Shrub 0.05-0.45 m tall, decumbent, spreading, with branches erect to ascending from decumbent rooting base, forming low compact mats. Stems reddish, 4-lined and ancipitous; cortex exfoliating in strips; bark reddish brown, smooth, thin. Leaves sessile or with pseudopetiole to 1 mm long; lamina 4-25 x 2-12 mm, oblong or elliptic to oblanceolate or obovate, plane, paler beneath, chartaceous, persistent or breaking off at top of pseudopetiole, apex rounded, base cuneate; venation obscure: (2)3(4) pairs of main laterals with- out visible subsidiaries or tertiaries, only midrib prominent; laminar glands dense. Inflorescence l(3-5)-flowered, terminal; pedicels 1.5-3 mm long; bracts foliar. Flowers 20-25 mm in diam.; buds broadly ovoid. Sepals 5, 4-5 x 2.5-3 mm (to 6 x 3.5 mm in fruit), not imbricate, subequal, persistent, broadly elliptic to elliptic-spathulate or obovate, obtuse, plane, basal veins 3, not or obscurely branched. Petals 5, golden yellow, becoming reflexed, 6-10.5 x 3-5 mm, 1.5- 2 x sepals, oblanceolate, with apiculus lateral, obtuse. Stamens c. 100, longest 6-9 mm, c. 0.8 x petals. Ovary 3-merous, 3-4 x 2-3 mm, narrowly ovoid, acute, placentation incompletely axile; styles 3, 2.5-4 mm long, 0.85-1 x ovary, separating in fruit. Capsule 8-12 x c. 5 mm, narrowly ovoid to ovoid-cylindric, acute, rounded-trigonous, exceeding sepals, thinly coriaceous. Seeds 1.5-2 mm long, dark brown, narrowly to broadly carinate; testa finely scalariform.
Seepage areas, moist crevices and sometimes ditches and road embankments; 900-1560 m.
Eastern U.S.A. (southern Appalachian Mts - N. Carolina and Georgia - and in adjacent S. Carolina).
Although H. buckleyi differs markedly in habit and leaf-shape from all other 5-petalled species in sect. Myriandra, the large ovoid capsules and relatively broad leaves indicate that its nearest relative is H. prolificum, of which some montane specimens from N. Carolina (e.g. Leonard, Radford & Moore 1805 (BM)) resemble it most closely. The original spelling, buckleii, was correct until recently according to the International Code of Botanical Nomenclature (Art. 73.1), as Curtis's latinisation of Buckley was clearly intentional. There was therefore no alternative to rejecting the usual spelling, buckleyi, pace Adams (1962: 37); and I adopted the form buckleii in The New Royal Horticultural Society Dictionary of Gardening (Robson, 1992), European Garden Flora (Robson, 1995) and various herbarium labels; and Wilbur (1995) also pointed out this necessary change. In the Tokyo edition of the I.C.B.N. (1994), however, spellings of epithets based on latinisations of modern names have been prohibited retrospectively (Art. 60.11), so the form buckleyi is now the obligate one. Barker & Cheek (1994) reached the same conclusion; but their statement that the leaves of H. buckleyi have black glandular dots is erroneous.