Tripentas (Nomenclature)
Perennial herb with stems up to 0.4 m or longer, with simple hairs, with dark (reddish) glands on sepals only; branching below inflorescence lateral. Stems terete, eglandular; cortex not exfoliating; bark absent. Leaves opposite, decussate, sessile, free, persistent; lamina entire, with venation subpalmate to palmate, closed except for lowermost veins, with tertiary venation densely reticulate; laminar glands punctiform; marginal gland dots dense; ventral glands absent. Inflorescence 1-13-flowered, with branching dichasial (first node) then monochasial, from one node, without lower flowering branches; bracts and bracteoles reduced, transitional in form to sepals. Flowers pseudo-tubular, homostylous. Sepals 5, c. 0.3-0.5 united, persistent, erect in flower and fruit, with margin glandular-ciliate; veins 3(5); laminar glands pale, linear; marginal glands reddish, flat-topped. Petals 5, persistent and twisting together round developing capsule, without apiculus; marginal and laminar glands absent. Stamen fascicles 5, united 2+2+1 (i.e. '3'), persistent, totalling 12-13 stamens; filaments 0.6-0.7 united; anthers yellow, gland amber; pollen type IX; lodicules 3, scale-like, alternating with stamen fascicles. Ovary with 3 parietal placentae, each ∞-ovulate; styles 3, free, with bases discrete; stigmas narrowly capitate. Capsule 3-valved, chartaceous, with valves narrowly longitudinally vittate. Seeds narrowly cylindric to ellipsoid-cylindric, not carinate, without apical expansion; testa ribbed-scalariform.
BASIC CHROMOSOME NUMBERS (x). 10 and/or 8; ploidy 2 and possibly 4. My count (n = 16; Robson, 1968), for which the slide preparation used has deteriorated and cannot now be checked, and that of Al-Bermani et al. (1993) - 2n = 16, i.e. n = 8, fit better with the morphology of H. elodes, which is specialised in relation to H. coadunatum (n = 9) in all respects except for the free leaf pairs. On the other hand, Delay's count (n = 10; Delay, 1972) is supported by a photograph and would imply that H. elodes is sister species to the whole H. caprifolium group (Spp. 13-15; n = 9-8). Only further counts will reveal which is correct.
Wet soil, mesotrophic mires, along streams and in ponds on acid soil, sometimes in deeper water; sea level to c. 700 m (Spain, Azores).
British Isles; continental Europe from France, Spain and Portugal eastward to NW Germany (and scattered localities further east), Austria ? and NW Italy; Azores. One species.
In Part 1 (Robson, 1977: 336), I excluded ‘Hypericum 9. Lin. Sp. 784’ from Adanson’s protologue of Elodes, following Spach (1836) and Reichenbach (1841), a procedure that enabled me to choose Spach’s Elodes palustris as the lectotype of the genus and thus of the section. According to the Vienna Code (McNeill et al., 2006), I was in error. Art. 10.3 cites Elodes Adans. as having three elements in the protologue, only one of which (my excluded reference) refers to a validly published name of a species, H. aegypticum L., which belongs to Sect. 25. Adenotrias. The genus Elodes Adans. must therefore be typified by that species.