Lebeckia ambigua, E. Mey.

le Roux, M. M. & Van Wyk, B. - E., 2007, A revision of Lebeckia sect. Lebeckia: The L. sepiaria group, South African Journal of Botany 73 (1), pp. 118-130 : 122-124

4.1. L. ambigua

L. ambigua E. Mey., Comm. Pl. Afr. Austr. 1: 34 (1836), pro parte majore; Benth. in Hook., Lond. J. Bot. 3: 357 (1844); Harv. in Harv and Sond., Fl. Cap. 2: 86 (1862); Goldblatt and Manning, Cape Plants, Strelitzia 9: 493 (2000).

Type: South Africa, “Uienvalley” [near Clanwilliam, 3218 BB], Drège s.n. (“ III, A, c”) ( P!, the specimen on the right hand side of the sheet, lectotype designated here; S!, isosyntype) and Saldanha Bay [3318 AA], Drège s.n. (“ III, E, b”), ( P! isosyntype).

Erect, glaucous suffrutex, up to 0.8 m in height. Leaves simple, acicular, articulated near the middle; leaf density 2–5 per 10 mm length of stem. Inflorescences terminal, 90–350 mm long; rachis smooth; flowers numerous, relatively sparse (3–5 per 10 mm length of rachis), intermediate in size (7–10 mm long); pedicel 2– 3 mm long; bract narrowly lanceolate, acuminate, 2.0– 3.5 mm long; bracteoles narrowly triangular, acuminate, ± 1 mm long. Calyx 3.5–5 mm long, tube 1.5–2.5 mm long, lobes 1.5–2.5 mm long; subequally lobed but the upper lateral sinuses much wider than the medial sinus and the lower lateral sinuses; lobes deltoid, tips minutely pubescent inside. Standard widely ovate to orbicular, 8–10 × 4.5–8.0 mm; apex obtuse; claw 1–2 mm long. Wings oblong, as long as or usually longer than the keel, 7–9 × 2.0– 3.5 mm, with 9–12 rows of sculpturing; apex obtuse; claws 1.5–2.5 mm long. Keel rostrate, 6.0–8.5× 2.5– 3.5 mm, usually with pockets; claws 1.5–3.0 mm long. Pistil subsessile; ovary 5.5–11.0 × ± 0.5 mm long, linear; ovules many (14–18); style 2.5–3.5 mm long, curved upwards. Pods narrowly linear, straight or falcate, up to 75 × 2 mm; dehiscent; terete; fruit wall thin, membranous. Seeds oblong-reniform, 2.0 × 1.2 mm, rugose, light pink; hilum black ( Fig. 5 ).

4.1.1. Diagnostic characters

L. ambigua is closely related to L. sepiaria but differs in the membranous, narrowly linear, straight or falcate, ± 2 mm wide, dehiscent fruit ( L. sepiaria has spongy, linear, straight, ± 4 mm wide and indehiscent fruit) and smaller flowers (7–10 mm long) (12–18 mm long in L. sepiaria ) ( Fig. 5 ).

4.1.2. Distribution and habitat

L. ambigua occurs in the low-lying coastal region of the Northern and Western Cape Provinces, from Namaqualand southwards to a little north of Cape Town ( Fig. 6 ). The altitude is usually below 300 m but may be up to 900 m at some localities. Plants grow in deep sandy soil, usually in obviously disturbed areas such as riverbanks and roadsides.

4.1.3. Specimens examined

– 2917 (Namaqualand): Namaqualand (– CD), Le Roux 374 ( NBG).

– 3017 (Kamieskroon): Kotzerus (– DD), Acocks 23398 ( PRE).

– 3117 (Vredendal): Lepelfontein (– BB), Helme 2930 ( NBG).

– 3118 (Van Rhynsdorp): 23 miles from Clanwilliam (– DA), Grobbelaar 1129 ( PRE) ; Van Rhynsdorp (– DA) , Marloth 2627 ( PRE) , Rossouw 18619 ( NBG) ; near turn-off to Klawer on the N7 (– DA), Van Wyk 3120 ( JRAU) ; foot of Gifberg (– DB), Zietsman 1180 ( PRE) ; foot of Heerelogementsberg near Klawer (– DC), Van Wyk 3284 ( JRAU) ; Klawer (– DC) , Barker 3637 ( NBG) , Lewis 1309 ( SAM) ; De Little Farm, Nardouwsberg (– DD), Stirton 9365 ( PRE) .

– 3119 (Calvinia): Arendskraal Farm , near Nieuwoudtville (– AC) , Barker 9781 ( NBG) ; Lokenburg House (– CA), Acocks 18568 ( PRE) ; top of Botterkloof (– CD), Barker 6515 ( NBG) .

– 3218 (Clanwilliam): Wadrif, Soutpan , coastal side of the railway (– AB), O̕Ca llanghan, Van Wyk and Morley 90 ( PRE) ; Lambert̕s Bay (– AB), Henrici 3297 ( PRE) ; farm Wolfhuis (– AB), Stirton 9294, 9388 ( PRE) ; Uitkomsberge, Bo-Voëlfontein Farm (– AB), Stirton 9351 ( PRE) ; Nortier station (– AB), Van Breda 4460 ( PRE); Verlore Vlei (– AD), Stirton 6100 ( PRE); between Elandsvlei and Redelinghuys (– AD), Stirton 6117 ( PRE); between Leipoldtville and Elands Bay (– AD), Zinn s.n. ( SAM); between Lambert̕s Bay and Clanwilliam (– BA), Marsh 781 ( NBG); Graaffwater (– BA), Van Breda 4363 ( PRE); Clanwilliam Park (– BB), Acocks 15179 ( PRE); Olifants River Bridge (– BB), De Winter 9564 ( PRE); Clanwilliam (– BB), Leipoldt 349 ( SAM), Repton 7176 ( PRE), Van Wyk 2605 ( PRE); between Clanwilliam and Springbok (– BB), Le Roux 2625 ( BOL); north of Clanwilliam (– BB), Le Roux, Boatwright, Magee and Van Wyk 6 ( JRAU); Redelinghuys, Piketberg (– BC), Acocks 19795 ( PRE), Compton 15052 ( NBG); Paleisheuwel (– BC), Stirton 9294 ( PRE); Berg River (– CC), Ecklon and Zeyher 1334 ( SAM); Berg River Station, Malmesbury (– CD), Compton 15103 ( NBG); Paleisheuwel (– CD), Stirton 9294 ( PRE); Berg River Valley (– DA), Acock 2930 ( S); Paleisheuwel Station, north of Het Kruis (– DA), Wisura 3486 ( NBG); 3 miles from Grey̕s Pass , Piketberg (– DB), Barker 6406 ( NBG); between Piketberg and Grey̕s Pass (– DB), Lewis 3391 ( SAM); between Piketberg and Citrusdal (– DB), Parker 3588 ( NBG); Citrusdal (– DB), Niemand 11 ( JRAU); between Pakhuis Pass and Piquetberg (– DB), Parker 61 ( BOL); between Citrusdal and Clanwilliam (– DB), Van Wyk 2900 ( JRAU); Piekenierskloof Pass (– DB), Van Wyk 3220 ( JRAU); Olifantsrivier (– DC), Grobbelaar 1129 ( PRE); Piketberg (– DC), Heyns 26146 ( NBG); Sauer (– DC), Acocks 24459 ( PRE); Piketberg (– DD), Van Breda 352 ( PRE).

– 3219 (Wuppertal): Cedarberg, Boesmanskloof , Wuppertal (– AA), Van Rooyen, Steyn and De Villiers 499 ( NBG) ; Cedarberg, Wuppertal (– AC), Bolus 8972 ( NBG) ; Warm Baths (– CA), Le Roux , Boatwright , Magee and Van Wyk 9 ( JRAU) .

– 3318 (Cape Town): Langebaan , Schrywershoek (– AA), Boucher 2946e ( NBG) ; Langebaan (– AA), Cupido 13 ( NBG) ; Langebaan, behind the granite koppie (– AA), Goldblatt 2704 ( PRE) ; Saldanha Bay, Langebaan (– AA), Taylor 3757 ( NBG) ; Darling near Ysterfontein (– AA), Van Rensburg 157 ( NBG, PRE) ; 125 km north of Cape Town on the R27 (– AA), Van Wyk 3290 ( JRAU) ; Hopefield (– AB), Acocks 20669 ( PRE) , Bolus 12653 ( PRE) ; Modderriver (– AD) , Le Roux, Boatwright , Magee and Van Wyk 14 ( JRAU) ; in fields near Hopefield (– DC) , Letty 35 ( PRE) .

Figures

Fig. 5. Morphology of Lebeckia ambigua: (a) lateral view of flower; (b) abaxial view of bract and bracteoles; (c) abaxial view of calyx with the upper lobes to the left; (d) standard petal; (e) wing petal; (f) keel petal; (g) anthers; (h) long, basifixed anther, carinal (intermediate) anther and short, dorsifixed anther; (i) pistil; (j1 – j3) lateral view of pods; (k) cross section of pod; (l) leaf. Vouchers: (a, l) from Barker 9781 (NBG); (b) from Rossouw 18619 (NBG); (c) from Barker 9781 (NBG); (d, i) from O̕Callaghan, Van Wyk and Morley 90 (NBG); (e, f) from Boucher 2946e (NBG); (g, j3, h) from Le Roux 374 (NBG); (j1) from Heyns 1942 (NBG); (j2) from Niemand 11 (JRAU); (k) from Le Roux, Boatwright, Magee and Van Wyk 6 (JRAU). Scale bars: 1 mm.

Fig. 6. Known distribution of Lebeckia ambigua.