Lachenalia inflata 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 : 265-266

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

Type: — SOUTH AFRICA. Northern Cape: Akkerendam Nature Reserve, Calvinia (3119 BD), stony clay flats and lower slopes of Hantamsberg Mountains , among low scrub, elev. 1139 m, 22 July 1961, Barker 9319 (holotype NBG!) .

This new species differs from L. mutabilis Loddiges ex Schultes & Schultes in Linnaeus (1830: 1710) in having a bright yellow perianth with the upper two inner tepals equal in length to the lower inner tepal, and in its shorter filaments and oblong, narrower seeds with an inflated raphe.

Deciduous, winter-green geophyte 80–220 mm high. Bulb subglobose, 15–22 mm in diam., solitary; tunic multilayered, outer tunics spongy, dark brown, inner tunics membranous, translucent light brown; cataphyll translucent white, apex obtuse. Leaf 1, rarely 2, lanceolate, 100–150 × 10–20 mm, suberect, conduplicate, leathery, upper and lower surfaces green or glaucous, sometimes heavily flushed with brownish purple, or heavily purple- or greenblotched along median; margins thickened/cartilaginous, slightly to strongly undulate, sometimes crisped; leaf bases clasping, 10–20 mm long, light green, sporadically or densely marked with purplish or green botches on outer surface; primary seedling leaf prostrate, flat. Inflorescence spicate, 10–35-flowered; peduncle erect or suberect, moderately or strongly inflated above, maroon, or dull mauve-flushed in upper half, light green and mauve-spotted in lower half; rachis inflated and mauve-flushed in lower half, shading to brownish green in upper half; sterile apex 10–20 mm long, light green or light mauve; lower bracts cup-shaped, 1 × 2 mm, translucent white, upper bracts lanceolate, 2–5 × 1 mm, translucent white. Perianth zygomorphic, urceolate, slightly cernuous; perianth tube cup-shaped, 2–3 mm long, light greenish yellow or bright yellow; outer tepals ovate, 6–7 × 4 mm, bright yellow or greenish yellow, apices straight, apical gibbosity dark yellow, brown or brownish green; inner tepals obovate, 7–9 × 3–4 mm, bright yellow or greenish yellow, apices slightly recurved, median keel dull brown or brownish green. Stamens declinate, included; filaments 5–6 mm long, white. Ovary ellipsoid, 4 × 2 mm, light green; style declinate, included, 5 mm long, white, stigma minutely capitate. Capsule ellipsoid, 8–9 × 4–5 mm. Seed oblong, 1.2 × 0.9 mm, glossy, smooth, black; strophiole 0.7 mm long, glossy, inflated, smooth; raphe inflated. Flowering time: July to September.

Etymology:— The specific epithet inflata is descriptive of the inflated upper part of the peduncle.

Other material examined:— SOUTH AFRICA. Northern Cape: 12 km west of Calvinia on R355 to Loeriesfontein (3119 BC) , on red, sandy clay flats, among low scrub, 4 September 2007, Harrower 3594 ( NBG, photo); Akkerendam Nature Reserve, Calvinia (3119 BD) , stony clay flats below Hantam Mountains, among low scrub, 26 August 2007, Avenant s.n. ( NBG, photo); Farm Hangnes, Leliekrantz Road NW of Middelpos (3120 CC) , scattered solitary plants on flats among low scrub, in deep red sand, in full sun or light shade of bushes, elev. 1189 m, 24 September 2015, Duncan 666 ( NBG) .

Notes:— The first collection of L. inflata was made by W.F. Barker within the Akkerendam Nature Reserve at the base of the Hantam Mountains at Calvinia on 22 July 1961. On 22 September 2006, G.C. Summerfield recorded it on the farm Hangnes northwest of Middelpos in the Roggeveld, and he was the first to note that the oblong seeds of this species differed markedly from the globose ones of L. mutabilis , and thus suspected it to represent an undescribed species. In August 2007, F. Avenant photographed it in flower at Akkerendam Nature Reserve, and in September 2007, A.D. Harrower recorded it in flower just west of Calvinia. During a visit to Hangnes on 24 September 2015, the plant was sampled and studied in habitat by G.D. Duncan.

Diagnostic features and affinities:— Lachenalia inflata is recognised in flower by an erect or suberect spike of urceolate, bright yellow or greenish yellow, slightly cernuous flowers carried on a strongly inflated, maroon, or dull mauve-flushed peduncle which is marked with purple or maroon blotches ( Fig. 1 D, E ). It has shallowly cup-shaped perianth tubes, the outer tepals have a dark yellow, brown or greenish brown apical gibbosity, and the protruding inner tepals have a dark yellow, dull brown or brownish green median keel. The flowers have included, declinate stamens, and bracts that are cup-shaped at the base of the inflorescence and lanceolate above. The plant usually has a solitary leathery lanceolate leaf (rarely 2) which is conduplicate or deeply channelled, and the margins are thickened/ cartilaginous and slightly to strongly undulate or sometimes crisped. The ripe fruit is an ellipsoid capsule containing oblong, glossy black seeds with a smooth, black strophiole and an inflated raphe.

Lachenalia inflata is included within subsect. Oncoraphae of sect. Lachenalia ( Duncan et al. 2022) . It was initially considered to be merely a yellow-flowered form of L. mutabilis , but in phylogenetic analysis it was retrieved as sister to the sister pair L. bulbifera ( Cirillo 1788: 35) Engler (1899: 321) and L. punctata Jacquin (1789: 323) , two widespread, long-tubed, tubular-flowered lachenalias mainly from coastal parts of the Western and Northern Cape. These three taxa constitute the only members of subsect. Oncoraphae and are united by the possession of seeds with an inflated raphe ( Duncan et al. 2022). L. mutabilis differs from L. inflata in having a light blue perianth tube, greenishbrown, light to deep mauve outer tepals with prominent brown apical gibbosities, and inner tepals that are yellowishgreen or translucent white, with brown or green median keels, with the lower inner tepal slightly longer than the upper inner tepals. It differs further in having longer filaments 7–9 mm long (versus 5–6 mm long), globose seeds (versus oblong) with a longer length range of 1.2–1.4 mm (versus 1.2 mm) and are wider (1.3–1.4 mm, versus 0.9 mm), and have no inflated raphe.

Distribution and habitat:— Lachenalia inflata occurs within the Succulent Karoo Biome and is currently known from only three locations ( Fig. 2 ). It frequents dwarf shrubland in Hantam Karoo vegetation on stony red clay flats and lower slopes of the Hantamsberg within the Akkerendam Nature Reserve at Calvinia, as well as on clay flats to the west of this town, whereas to the northwest of Middelpos (southeast of Calvinia), it occurs in Roggeveld Karoo vegetation in deep red sand ( Mucina & Rutherford 2006) ( Fig. 1 F ). Plants occur as scattered solitary individuals or in groups of two, in open aspects or within the protection of low karroid scrub, and flowering takes place from late winter to spring (late July 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).