Hypericum tortuosum (Nomenclature)
Shrub or shrublet to c. 0.5 m tall, much branched, round-topped or trailing, with branches divergent-ascending, flexuous; wholly glabrous or with young stems and leaves beneath densely and minutely papillose; dark glands absent. Stems persistently 4-lined; cortex reddish; bark finely longitudinally ribbed. Leaves opposite, free, all sessile or lower petiolate, with petiole up to 4 mm long; lamina 8-17(-23) x 4-11 (-15) mm, obovate or oblanceolate to elliptic-oblong or suborbicular, paler beneath, glaucous on both sides (densely so beneath), coriaceous; apex obtuse (or subacute?) to rounded, margin revolute, base cuneate; venation: 4-5(-8) pairs of laterals, closed, without cross-veins but sometimes with rather obscure tertiary reticulation; laminar glands dense, obscure, not prominent or slightly so beneath or on both sides; intramarginal glands rather dense, obscure. Inflorescence 1-c. 35-flowered, terminal, subumbellate, occasionally with single axillary flower from lower node; uppermost leaf pair modified as bracts, oblong, amplexicaul; bracteoles minute, basal; pedicels 4-8 mm long, slender. Flowers c. 10 mm in diam.; buds ellipsoid, obtuse. Sepals 4-6 x (1-)1.5-2.5 mm, free, imbricate, unequal, elliptic to oblong-oblanceolate or oblong, acute to rounded, thinly chartaceous, margin entire; veins 7(-l1), prominent, pinnately branched; laminar glands absent. Petals bright yellow, not tinged red, 6-7 x 2-3 mm, 1.5-2 x sepals, elliptic to oblanceolate, rounded. Stamens c. 25, longest 4-7(-7) mm, c. 0.7 x petals. Ovary 1.5-2 x 1-1.7 mm, ovoid-ellipsoid, acute; styles 3-5 mm long, 2-2.5 x ovary, curved-ascending. Capsule c. 5 x 2.5 mm, ellipsoid, acute, subcoriaceous, with valves glandular-verrucose (vesiculate), about equalling sepals. Seeds dark brown, c. 1.2 mm long; testa rugulose.
Among rocks and crags (sometimes limestone) on hillsides; (33-) 200- 1200m.
Socotra (Hagghiher Mts, Reighid, extreme west).
H. tortuosum is apomorphic relative to the other two Socotran species of sect. Triadenioides in its less woody, spreading to pendulous habit, smaller size, larger sepals and verrucose capsules; and its subumbellate inflorescence and usually petiolate leaves are also specialised relative to H. scopulorum. The population originally described (from the central mountains) has leaves (except the bracts) all, or at least the lower, petiolate with 4-5 lateral veins and no visible tertiary reticulate venation, and the young stems and lower leaf surface are smooth to undulate; whereas the western lowland population has wholly sessile, larger leaves and sometimes larger flowers, the leaves may have up to 8 pairs of lateral veins and obscurely visible tertiary reticulate venation, and the young stem and the leaves beneath are sometimes minutely papillose. The western population therefore approaches H. scopulorum in several characters; but in others (e.g. the prostrate habit) it is typical of H. tortuosum. It would seem, then, to be the remains of the stock from which the above two species diverged, an interpretation that is supported by the presence in some leaves of more numerous lateral veins than is usual in either species, thus showing a tendency towards H. socotranum (sect. 1. Campylosporus). These characters of the western population do not, however, provide a clear-cut separation of the two populations, e.g. the lower leaves of the central mountain population may be shortly petiolate (Miller et al. M.8680), or leaves at several upper nodes may be wholly sessile (Balfour, 1888: t. 4B). I therefore hesitate to treat these populations as separate taxa, preferring to regard them as geographically distinct, respectively plesiomorphic and apomorphic parts of an almost continuous morphocline.