Hypericum hypericoides (Nomenclature)
Shrub to wiry shrublet (0.05-)0.1-1 2(-l .5) m tall, erect or decumbent to prostrate, unbranched or with sparse lateral branches or branched from base and diffuse, sometimes mat-forming, lateral branches erect or spreading, sometimes also branched pseudo- dichotomously. Stems red-brown, 2-winged, the subsidiary lines only visible when very young; cortex exfoliating in thin strips or flakes; bark thin, reddish brown, not corky. Leaves sessile, spreading to rarely ascending, (5-)7-25(-34) x (1-)1.5-6(-8.5) mm, oblanceolate to narrowly oblong or linear, margin subrecurved, slightly paler beneath, not glaucous, subcoriaceous, eventually deciduous just above base, apex rounded to obtuse, base rounded or usually cuneate with paired basal glandiform auricles; venation: 1- 2 pairs of basal or near-basal veins sometimes visible, tertiary reticulation obscure or not visible; laminal glands dense. Inflorescence 1-3-flowered from 1-4 nodes, sometimes with flowering branches from up to 10 nodes below, the whole narrowly cylindric to narrowly pyramidal, or sometimes with a pair of inflorescences of the above type developing from one pseudo-dichotomous branching, or branching wholly pseudo-dichotomous; peduncle + pedicel 3-6 mm long, pedicel up to c. 1 mm (i.e. bracteoles touching or very near sepals); bracts foliar; bracteoles triangular-subulate. Flowers 10-15(-20) mm in diam.; buds compressed-globose to compressed-ellipsoid. Sepals 4, markedly unequal, enlarging somewhat in fruit; outer 5-12.5 x (2-)4-12(-13) mm, ovate-suborbicular to narrowly elliptic, obtuse or subapiculate to acute, margin plane, base shallowly cordate to broadly cuneate, basal veins 3, outer pair branched; inner minute or obsolete, up to c. 4 x 2 mm, lanceolate, acute, basal veins 3, outer pair branched. Petals 4, bright to pale yellow, (6-)8- 11 (- 12) x 2-4(-5) mm, 1(-1.5) x outer sepals, obovate to narrowly oblong-elliptic, apiculus subapical, obtuse (very short) or absent. Stamens c. 40-50, longest 3-5 mm long, c. 0.5 x petals. Ovary 2-merous, 3-4 x 0.8-1.5 mm, narrowly ovoid, acute, placentation parietal; styles 2, 0.5-1 mm long, becoming outcurved. Capsule 5-9 x 2-4 mm, narrowly compressed-ovoid to narrowly compressed-cylindric-ellipsoid, acute. Seeds purple-brown, 0.6-0.8 mm long, ecarinate; testa finely linear-reticulate to linear-foveolate.
2n = 18 (n = 9, Adams in Robson & Adams, 1968).
Dry open sandy habitats, especially pinewoods, roadsides and hill- sides, or moist shady woods and thickets, bogs and lake margins; lowland to 840 m (U.S.A., Arkansas), 1800 m (Guatemala), 1650 m (Jamaica) or 2900 m (Dominican Republic).
U.S.A. (south-east of line: eastern Texas, eastern Oklahoma to southern Missouri and eastward to New York (Long Island) and Massachusetts), eastern Mexico, Guatemala, Honduras Republic, Cuba, Hispaniola, Porto Rico, Jamaica, Bahamas, Bermuda. Introduced into the Azores.
H. hypericoides is clearly related to 25. H. crux-andreae but can be constantly distinguished by the 2-merous gynoecium, narrower leaves, smaller flowers and more richly branched stems. It is very variable in habit and in leaf and sepal shape and size. The form with erect stems unbranched at the base, narrowly oblong leaves and cylindric inflorescence (mainly in the S. Carolina/Georgia area) is morphologically nearest to H. crux-andreae. From this form, two lines of evolution have both resulted in plants with diffuse to prostrate stems, one in the northern range of the species in the U.S.A. (subsp. multicaule) and the other at high altitudes in the Dominican Republic (subsp. prostratum). The former has been treated as a species (H. stragulum Adams & Robson) and a variety (H. hypericoides var. multicaule (Michx. ex Willd.) Fosberg), but subspecies would seem to be the appropriate rank for this taxon.
Fawcett & Rendle (1926: 203) indicated the Ascyrum hypericoides L. type as Patrick Browne's specimen from Jamaica (LINN 944.2) named Hypericum angustifolium in Solander's hand with correction to Ascyrum, the correct specific epithet having been added by Sir J.E. Smith; and Adams (1957: 83) designated this specimen as a neotype, it having been added to the Linnaean herbarium only in 1758, after the publication of Species plantarum (1753). As I have explained, however (Robson, 1980), there is no need for the selection of a neotype, as Plumier's illustration is an appropriate lectotype.