Shrubs, subshrubs or wiry perennial herbs, erect to prostrate, up to 1.5 m tall, the shrubs evergreen, glabrous, usually with dark glands; branching pseudo-dichotomous and/or lateral. Stems 2-4(6)-lined and ancipitous when young, sometimes becoming 2-lined or terete, eglandular or rarely black-dotted; cortex green or usually wine-red; bark smooth, red-brown to grey-brown. Leaves opposite, decussate, sessile or very shortly petiolate, free, in shrubs eventually deciduous at base; lamina entire, with venation pinnate, open or closed, the tertiary reticulation absent or rudimentary or rarely rather conspicuous; laminar glands pale, linear to punctiform, prominent; submarginal glands absent; intramarginal glands pale and/or dark, dense to rarely sparse; ventral glands absent. Inflorescence 1-flowered with branches pseudo-dichotomous or rarely up to 10-flowered with branches dichasial/monochasial or mixed, from up to 2 nodes, rarely with flowering branches from up to 10 lower nodes; bracts and bracteoles foliar, rarely somewhat reduced. Flowers stellate or rarely obconic (Sp. 4), homostylous. Sepals 5, free, persistent, erect to somewhat spreading in fruit, with margin entire or rarely black (Spp. 6(i) p.p., 7a) irregularly glandular-ciliate; laminar glands pale, linear to punctiform; submarginal glands absent; inframarginal glands or marginal glands pale and/or dark (black or rarely reddish) or absent. Petals 5, persistent, spreading after flowering, with apiculus subterminal or obsolete or absent; margin entire; marginal glands absent or few or rarely forming a row (Spp. 6(i) p.p., 7), black (sometimes prominent) or rarely pale; laminar glands linear to punctiform, pale and/or black. Stamen fascicles 3-5, obscure, or stamens not obviously in fascicles, persistent, with stamens 13-80; filaments basally united or apparently free; anthers yellow, gland amber or black; pollen type X. Ovary with 3-5(6) parietal (intrusive) to axile placentae, each ∞-ovulate; styles free, bases contiguous stigmas narrowly or scarcely capitate. Capsule 3-5(6)-valved, subconaceous to chartaceous, with valves longitudinally vittate, rarely also diagonally vittate (Sp. 6) or almost smooth (Sp. 7b) or thin-walled, bacciform and indehiscent (Sp. 10). Seeds cylindric, not or scarcely carinate; testa linear-reticulate to linear-foveolate or scalariform or scalariform-reticulate.
BASIC CHROMOSOME NUMBERS (X). 12, 9, 8; ploidy 2.
Wet to dry upland grassland, woodland clearings and disturbed ground; 1500-4300 m (New Guinea), c. 2800 m (Luzon), 1800-3997 m (Taiwan), 1800-3300 m (Java, Sumatra), 300-3600 m (Africa, Madagascar).
New Guinea (Papua/New Guinea and Irian Jaya), Philippines (northern Luzon), Taiwan, Indonesia (Sumatra, Java), 8(7) Flowers 12-30 mm in diam.; inflorescence branches (when present) Madagascar, Africa (Cape Province to Ethiopia, Sudan Republic, axillary; plant suberect to ascending 9 Zaire and Angola; also Cameroon and Fernando Poo).
12 species (+ 1 subspecies)
N.B. At a late stage in the work on Part 6, 1 realised that my original idea (Robson, 1973) that the relationships of two Taiwan species were with H. pulogense Merr. (from Luzon) was correct, and that they were not, as I had subsequently concluded (Robson, 1977a), related to a Japanese species of sect. 9. Hypericum, H. yezoense Maxim. Indeed, the shrublet or wiry herbaceous habit of these two species would be quite anomalous in sect. Hypericum. H. nagasawai Hayata and H. nokoense Ohwi have therefore had to be inserted in the numerical sequence of sect. Humifusoideum as Spp. 7 and 8 respectively.