Peliostomum E.Mey. ex Benth.

Kolberg H., van Salgeren M. 2016. A synopsis of Aptosimum and Peliostomum (Scrophulariaceae) in Namibia, including the description of a new species, Aptosimum radiatum, and keys to all accepted species. Kew Bulletin 71:16. DOI 10.1007/S12225-016-9628-7

Morphology General Habit

Perennial, low shrubs

Morphology Leaves

Leaves alternate, crowded or scattered, linear, elongate, elliptical, ovate or obovate, sessile to shortly petiolate, entire, 1-veined, subglabrous, densely or sparsely papillose, finely glandular-tomentose to viscid

Morphology Reproductive morphology Flowers

Flowers solitary in leaf axils, very shortly pedicellate with 2 small bracteoles at base, dark blue to violet

Morphology Reproductive morphology Flowers Androecium Stamens

Stamens 4, didynamous, included, arising in lower part of corolla tube; filaments filiform, one pair longer than other; anthers of equal size, all fertile, dorsifixed, usually ciliate-hispid, rarely glabrous; thecae confluent, dehiscing along a single transverse line

Morphology Reproductive morphology Flowers Calyx

Calyx divided almost to base, 5-lobed, more or less valvate; lobes linear, narrow, acute

Morphology Reproductive morphology Flowers Corolla

Corolla tubular, weakly zygomorphic, 5-lobed, much longer than calyx; tube elongated, narrow below, widening into long throat, mouth wide; lobes about equal, free, rounded, spreading, shorter than tube, posterior pair outside in bud

Morphology Reproductive morphology Flowers Gynoecium Ovary

Ovary bilocular, narrowly ovoid; ovules many; style filiform, exceeding stamens; stigma small entire, emarginate or very slightly bilobed

Morphology Reproductive morphology Fruits

Capsule thin-walled, longer than calyx, narrowly elongate-ovoid, acute, acuminate or obtusely pointed, somewhat compressed at right angles to septum, bisulcate over septum, septicidally bivalved, opening more or less to base; valves deeply bilobed

Morphology Reproductive morphology Seeds

Seeds numerous, rugose or scrobiculate-tuberculate, cream-coloured to brownish.

Morphology Stem

Stems slender, usually erect, longitudinally striated, glabrous to subglabrous, sometimes viscid, woody at base, sometimes dying-back to base; bark corky at transition to root

Note

No type had thus far been assigned for Peliostomum (Farr & Zijlstra 2014). Bentham (1836) described the genus and five species, P. scoparium, P. leucorrhizum, P. viscosum, P. virgatum and P. origanoides, of which P. scoparium is now considered to belong to Anticharis. He attributed the names to E. Meyer and cited specimens collected by J. F. Drège in South Africa for all of the species. For P. virgatum, he also cited a specimen collected by C. F. Ecklon. P. virgatum is here designated as the type because it is the most recognisable and least variable species of those described by Bentham in 1836.

Type

Type: Peliostomum virgatum E. Mey. ex Benth., here designated — see Notes.