Hypericum brachyphyllum (Nomenclature)
Shrub (0.3-)0.5-1(-1.5) m tall, usually 1-stemmed, erect, forming rounded bush, with branches erect Stems reddish to brownish, sometimes 4-lined when very young (especially just below node), very soon 2-lined and ancipitous, not becoming terete; cortex exfoliating in strips or plates; bark smooth, thin. Leaves sessile, 6-11(-12) x 0.5-0.7 mm, with those in axillary clusters usually half as long to as long, linear, plano-convex, glossy green above, with margin revolute but not concealing all surface beneath, the non-rib area almost smooth, chartaceous, deciduous at basal articulation (midrib base not prominent, cf. 9. H. tenuifolium), apex rounded-apiculate, base parallel; midrib unbranched; laminar glands few, dense, in 2 rows beneath. Inflorescence 3-c. 15-flowered, dichasial or occasionally mixed dichasial/pseudo-dichotomous, without accessory flowers, with 3-5-flowered dichasia or flowering branches from up to c. 10 nodes below, the whole narrowly cylindric; pedicel absent or up to c. 1 mm; bracts foliar. Flowers 10-13 mm in diam.; buds narrowly ovoid-conic. Sepals 5, 2.5-4.5 x 0.5-1 mm, unequal, linear, acute, 1 -veined. Petals 5, bright yellow, spreading, 5-8 x 2.5- 5 mm, obovate-spathulate, with apiculus lateral, acute. Stamens c. 40-45, longest 4-6 mm, c. 0.75-0.8 x petals. Ovary 3-merous, 2-2.5 x 0.5 mm, very narrowly cylindric, acute, placentation parietal; styles 3, 3 mm long, 1.2-1.5 x ovary, separating or deciduous in fruit. Capsule 3.5-5 x 1.5-2 mm, narrowly cylindric to narrowly ovoid-conic, exceeding sepals, thinly coriaceous. Seeds dull brown, 0.4-0.6 mm long, not carinate; testa finely reticulate (alveoli circular-hexagonal).
2n = 18 (n = 9) (Adams in Robson & Adams, 1968).
In moist habitats (pine flatwoods, pond margins, borrow pits, swamp woodland); lowland.
U.S.A. (Georgia and Florida to Louisiana).
H. brachyphyllum appears to be a derivative of 10c. H nitidum subsp. exile. It is very similar to the more reduced form of that subspecies in western Cuba, but less so to the larger (type) form in Cuba and north-western Florida. It can be distinguished from subsp. exile by the bushier habit, usually smaller leaves and smaller flowers, shorter styles and smaller capsule. It can, on the other hand, be confused superficially with 9. H. tenuifolium (a reduced 'form' of H. galioides, not of H. nitidum), but it has a bushy habit, 2-sided shoots, glossy leaves without prominent base or subapical hydathode, and finely reticulate seeds, and it grows in wet habitats.