Shrubs [trees] or vines. Stems ± erect; twigs multicellular stipitate-glandular-hairy and, sometimes, conspicuously strigose (hairs elongate, stiff, long-celled, eglandular), otherwise sparsely to densely unicellular-hairy. Leaves persistent or deciduous, alternate, sometimes pseudoverticillate [in whorls of 3]; blade ovate, elliptic, or slightly obovate, coriaceous, margins obscurely to clearly toothed or serrulate [entire], plane or revolute, surfaces multicellular, short-stalked stipitate-glandular-hairy (along with, in P. floribunda, stout, elongate hairs associated with marginal teeth, and unicellular-hairy on midvein adaxially); venation brochidodromous to reticulodromous (veins of varied thickness and conspicuousness). Inflorescences axillary or terminal panicles or racemes, 15-35-flowered, (borne the year preceding flowering). Pedicels: bracteoles 2, proximal or distal. Flowers: sepals 5, slightly connate, ovate [oblong-lanceolate]; petals 5, connate for nearly their entire lengths, white, corolla urceolate to cylindric-urceolate, lobes short; stamens 10, included; filaments straight or geniculate, glabrous or hairy, with 2 stout, minutely papillose spurs at anther-filament junction; anthers without awns, dehiscent by elliptic pores; pistil 5-carpellate; ovary 5-locular; stigma capitate. Fruits capsular, subglobose or globose to ovoid, (with unthickened sutures), dry. Seeds 40-100, ellipsoidal to obovoid, ± rectangular or angular-ovoid, or narrowly conic, flattened or not, (sometimes slightly winged); testa cells elongate or isodiametric. x = 12.
Fls 5-merous, cal persistent, campanulate, the sep leathery, valvate at base; cor ovoid, much-constricted above, 5-saccate at base alternately with the sep, sharply 5- angled in bud; stamens included, much shorter than the cor; filaments flat, sometimes geniculate, glabrous; anthers oblong, opening by 2 terminal pores, bearing 2 short, outwardly deflexed spurs; ovary 5-lobed; style columnar; stigma truncate; capsule globose, not retuse, not thickened at the sutures; seeds few in each locule, narrowly oblong, finely cellular-reticulate; shrubs with alternate, evergreen lvs and white fls in terminal panicles. 10, N. Amer., e. Asia.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.