-Soler 12 (GRA); Eastern Cape, Grahamstown, Burnkraal, 649 m, 24.XI.2009, 33°16'40"S, 26°29'41"E, M. Martínez-Azorín & A.P. Dold 34 (GRA); Eastern Cape, Redhouse, thicket west of village, 6 m, 27.XI.2009, 33°50'01"S, 25°33'56"E, M. Martínez-Azorín, A.P. Dold & A. Martínez-Soler 44 (GRA); Eastern Cape, north of Grahamstown, Table Hill farm, 587 m, 11.XII.2009, 33°15'21"S, 26°27'17"E, M. Martínez-Azorín & A.P. Dold 83 (GRA); Eastern Cape, north of Grahamstown, on Cradock road turn off to Kwandwe, 594 m, 31.I.2010, 33°12'38"S, 26°24'07"E, M. Martínez-Azorín, M.B. Crespo & A. Martínez-Soler 118 (GRA); Eastern Cape, Quamnyana, between Breakfast Vlei and Commitees Drift, 411 m, 14.VIII.2010, 33°06'56"S, 22°55'57"E, C. Peter (GRA); ibidem, 27.VIII.2010, M. Martínez-Azorín & A.P. Dold 207 (GRA); Eastern Cape, Port Elizabeth, Settler´s Park, 28 m, 03.IX.2010, 33°58'21"S, 25°36'09"E, M. Martínez-Azorín & A.P. Dold 210 (GRA); Eastern Cape, Grahamstown, Sunny side, Hillsview street, 570 m, 07.IX.2010, 33°19'08"S, 26°32'00"E, M. Martínez-Azorín & A. Martínez-Soler 221 (GRA); Eastern Cape, Alicedale, railway cross to Burchell Game Reserve, 288 m, 14.IX.2010, 33°18'51"S, 26°06'01"E, M. Martínez-Azorín & A. Martínez-Soler 226 (GRA); Eastern Cape, Alice, Fort Hare University, Sandili's Kop, 582 m, 17.IX.2010, 32°47'02"S, 26°51'38"E, M. Martínez-Azorín & A. Martínez-Soler 235 (GRA); Eastern Cape, Keiskamma River, Linedrift, 141 m, 12.XI.2010, 33°04'29"S, 27°13'02"E, M. Martínez-Azorín, A.P. Dold & A. Martínez-Soler 525 (GRA).