Crepidorhopalon mutinondoensis Eb.Fischer & I.Darbyshire, 2014

Fischer, Eberhard, Darbyshire, Iain & Bingham, Mike G., 2014, A new species of Crepidorhopalon (Linderniaceae) from the Mutinondo Wilderness, Zambia, Phytotaxa 181 (3), pp. 171-178 : 173-177

Crepidorhopalon mutinondoensis Eb.Fischer & I.Darbyshire sp. nov. ( Fig. 1 , 2 )

Type:— ZAMBIA, Northern Province, Mpika District, Mutinondo Wilderness Area , 1460 m, 12° 27’ S 31° 17’ E, 9 March 2005, Bingham 12899, (holotype K, isotype KOBL) .

Diagnosis: —The new species is related to Crepidorhopalon latibracteatus and C. parviflorus from which it differs in the glabrous calyx and bracts except for the minute hairs along the margins of each, and the smaller calyx and corolla. Crepidorhopalon mutindoensis differs from Crepidorhopalon symoensii in the entire bracts, and the long peduncle.

Description—Annual herb, roots up to 1–1.5 cm long. Stems erect, quadrangular, 11–17 cm long, simple or with 1-several ramifications, glabrous. Leaves sessile, basal leaves lanceolate or ovate, 9–17 × 4–10 mm, base rounded or obtuse, apex acute, with dentate margin usually comprising 2–3 pairs of teeth, stem leaves 7.5–11 × 2–6 mm, all leaves glabrous. Inflorescence terminal, racemose, capitate, borne on long leafless peduncles typically 6–10.5 cm long, capitulate bracteate, outer bracts broadly ovate or ovate-orbicular, 4.5–7.5 × 3–7.5 mm, acuminate or barely so, apex up to 1.5 mm long, margin entire, minutely ciliate, elsewhere glabrous, inner bracts (if present) narrower, 4–5 × 1.5–3 mm. Calyx 5-lobed, campanulate, 3.5–4.7 mm long, lobes 1.5–2 × 0.2–0.3 mm, recurved, margins minutely ciliate. Corolla up to 8.5–10.5 mm long, blue to violet, the distal portion of the lobes of the lower lip and the margin of the upper lip white, up to 7–8 mm long, always with a yellow mark on lower lip formed by club-shaped hairs on a multicellular base up to 0.3–0.4 mm long, shortly glandular-pubescent externally, limb strongly 2-lipped, upper lip bifid at apex, 3–4 × 1.5–2.5 mm, lower lip tripartite, 4–5.5 mm long, mid-lobe 2.2–3.5 × 2–2.8 mm, tube cylindric or narrowly campanulate, 5–6.5 mm long. Stamens 4, filaments of the abaxial pair 3–4 mm long, with basal rounded bosses covered by glandular hairs, with 0.7–1 mm long anthers, filaments of adaxial pair 1.2–1.5 mm long, with anthers 0.9–1.2 mm long. Ovary 1–1.5 × 0.8 mm, with straight, filiform style, 5 mm long, glabrous. Capsule ± 3 mm long, glabrous; seeds ± 0.45 × 0.35 mm, aulacospermous: broadly longitudinally ridged with fine transverse ridging..

Distribution:—Only known from the the Mutinondo Wilderness Area in northeast Zambia.

Ecology:—Growing in wet seepages at the foot of granite inselbergs and outcrops, where it is associated with a small annual herbaceous community.

Conservation status:—Two populations of this species have so far been found within the Mutinondo Wilderness area, both close to Mutinondo Lodge. At the first there is a c. 10 × 20m wet scree area at the foot of a granite inselberg, with three patches measuring approximately 1 m 2 dominated by over 40 of these plants each, with a less dense population scattered over the rest of the area. The second is in a wet area with a similar density of the Crepidorhopalon as the first but spreading over a larger area. A rough estimate would therefore place the known population of mature individuals at less than 1000, within the threshold to potentially qualify this species as Endangered under criterion C or Vulnerable under criterion D following the IUCN (2001) guidelines.

Mutinondo is a privately owned nature concession (see www.mutinondozambia.com). It covers c. 10,000 ha in total and has a number of granite inselbergs which may support further populations of this species. Since the site is protected (the main activity in this remote area being small-scale ecotourism), the populations are unlikely to be threatened by human influence and no other threats are known. The lack of an apparent threat disqualifies the application of IUCN criterion C and so this species is best assessed as VU D1 under IUCN (2001) at the present time, it being the very small and restricted population that renders it inherantly vulnerable to extinction. Future discoveries of further populations around some of the more remote granite inselbergs in the area would likely result in the downgrading of this threat status.

Additional specimens examined — ZAMBIA. Northern Province, Mpika District: Mutinondo Wilderness Area , base camp, 1476 m, 12º 27.157’ S 31º 17.329’ E, fr. 6 April 2003, C. Chishala & P. Smith 2 (K, Mutinondo) & P. Smith & C. Chishala 1822 (K); Mutinondo Wilderness, fr., April 2010, L. & M. Merrett s.n. (K) .

Figures

FIGURE 1. Crepidorhopalon mutinondoensis. A, habit; B, corolla; C–E, inflorescence; F, outer bract; G, inner bract; H, calyx; I, corolla, dissected; K, adaxial stamen; L, M, abaxial stamens; N, clavate hairs on lower lip of corolla. All from Bingham 12899. Drawing by E. Fischer.

FIGURE 2. Crepidorhopalon mutinondoensis. A, habit; B–D, inflorescence.All photos taken at the type locality by Charles Alford.