Hypericum harperi
Perennial herb 0.3-1 m tall, erect, branched from the base and usually with flowering branches from median and upper stem nodes. Stems green, 4-lined, densely gland-dotted, aerenchymatous at the base; internodes 8-20 mm long, about equalling leaves. Leaves sessile, ascending, deflexed when fading, lamina 10-30 x 3-5(-8) mm, narrowly oblong-elliptic (lower) or lanceolate to linear-lanceolate, margin plane, concolorous, not glaucous, subcoriaceous?; apex acute, base cuneate to rounded-subamplexicaul, sometimes subdecurrent; basal or near-basal veins l-3(-5), midrib unbranched or with 1(2) pairs of branches, tertiary reticulation not visible; laminar glands dense, not prominent. Inflorescence up to c. 30-flowered, monochasial after c. 4th grade, with branches from up to 16 lower nodes, the whole broadly pyramidal to subcorymbiform; pedicels 1.5-2 mm long; bracts 2-6 mm long, lanceolate to subulate. Flowers c. 4-10 mm in diam., stellate. Sepals 3-5 x 0.8-1 mm, often unequal, lanceolate, acute to acuminate; veins 3-5, unbranched, all or only midrib prominent; glands linear, distally punctiform. Petals orange-yellow, 6-10 x 5-7 mm, c. 2 x sepals, obovate; apiculus obtuse; glands linear, interrupted distally. Stamens 50-80, irregularly (?) grouped, longest 3-6 mm long, c. 0.5 x petals. Ovary c. 1-1.5 x 0.7-1 mm, ovoid; styles 3, 2-4 mm long, 2-3 x ovary, divergent-incurved; stigmas capitate. Capsule 3-4.5 x 2-2.5(-3 ?) mm, ellipsoid to rostrate-subglobose, shorter than or equalling sepals. Seeds 0.5-0.6(0.65) mm long, testa obscurely linear-reticulate to irregularly reticulate.
2n = 24 (n = 12 -Webb, 1980).
Open Taxodium swamps and wet pine barrens; lowland.
South-eastern U.S.A. (coastal plain of South Carolina, Georgia, and northern Florida).
Despite the rather scathing comments by Fernald & Schubert (1948: 207) about Keller's habitual assumption that there were eastern North American species awaiting recognition, I agree with Webb (1980) that H. harperi is a good candidate for such recognition. Although clearly closely related to H. denticulatum subsp. acutifolium, it differs from the latter in its aquatic habitat and correlated spongy, aerenchymatous stem base, as well as in having rather smaller flowers and more stem branches. The Floridan collections of H. [denticulatum subsp. acutifolium] H.erythraeae are intermediate in the last two characters, though apparently not in habitat. In addition, Webb (1980) has shown that H. harperi contains C-glycosyl flavones, whereas H. denticulatum does not. In addition to these ecological, morphological, and chemical differences, H. harperi remains distinct in localities where it grows alongside H. denticulatum, presumably because populations of the latter taxon are mostly tetraploid (2n = 48) and would therefore form triploid hybrids with H. harperi.
The selection of Harper 1006 as lectotype of Hypericum harperi R. Keller by Rodriguez Jimenez (1973) is therefore unacceptable, being later; and the Berlin specimen, being the only one seen by Keller, must be the lectotype, not the BM one as designated by Webb.