Hypericum monogynum (Nomenclature)
Shrub 0-5-1-3 m tall, bushy or usually with branches lax, spreading. Stems red, 2(4)-lined and ancipitous when young, soon terete; internodes 10-50 mm long, shorter than leaves; bark orange-brown. Leaves sessile or with petiole up to 1-5 mm long; lamina 20-112 x 10-41 mm, oblanceolate or elliptic to oblong or more rarely lanceolate to ovate-triangular or ovate, acute to rounded, often minutely apiculate, margin plane, base cuneate to rounded or in upper ones sometimes truncate to cordate, paler beneath, not glaucous, chartaceous; venation: 4-6 pairs main laterals, branched, not always distinct from the midrib branches, with tertiary reticulum dense, conspicuous; laminar glands very small, punctiform; ventral glands absent. Inflorescence l-15(-30)-flowered, from apical node, loosely subcorymbiform, some- times also from uppermost 1-3 nodes, rarely with 1-2 pairs of subsidiary branches; pedicels 8-28(50) mm long bracts small, linear-lanceolate, caducous. Flowers 30-65 mm in diam., stellate; buds ovoid, subacute to obtuse. Sepals 4.5-13 x 1.5-6 mm, imbricate, equal or unequal, ± spreading in bud and fruit, broadly or narrowly elliptic or oblong to lanceolate or oblanceolate, acute to rounded, margin entire; midrib distinct, other veins not prominent; laminar glands ± numerous, basally linear to striiform, punctiform towards apex. Petals golden yellow to lemon-yellow, not tinged red, spreading, 20-34 x 12-20 mm, 2.5-4.5 x sepals, triangular-obovate, with apiculus lateral, acute to rounded or obsolete; margin entire, eglandular. Stamen fascicles each with 25-35 stamens, longest 18-32 mm long, almost equalling petals; anthers yellow to pale orange. Ovary 2.5-5 x 2-5-3 mm, ovoid or ovoid-conic to subglobose; styles 12-20 mm, long, c. 3-5-5 x ovary, united almost to the apices then outcurved or very rarely free up to halfway; stigmas small. Capsule 6-10 x 4-7 mm, broadly ovoid or rarely ovoid-conic to subglobose. Seeds dark reddish- brown, c. 2 mm, long, cylindric, narrowly carinate, shallowly linear-reticulate to linear-foveolate.
2n = 42.
Cliffs, glens, gorges, limestone hills, roadsides, in dry localities; 0-1500 m.
SE. China (Shaanxi, Sichuan, Guizhou, Guangxi, Hubei, Jiangxi, Guangdong, Fujian, Zhejiang, Anhui, Jiangsu, Shandong; also recorded from Henan and Hunan). Probably introduced in the eastern lowlands. Native or possibly naturalised in Taiwan.
H. monogynum is a very variable species in which the main clinal variation has been complicated by another set of variations in part of the range of the species.
(i) The form with elliptic to oblanceolate, acute, cuneate-based leaves, a very lax inflorescence and narrowly elliptic, acute sepals (Kuntze's subsp. salicifolium) is nearest to H. gaitii of India. It is a native of upland regions of central China (Shaanxi, Sichuan, western Hubei), whence it has apparently spread (at least partly by introduction) into the coastal lowlands from Fujian north to Shandong. From these lowland regions it was introduced into Japan at an early date and brought to Europe from there by Oldham in 1861. It is now cultivated widely in Europe, N. America and other temperate regions, where it is more or less hardy.
(ii) In eastern Hubei and Jiangxi, form (i) is gradually replaced by one with shorter, oblong leaves, obtuse to rounded at the apex and rounded at the base, a less lax inflorescence and narrowly oblong, obtuse sepals (Kuntze's subsp. obtusifolium), which attains its extreme form in coastal Guangdong. From this area it was introduced into England by Sir George Staunton and David Nelson, who accompanied Lord Macartney on his famous mission to China in 1793. It was grown in the Earl of Northumberland's garden at Stanwick and subsequently at Chelsea Physic Garden by Philip Miller, whose illustration is the type of both H. monogynum and H. chinense L. This lowland form was introduced to India (Calcutta Botanic Garden) and is now widely cultivated in the warmer regions of the world. According to Miller, it can survive outside in a very warm situation in England.
The form native or naturalised in Taiwan (Kuntze's subsp. latifolium) is somewhat intermediate between forms (i) and (ii) but has solitary flowers.
(iii) Throughout the range of form (i) there are plants with a similar lax inflorescence but with broader leaves and sepals (the latter sometimes being foliaceous). The leaves may vary from broadly elliptic, acute and cuneate at the base (e.g. Fang 12366 from Chengdu, Sichuan) to broadly oblong, rounded and cordate at the base (e.g. Wilson 1094 from Changyang, western Hubei). Plants of the latter extreme form were wrongly identified by Sargent (Pl. Wilsonianae) as H. prattii (q.v.). Specimens of this form have also been seen from Guizhou and Shandong, perhaps introduced.
(iv) In an extreme form of (iii), occurring in Sichuan, the leaves are short, elliptic to ovate or triangular-ovate, obtuse to rounded at the apex, broadly cuneate to rounded at the base (e.g. Xiong & Li 91225 and 91554 (SZ), both from Nanchuan Xian). The sepals, however, are long and narrow, as in H. cohaerens.
Although these forms differ widely in their extreme manifestations, and indeed appear to be related to different species and even sections (Robson 1985: Fig 4), it does not seem possible to recognise them taxonomically owing to complete morphological and geographical intergradation. Typical examples of the forms may be identified by the following key:
1. Leaves narrowly elliptic to oblanceolate, apex acute to subacute, base cuneate; inflorescence usually lax ('salicifolium') ... Form (i)
Leaves broadly elliptic to oblong or ovate (or, if oblanceolate, then apex obtuse to rounded), apex obtuse to rounded or rarely acute, base cuneate to sub-rounded; inflorescence usually ± dense or flowers solitary ... 2
2. Leaves narrowly oblong to lanceolate, apex obtuse to rounded, base rounded or rarely cuneate ('obtusifolium')...Form (ii)
Leaves broadly oblong or broadly elliptic to ovate (or if lanceolate, then acute), apex acute to rounded, base rounded to cordate...3
3. Leaves broadly oblong to broadly elliptic or lanceolate; sepals broadly elliptic to broadly oblong or foliaceous, apex obtuse to rounded ('latisepalum') ... Form (iii)
Leaves broadly elliptic-oblong to triangular-ovate or ovate; sepals narrowly elliptic, apex acute ('ovatum') ... Form (iv)