Hypericum nagasawai (Nomenclature)
Perennial herb or deciduous shrublet, 0.05-0.35 m tall, suberect to ascending from creeping branching rooting base, with stems solitary or caespitose, unbranched or branched above, wiry. Stems 2(4)- lined, eglandular; internodes c. 5-15 mm, shorter than leaves. Leaves sessile or subsessile; lamina (3-)8-25 x 3-12 mm, ovate or oblong to elliptic or oblanceolate or linear, glaucous or sometimes minutely papillose beneath, chartaceous to subcoriaceous; apex acute to rounded, margin entire, recurved, base cuneate to angustate; venation: 3-4 pairs of main laterals from lower third of midrib, sometimes forming marked submarginal vein, tertiary venation lax or obscure; laminar glands pale, somewhat elongate to punctiform, rather sparse, prominent above; intramarginal glands black, dense or irregular. Inflorescence 1-11-flowered from 1-2 nodes, sometimes with flowering branches from 1-2 nodes below, the whole subcorymbiform; pedicels 4-8 mm; bracts and bracteoles 2- 6 mm long, lanceolate to linear, entire. Flowers 15-30 mm in diam., stellate; buds ovoid to ellipsoid, obtuse. Sepals 5, equal, 3-7.5 x 0.8-2.5 mm, in bud and fruit, ovate-lanceolate to narrowly oblong, obtuse to acute, entire or rarely with 1-2 glandular cilia; veins 5, outwardly branched; laminar glands pale or rarely black, striiform to punctiform or rarely linear; marginal glands black and sometimes pale, regular or irregular, immersed or rarely on cilia, or absent. Petals 5, bright yellow, not tinged red in bud, 8-17 x 4-7 mm, 2-2.5 x sepals, obovate or oblong-obovate to oblanceolate, usually entire, laminar glands pale and rarely black, linear to punctiform, or rarely absent, marginal glands black, sessile or occasionally on cilia, distal and few or subapical and solitary. Stamens 40-80, not or obscurely fascicled, longest 4.5-8 mm, 0.5-0.8 x petals; anther gland black. Ovary 3-locular, 2-2.5 x 1-1.5 mm, narrowly ovoid to ellipsoid- ovoid; styles 3, 3.5-7 mm, 1.3-3 x ovary, spreading from near base; stigmas narrowly or scarcely capitate. Capsule (5-)6-7 x 3.5-5 mm, c. 1.5 x sepals, narrowly to broadly ovoid; valves narrowly longitudinally vittate. Seeds dark brown, c. 1 mm long, not or scarcely carinate, apiculate; testa finely scalariform-reticulate to linear-foveolate.
2n = 36 (n = 18, Hsu, 1968).
Stony or rocky slopes, roadsides and open areas of conifer forests and subalpine woodland; 2300-3997 m.
Taiwan (central mountains).
H. nagasawai is quite closely related to H. pulogense, differing from it inter alia by the more slender habit, the frequently narrower leaves and the black glands on the anthers and elsewhere. The variation from the mainly northern broad-leaved form with sepals and styles about 1.3 times as long as the ovary (H. nagasawai s.s.) to the southern narrow-leaved form with acute sepals and styles 2 or more times as long as the ovary (H. randaiense) appears to be continuous; and indeed the trends in leaf form, sepal shape and style length are only partially correlated. It is not possible, therefore, to recognise H. randaiense as a distinct species. Similarly, plants described as H. suzukianum and H. hayatae, respectively, are more extreme forms of trends within H. nagasawai; and the occasional forms with black-glandular-ciliate sepal margins (H. taiwanianum) are linked to the more typical forms by specimens with one or two glandular cilia on each sepal margin.