Hypericum ascyron (Nomenclature)
Perennial herb 0.5-1.3(-2) mm tall, erect or sometimes ascending from shortly creeping woody base, with stems single or few, caespitose, unbranched or branched above or almost throughout. Stems 4-angled when young, becoming 4-lined or occasionally internodes 2-lined below; internodes 2-12 mm, exceeding leaves or shorter than them. Leaves sessile; lamina (30-)40-97(-120) ´ (4-)7-35(-40) mm ovate-lanceolate or ± narrowly lanceolate or narrowly oblong or narrowly elliptic to oblong-linear or oblanceolate, rather paler beneath, not glaucous, plane, chartaceous; apex acute to subapiculate or obtuse (or lowermost rarely rounded), margin entire, base cuneate to cordate-amplexicaul; venation: 4-7 pairs of main laterals from lower half of midrib, with subsidiary midrib branches and dense tertiary reticulation not prominent, often obscure; laminar glands pale, dense, unequal dots or short streaks; intramarginal glands pale, small, dense. Inflorescence 1-c. 35-flowered from 1-5 nodes, the whole subcorymbiform to narrowly pyramidal, sometimes with flowering branches from up to 4 nodes below; pedicels 5-30 mm in fruit; bracts and bracteoles foliar but smaller and often broader, more rarely linear-lanceolate and deciduous. Flowers 30-70(-80) mm in diam., stellate with petals spreading to reflexed; buds broadly to narrowly ovoid, rounded to subacute. Sepals (3-)5-15 ´ (1.5-)2-7(-10) mm, free, imbricate, subequal to unequal, the outer ones sometimes foliaceous, erect in bud and fruit, oblong to elliptic or ovate to ovate-lanceolate or obovate, rounded to obtuse or more rarely subacuminate to acute, entire; veins c. 11-17, branching and uniting distally, midrib scarcely differentiated; laminar glands linear, distally interrupted to striiform; marginal glands spaced, small. Petals bright (to golden?) yellow, sometimes tinged red in bud, 14-41 ´ 5-20 mm, 2-3 ´ sepals or relatively shorter when sepals foliaceous, obovate or oblong-obovate to oblanceolate, often somewhat spathulate to subunguiculate, strongly curved to almost straight, rounded or obtuse to rarely acute or acuminate, with apiculus short and rounded or absent, margin entire; laminar glands pale, linear to distally striiform, or absent; marginal glands absent. Stamen fascicles 5(4?), distally red, each with c. 30 stamens, longest 9-25 mm, c. 0.4-0.67 ´ petals; anther reddish, gland amber. Ovary 5(4)-locular, 4-7(-9) ´ 3-5 mm, broadly ovoid to narrowly ovoid-pyramidal or ellipsoid; styles 5(4), 2.5-15 mm, c. 0.5-2 ´ ovary, free or up to 0.8 coherent or connate; stigmas broadly capitate to infundibuliform. Capsule 9-22(-30) ´ 5-13 mm, broadly to narrowly ovoid or ovoid-pyramidal or rarely narrowly cylindric, 2-3 ´ sepals, obtuse to rounded, with numerous narrow longitudinal vittae. Seeds dark red-brown, 1-1.5 mm, cylindric, not or slightly curved, deeply carinate or narrowly winged, sometimes with slight terminal expansion; testa densely shallowly linear-reticulate.
2n = c. 22-20 (Krasnoborov et al., 1980), 18 (Kogi, 1984; Probatova & Sokolovskaya, 1984; Malakhova, 1990; Nishikawa, 1990; Malakhova & Markova, 1994; Stepanov, 1994, "H. gebleri"; Probatova, Shatokhina & Rudyka, 2005, “H. gebleri”), n = 9, (Nielsen, 1924); 16 (Krogulevich, 1978).
Moist to dry meadows or grassy or rocky slopes, sometimes in forest or amongst scrub, streamsides and river banks; 0-2800(-3600) m.
Russia (Altai to Kamchatka and Kurile Is., Sakhalin), Mongolia, Korea, Japan, Taiwan, China (all provinces except Xizang and Qinghai), Vietnam (north); Canada (Quebec, Ontario, Manitoba ?), U.S.A. (Minnesota to Vermont and S. to Missouri, Illinois and Maryland).
H. ascyron is a very variable species or species complex with a very wide distribution. Although several variants have been recognised as varieties or even species, the variation appears to be almost continuous. Seven characters or character groups appear to vary independently or with insufficient correlation or disjunction to be useful for specific delimitation:-
(1) Habit / inflorescence: from simple, unbranched, 3-flowered to a) pyramidally branched with flowers on each branch or b) pyramidally branched with flowers on each branch or (c) widely corymbiform ('var.' umbellatum).
(2) Leaves: from large, triangular-lanceolate, acute to a) small, narrowly oblong to linear, acute or b) oblong, obtuse to (upper) very rarely almost rounded or c) rather broadly elliptic and subacute ('H. hemsleyanum') to almost rounded.
(3) Flowers: from large to small, varying approximately with (1) and (2) except for a) an extra-large-flowered form with long, mostly united styles ('var. longistylum' in part) and b) Manchurian plants with large flowers and small leaves.
(4) Sepals: from oblong or oblong-elliptic, rounded to a) narrowly oblong, rounded (subsp. gebleri), b) ovate, acute (subsp. pyramidatum), c) obovate to foliaceous, rounded (var. macrosepalum) or ovate-lanceolate.
(5) Styles: from medium long and up to 0.75 united to a) long, c. 0.8 connate (see (3) above) or b) shorter than ovary and free (mostly subsp. gebleri). (5) varies with (4) in general but not completely. Some small-flowered, small-leaved plants from south China and Japan ('forma angustifolium') have styles about half connate, while some large-flowered plants with broad sepals have short free styles (Nei Mongol).
(6) Capsules: from large ovoid-pyramidal to a) small ovoid-cylindric (subsp. gebleri) or b) narrowly cylindric ('var. giraldii').
(7) In addition, the pedicels vary in length from c. 10 mm to a) 30 mm or b) c. 5 mm ('var. umbellatum').
The most frequently distinguished taxon has been H. gebleri Ledeb., which most Russian authors have recognised, as it occurs through southern Siberia from Altai to the Korean border along with distinct larger-flowered less-branched forms and is present alone in Kamchatka, the Kuriles and Sakhalin. On the other hand, Chinese authors have tended to include it in H. ascyron, because it apparently occurs only in the extreme north of that country and may include intermediate forms there.
The North American population was early recognised at species level (H. pyramidatum, H. macrocarpum, etc.), and Kimura (1951) maintained it as var. americanum partly on the basis of its rather acute sepals. Already in 1859, however, Maximowicz had expressed the opinion that it could not be distinguished from the Asian plants by this or any of the other differentiating characters that had been proposed; and I can confirm that two of Kimura's other characters - leaf shape and styles shortly connate - do not help to define a discrete taxon. The American plants, however, all have short styles and most have acutish sepals, a combination that does not occur elsewhere in the species. Kimura's other varieties were based mainly on these style length and union criteria:- var. longistylum with styles up to 15 mm, 2/3 to 3/4 united, var. ascyron with styles up to 7 mm, 1/3 to 2/3 united (both with styles equal to or longer than the ovary); and var. brevistylum with styles shorter than the ovary and free.
In these circumstances it seems best to distinguish the northern Asian H. gebleri and the North American H. pyramidatum as subspecies (although further investigation may show that the intermediate forms in the former are too numerous to maintain it even at this rank). It seems impossible to recognise the long-styled (mainly large-flowered and northern) plants and the narrow-fruited central Chinese ones (respectively vars longistylum and giraldii [» var. hupehensis]) as distinct taxa, as both represent extremes of continuous variation (see Introduction, p. ). Likewise, the narrow-leaved small-flowered form from south China (wrongly identified by me and others as var. angustifolium Y. Kimura) merges with more typical forms.
Apart from having only 4 styles, H. kelleri H. Léveillé (as described) would appear to be typical H. ascyron.
H. ascyron var. hupehensis Pamp. is very like var. giraldii, but differs in that the leaves are not or scarcely cordate, the flowers are larger (40-50 mm in diam.) and the capsule is shorter (8-10 mm wide).
H. ascyron var. vilmorinii Rehder (Type: cf. Sprague in Curtis' Bot. Mag.: t. 8557 (1914) as H. ascyron) appears to be a re-naming of H. ascyron var. macropetalum (1904).
"H. ascyron f. longistylum Maxim." is also cited in the publication of H. sagittifolium Koidz.