Low shrubs or perennial herbs up to 0.6 m tall, glabrous or leaves papillose, with stems caespitose or ± creeping and rooting, branching from taproot and (from stem) lateral and pseudodichotomous, woody at base, without condensed sterile basal or axillary shoots; dark (black or rarely red) glands confined to petal and usually sepal margin. Stems 3–4(5)-lined, eglandular. Leaves 3–4-whorled, decussate, petiolate, free, eventually deciduous below, coriaceous; lamina linear entire, 1-veined; laminar glands pale; intramarginal glands pale (usually hidden); ventral glands absent. Inflorescence 1–∞-flowered, with branching dichasial or monochasial, from 1–6 nodes, without or with subsidiary flowering branches from 1–2 nodes below; buds erect. Flowers stellate, homostylous. Sepals 5, equal, free, imbricate, persistent, erect in fruit, with margin regularly glandular-denticulate to -ciliate or glands sessile or absent; veins 3 ; laminar glands pale, linear to striiform; marginal glands black, globose, or absent. Petals 5, persistent or deciduous, not unguiculate, erect after flowering when persistent, without apiculus, not red-tinged or -veined; margin entire or with glandular cilia; laminar glands pale, punctiform or absent; marginal glands black, globose. Stamen fascicles ‘3’ (i.e. 2+2+1), persistent or deciduous, with stamens totalling 25–60, basally united in each fascicle; anther yellow, gland amber; pollen type X. Ovary with 3 axile placentae, each ∞-ovulate; styles 3, divergent from discrete bases; stigmas small. Capsule 3-valved, subcoriaceous to papyraceous, longitudinally vittate, sometimes also with lateral vittae or vesicles. Seeds cylindric or ± elongate, not or slightly carinate, not appendiculate or with terminal expansion; testa finely linear-foveolate (1. asperuloides) or rugulose to finely papillose.
BASIC CHROMOSOME NUMBER (X). 9; ploidy 2.
Calcareous rocks; 0–2000 m..