Cynoglossum spelaeum Hilliard & B.L.Burtt

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 : 37-39

8. Cynoglossum spelaeum Hilliard & B.L.Burtt in Notes Roy. Bot. Gard., Edinburgh 37(2): 287 (1979).

Cynoglossum basuticum Weim.ex Guillarmod , Fl. Lesotho 233 (1973), nom. nud.

Type. South Africa ♀ ♂, KwaZulu-Natal, Underberg (2929): Underberg District, Cobham Forest Station , Polela valley (-CD), 20 Mar 1977, O.M. Hilliard and B.L. Burtt 9728 ( E, holotype image! K-image!, NU-image! PRE-image! [2 sheets] isotype) .

Perennial herbs, ca. 0.4–0.5 m in height. Basal leaves 130–235× 25–35 mm, spathulate-obtuse, soft hairs, deciduous, margins entire. Stem leaves 40–80× 10–25 mm, obtuse shaped, dark green adaxial surface, grey green abaxial surface, smooth margins, soft hairs, sparsely packed. Trichomes unicellular, simple on both leaf surfaces, soft. Inflorescence corymbose panicle; threadlike pedicel 5 mm long. Calyx ca. 1.5–2.0 mm long, lobes lanceolate-oblong, softly hairy on the outer surface, inner surface smooth, apex acute. Corolla white; lobes ca. 3× 3 mm diameter, obtuse. Nutlets ovoid, ca. 4× 5 mm; glochidia more marginal and acentric, marginal glochidia are longer compared to the acentric glochidia ( Figure 17).

Phenology. December to March.

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

Diagnostic characters. This species is characterised by leaves that are sparsely covered with hairs that have a softer feel, which distinguishes it sharply from all the other southern African species which have either brittle or woolly hairs. The abaxial leaf surface has a grey-greenish appearance which is also a unique character of this species.

Distribution and habitat. The species is distributed in South Africa (Eastern Cape, Free-State, and KwaZulu-Natal Provinces) and Lesotho ( Figure 18). It grows in loose sandy soil at the edge of an overhang.

Additional specimens examined. South Africa. KWAZULU-NATAL: 2729 (Utrecht): Ncandu State Forest (- DC), 8 May 1984, A. Nicholas and B. Isaacs 1965 ( PRE). 2929 (Underberg): Allandale, Lion’s River District (- BC), 24 Jan 1978, O.M. Hilliard and B.L. Burtt 11258 ( NU); Giant’s Castle Nature Reserve (- BC), 07 Jan 1988, A. Abbott 4064 ( NH); 3 Feb 1976, O.M. Hilliard and B.L. Burtt 8904 ( NU); 2 Jan 1978, O.M. Hilliard and B.L. Burtt 11172 ( NU); 20 Nov 1985, O.M. Hilliard and B.L. Burtt 18242 ( NU, PRE); Bulwer District (- DD), 8 Jan 1974, M.A. Rennie 507 ( NU); 8 Mar 2019, A.N. Moteetee and L.K. Madika AL012 ( JRAU). EASTERN CAPE: 3127 (Lady Frere): Elliot District (- BB), 22 Jan 1979, O.M. Hilliard and B.L. Burtt 123427 ( NU). 3226 (Fort Beaufort): Amatole Mountain (- DB), 16 Feb 1986, P.B. Phillipson 1294 ( PRE).

Lesotho. 2927 (Maseru): Laikopile Mountain (- CD), Jan 1918, A. Dieterlen 40799 ( PRE).

Taxonomic notes. Cynoglossum spelaeum is quite distinctive among the southern African species having uniquely shaped (i.e., spatulate to obtuse) and coloured (i.e., deep green adaxial surface, grey green abaxial surface) leaves, that almost seem leathery but contain few soft trichomes. It is also the only species among the southern African species that has completely white flowers. Although Hilger et al. (2015) indicated that the species does not belong to genus Cynoglossum , they did not elaborate the reasons for the exclusion. Nonetheless, the species fits the generic description of four glochidiate nutlets that are adapted for zoochory. In addition, preliminary molecular data ( Madika 2020), showed a close relationship between C. coeruleum subsp. johnstonii var. mannii , C. lanceolatum , and C. spelaeum .