Hypericum elodes (Nomenclature)
Perennial herb with herbaceous rootstock emitting erect (wholly submerged) to prostrate and rooting (terrestrial) stems up to 0.4(- 0.7) m, the terrestrial or shallow-water shoots bearing erect to ascending, terminal and axillary flowering shoots 0.05-0.2 m tall, the whole emergent plant up to sepals (dorsal) crisped-pubescent to tomentose or inflorescence puberulous, submerged parts shortly and finely villous to glabrous. Stems green to reddish, terete, 1 mm thick and threadlike (submerged) to 6 mm thick with swollen spongy internodes (shallow water or terrestrial); internodes up to 50(-80) mm long and 5 x as long as leaves (deep water) to shorter than leaves (terrestrial). Leaves sessile; lamina 5-30 x 2-22 mm, oblong-elliptic (deep water) to broadly elliptic or broadly ovate or orbicular, concolorous, not glaucous, plane, spreading; apex rounded, base cuneate (deep water) to cordate-amplexicaul; venation: 2-3 pairs of laterals curved-ascending from base or near base of midrib; tertiary reticulation dense, plane; laminar glands pale, dense, scattered, small; intramarginal glands pale, dense. Inflorescence 1-13-flowered from one node, terminal but usually apparently axillary when only one of uppermost pair of axillary shoots develops, laxly subcorymbiform to narrowly pyramidal, without lower flowering branches; pedicels 3-7 mm (-11 mm in fruit); bracts not auriculate; bracteoles triangular, obtuse, red-glandular-ciliate. Flowers 7-15 mm in diam., infundibular to subrotate, pseudo-tubular; buds cylindric to narrowly ovoid, subacute. Sepals 2.5-3.5 x 1-2 mm, subequal, c. 0.3-0.5 united, ovate or triangular-ovate to narrowly oblong, rounded, with margin glandular-ciliate; veins 3(5), branched or not; laminar glands pale, linear; marginal glands red, on short cilia. Petals lemon yellow, not tinged red, 8-10 x 2.7-3 mm, c. 3 x sepals, oblong-oblanceolate, subtruncate, without apiculus, in lower 0.25 with adnate ligulate appendage, apex free, trifid; laminar and marginal glands absent. Stamens 12-13, clearly 3-fascicled, with filaments c. 0.65 connate with line of hairs below free parts, longest c. 5-6.5 mm, c. 0.6 x petals; anther gland amber; lodicules 3, squamiform, 0.5 x 0.25 mm, elliptic, retuse. Ovary 1-locular, c. 2.5-2.7 x 1-1.5 mm, narrowly ovoid; styles 3, 2-2.5 mm, just shorter than ovary, narrowly outcurving. Capsule 4-5 x 2.5-3 mm, ovoid to cylindric, exceeding sepals. Seeds dark yellow-brown, 0.6-0.8 mm long; testa ribbed-scalariform (cf. Reynaud, 1985: 91, t. 2 ff. 3, 4).
2n = 16 (n = 8) (Al-Bermani et al., 1993), 20 (n = 10) (Delay, 1972), 32 (n = 16) (Robson, 1968); see sectional description.
In mesotrophic mires and pond or stream margins, usually in shallow water but sometimes in wet soil or deep water (to c. 50 cm); to 800 m in Spain and 770 m in the Azores, lowland elsewhere in Europe.
Portugal (W. & N.), Gibraltar, Spain (N. & central), Balearic Is. (extinct?), France (except SE), Belgium, Holland, England (except NE), Wales, Scotland (SW and western islands), Ireland (except centre); Azores. Unlocalised specimens in Herb. Schousboe are likely to come from Iberia rather than Morocco (Jahand. & Maire, Cat. Pls. Maroc 3:484 (1934)).
H. elodes is clearly derived from sect. Adenosepalum, its nearest relative being 13. H. coadunatum, from the Canary Islands. With regard to vegetative characters, H. elodes is more advanced than the H. caprifolium group (Spp. 13-15), and its occurrence in wet habitats is also a more extreme expression of a tendency shared with that group. The pseudo-tubular flower structure of H. elodes, however, is quite distinct, although Webb & Berthelot's figure of H. coadunatum suggests that the flower of that species may sometimes be basally contracted. The possession of a full-fledged syndrome of characters associated with specialised pollination, however, distinguishes H. elodes from all other species of Hypericum except those in the distantly related sect. 25. Adenotrias (Robson, 1972, 1981: 122) and justifies its position in an admittedly paraphyletic monotypic section. Two distinct basic chromosome numbers have been recorded for this species (n = 10, 8), see p. xxx.
The Greek ‘ελοδης has been transliterated by various authors as elodes or helodes, the Greek rough breathing (spiritus asper) sign ' thus being replaced by h, which it represents. Although this practice is to be recommended when coining new names based on Greek, an author's original spelling should be retained, and Linnaeus (following Clusius) used the form elodes. St-Lager (1880) and Mansfeld (1939) were therefore wrong to correct it to helodes.
The habitats of H. elodes are everywhere being increasingly threatened by drainage and water-extraction, and so its distributional area has been considerably reduced in the last century or so. The changes are most noticeable in the drier east (e.g. in Germany and north-east England), but they are occurring throughout the range of the species.
Glück (1911) described three forms of H. elodes that are related to the depth of water in which it is growing. The shallow-water form is finely pubescent with a long, creeping stem bearing ob- long-elliptic leaves and giving rise to emergent erect shoots. These bear broadly ovate, often cordate leaves and terminal (though often apparently axillary) inflorescences. Where the water has dried up or the vegetation is dense, the shallow-water form is replaced by the terrestrial form (later named H. helodes forma terrestre Glück), which is essentially similar but smaller and more reduced. In both these forms the creeping stems with 'primary' leaves can overwinter, producing aerial shoots the following summer. Where the water is deeper (up to c. 50 cm), a deep-water form occurs (Elodes palustris forma submersa Glück). In it the water shoots, which can exceed 40 cm in length, are paired, unbranched, filamentous, glabrous and sterile, with leaves narrowly to broadly elliptic. Proper leaves are mostly confined to the upper half of the shoot, those toward the base being small or even almost scale-like. If these shoots reach the surface of the water, they can immediately become aerial shoots. Hagemann (1983: 130) likewise demonstrated that the original shoots are plagiotropic, and that lateral shoots from them both (i) terminate in an inflorescence and (ii) produce axillary shoots that flower in the second year. The seeds of H, elodes are shed in August (in Germany), float for about three days, and then sink and overwinter in the mud at the bottom of the pond, etc. They germinate early the following year and are not inhibited by having dried out in the meantime.
It has no direct connection with Dillenius, but Dillenius studied the Buddle collection when working on the 3rd edition of Ray's Synopsis. The specimen is annotated with references to Ray's Historia plantarum (1686- 1688) and Petiver, Herb. Brit.: t. 60 f. 10 (1764).