Lachenalia filamentosa G.D.Duncan, 2023

Duncan, Graham D., 2023, Four new species and three taxonomic adjustments in Lachenalia (Asparagaceae: Scilloideae) from southern and western South Africa, Phytotaxa 585 (4), pp. 261-273 : 267-268

Lachenalia filamentosa G.D.Duncan , sp. nov. ( Figs. 1 , 2 )

Type: — SOUTH AFRICA. Western Cape: Die Poort, 5 miles [8 km] south of Bredasdorp (3420 CA), in [limestone] sand, elev. 84 m, 3 September 1943, Barker 2500 (holotype NBG!) .

This new species differs from L. contaminata Aiton (1789: 460) in having well-exserted stamens (8–11 mm long), longer outer tepals (6–7 mm long), longer inner tepals (7–8 mm long) and a larger globose seed (1.1–1.2 × 1.0 mm).

Deciduous, winter-green geophyte 110–150 mm high. Bulb subglobose, 15–20 mm in diam., offset-forming (1–3 offsets formed per bulb, but not necessarily every year); tunic multi-layered, outer tunics spongy, dark brown, inner tunics membranous, light brown; cataphyll translucent white, not adhering to leaf bases, apex obtuse. Leaves 3–6, linear, 120–155 × 1.5–5.0 mm, fleshy, glaucous-green, upper surface shallowly channelled in lower half, terete in upper half, lower surface glaucous-green or maroon-flushed, apices acute; primary seedling leaf erect, terete. Inflorescence racemose, 8–30-flowered; peduncle erect or suberect, light green, plain or purple-blotched in lower third, shading to dull maroon above; pedicels 2–3 mm long, suberect in flower, white or light magenta, becoming erect in fruit; bracts cup-shaped, green at base of inflorescence, shading to white above, 1–3 × 1–4 mm; perianth narrowly campanulate, suberect, spice-scented. Perianth tube cup-shaped, 2 mm long, white; outer tepals narrowly ovate, 6–7 × 3–4 mm, white, apical gibbosity narrow or prominent, magenta, median keel narrow or broad, magenta; inner tepals narrowly obovate, 7–8 × 3–4 mm, protruding 1 mm beyond outer tepals, white, median keel narrow or broad, magenta. Stamens well exserted, narrowly spreading; filaments white, inserted at distinctly different levels; filaments at base of outer tepals 8–9 mm long, filaments at base of inner tepals 10–11 mm long; anthers oblong, 1 mm long, maroon prior to anthesis, pollen yellow. Ovary ellipsoid, 2.0 × 1.8 mm, dull green, style straight, 10–11 mm long, becoming well exserted 7–8 mm beyond tepals as ovary enlarges, stigma capitate. Capsule ellipsoid, 7–8 × 4–5 mm, suberect. Seeds globose, 1.1 × 1.0 mm, glossy, black; strophiole rudimentary, 0.2 mm long, ridged. Flowering time: August to September.

Etymology:— The specific epithet filamentosa refers to the thread-like, well-exserted filaments.

Other material examined:— SOUTH AFRICA. Western Cape: southeast of Ludrift Farm, near Lambert’s Bay , wetland adjacent to sandveld fynbos (3218 AB) , 27 September 2002, Low 7682 ( NBG) . Farm ‘ Uitkyk’ , 10 km N of Porterville, on clay-shale (3218 DD) , 24 September 2002, Helme 2754 ( NBG) . Citrusdal , 3 miles (5 km) north of town, 31 August 1938 (3219 CA) , Salter 7492 ( NBG) . Eensaamheid Nature Reserve, 10 km west of Paarl , in waterlogged shale (3318 DD) , 26 September 2002, Helme 2755, ( NBG) . Tulbagh, Voëlvlei Tortoise Reserve , in red-brown stony clay (3319 AC) , 5 October 1989, Solomon 100 ( NBG) ; Rawsonville , between old and new N1, on sandstone (3319 CB) , 27 August 2007, Helme 4937 ( NBG) . Farm Boesmansrivier at foot of Riviersonderend Mountains, in white Table Mountain Sandstone, in fruit (3419 BB) , 10 October 1979, Malan 117 ( NBG) ; between Heuningrug and Wiesduif , on limestone koppie (3419 DB) , 29August 1995, Paterson-Jones 573 ( NBG) . De Hoop Nature Reserve , behind Manager’s house, in limestone fynbos (3420 AD) , 4 December , 2007, Duncan, Pekeur & Bennett 3596 ( NBG) ; De Hoop Nature Reserve , in light brown loam (3420 AD) , 21 August 1984, Scott 450 ( NBG) ; De Hoop Nature Reserve , Melkkamer, in sand (3420 AD) , 20 September 1984, van Wyk 1963 ( NBG) ; Bredasorp (3420 CA) , 4 September 1929, Barnes s.n. ( BOL) ; Die Poort (3420 CA) , 3 August 1940, Compton 9006 ( NBG) ; Die Poort, 5 miles [8 km] south of Bredasdorp , on limestone (3420 CA) , 19 September 1962, Nordenstam 1504 ( NBG) .

Notes:— The earliest collections of L. filamentosa were made by P. Barnes near Bredasdorp on 4 September, 1929 (BOL), and T.M. Salter north of Citrusdal on 31 August, 1938 (NBG). The species has been recorded numerous times in the vicinity of Bredasdorp and the adjacent De Hoop Nature Reserve.

Diagnostic features and affinities:— Lachenalia filamentosa is recognised in flower by dense racemes of narrowly campanulate, suberect white flowers, the outer tepals with a narrow or prominent, magenta apical gibbosity, and the outer and protruding inner tepals with a narrow or broad, magenta median keel. The stamens are well-exserted and narrowly spreading, with prominent maroon unripe anthers, and yellow ripe pollen ( Fig. 1 J–L ). During the fruiting stage, the pedicels change orientation from suberect to erect ( Fig. 1 L ). The 3–6 linear leaves have acute apices and are terete in the upper half, and shallowly channelled and considerably wider (up to 5 mm wide) in the lower half.

Lachenalia filamentosa is a member of sect. Lachenalia , subsect. Angustae ( Duncan et al. 2022). It was previously considered to be merely a form of L. contaminata with well-exserted stamens ( Duncan 2012), however in phylogenetic analysis it was retrieved as sister to a typical form of L. contaminata , despite the fact that a different accession of a typical form of L. contaminata was retrieved in a phylogenetically isolated part of the ‘subsect. Angustae ’ clade ( Duncan et al. 2022). L. contaminata differs from L. filamentosa in having included stamens (5 mm long), shorter outer tepals (5 mm long), shorter inner tepals (6–7 mm long) and a smaller globose seed (0.9–1.0 × 0.8–0.9 mm).

Distribution and habitat:— Lachenalia filamentosa is fairly widely distributed in the western, southwestern and southern parts of the Western Cape, from De Hoop Nature Reserve in the south to Lambert’s Bay in the north ( Fig. 2 ). It traverses a range of habitats and vegetation types, including limestone flats and hills in De Hoop Limestone Fynbos ( Mucina & Rutherford 2006) ( Fig. 1 L ), sandstone mountain slopes in North Sonderend Sandstone Fynbos near Riviersonderend, and clay-shale flats and hills in Breede Shale Renosterveld near Tulbagh, and usually occurs in large colonies. Elevation ranges from 15 m on the south coast to 900 m in the northern foothills of the Riviersonderend Mountains. Flowering takes place from early to late spring (early August to late September).

Figures

FIGURE 1. Lachenalia komsbergensis: detail of three flowering racemes in cultivation (A); single plant flowering in beige alluvium, Komsberg Pass (B); general view of Central Mountain Shale Renosterveldhabitat, Komsberg Pass (C).Lachenalia inflata: single flowering plant in red sand north of Middelpos (D); single flowering plant in red clay west of Calvinia (E); general view of Roggeveld Karoo habitat north of Middelpos (F). Lachenalia granitica: detail of flowering spike in cultivation, with arrow showing a very long bract (G); flowering plant from Vredenburg in cultivation (H); spike of flowering and fruiting plant in Saldanha Granite Strandveld habitat near Vredenburg (I). Lachenalia filamentosa: flowering plants from Riviersonderend in cultivation (J); single flowering plant from De Hoop Nature Reserve in cultivation (K); two plants in early fruiting stage in De Hoop Limestone Fynbos habitat, De Hoop Nature Reserve (L). Photographs: A-D, F-K by Graham Duncan; E by Adam Harrower; L by David Gwynne-Evans.

FIGURE 2. Distribution of Lachenalia komsbergensis in the southern Great Karoo of the Northern Cape, South Africa (inverted black triangle), Lachenalia inflata in the western Great Karoo, Northern Cape, South Africa (black triangles), Lachenalia granitica along the Cape West Coast, Western Cape, South Africa (black squares) and Lachenalia filamentosa along the Cape West Coast, Breede River Valley and Overberg in the Western Cape, South Africa (black dots).