Cynoglossum obtusicalyx Retief & A.E. van Wyk

Madika, Lydia K. & Moteetee, Annah Ntsamaeeng, 2022, Taxonomic revision of the southern African species of the genus Cynoglossum L. (Boraginaceae), PhytoKeys 193, pp. 9-42 : 35-36

7. Cynoglossum obtusicalyx Retief & A.E. van Wyk in S. Afr. J. Bot. 62(3): 169– 172 (1996).

Type. South Africa ♀ ♂, Western Cape, Worcester (3319): 20 km E. of Ceres (-AD), 21 Oct 1958, Acocks 19893 ( PRE-image! holotype; NBG, isotype) .

Perennial or biennial herbs, ca. 0.45 m in height. Basal leaves 175–250× 5–18 mm, obtuse, densely pubescent, persistent, margins entire. Stem leaves 50–65× 5–10 mm, obtuse-lanceolate, apex acute, base cuneate, soft hairs. Trichomes woolly, soft, nonbulbous based, unicellular, long, thin. Inflorescence dichotomously branched terminal cymes, pedicel 5–10 mm long, lengthens considerably in fruit. Calyx ca.1.0– 1.6 mm long, lobe oblong, densely pubescent, apices broadly obtuse-truncate shaped. Corolla pale blue; lobes 5× 7 mm diameter, ovate. Nutlets ovoid-convex, 2–4× 3–4 mm, densely echinulate with glochidia ( Figure 15).

Diagnostic characters. The stems and leaves of Cynoglossum obtusicalyx are densely covered with soft, woolly trichomes which makes it similar to Cynoglossum alticola . However, the two species differ in flower colour and size (deep blue corolla, 4× 3 mm vs. pale blue corolla, 5× 7 mm in C. obtusicalyx ). Cynoglossum obtusicalyx has pale blue flowers with corolla 5–7 mm long whereas C. austroafricanum has bright blue flowers with corolla 2.75–4.25 mm long. The two species also show variation in trichome texture and density, i.e., sparsely hairy with short, stiff hairs on both the stem and leaves in C. austroafricanum vs. densely arranged long, woolly hair on both the stem and leaves in C. obtusicalyx .

Phenology. October to February.

Conservation status. Least Concern ( Raimondo et al. 2009).

Distribution and habitat. Cynoglossum obtusicalyx is endemic to South Africa where it has been recorded from Calvinia, Worcester, and Beaufort West in the Northern and Western Cape Provinces ( Figure 16), it occurs in mountainous areas, often growing on screes below cliffs.

Additional specimens examined. South Africa. NORTHERN CAPE: 3119 (Calvinia): Calvinia District (-BD), 22 Sep 1955, J.P.H. Acocks 8509 ( PRE); 22 Sep 1955, D.A Leistner 394 ( PRE; NBG). WESTERN CAPE: 3222 (Beaufort West): Mountain View farm (-BD), 17 Apr 1978, G. Gibbs Russell and R. Hermann 4272 ( PRE) .