Pieris

Illustrator: Yevonn Wilson-Ramsey

Copyright: Flora of North America Association

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.

Distribution

se United States, West Indies (Cuba), e Asia.

Discussion

Ampelothamnus Small; Arcterica Coville; Portuna Nuttall

Species 7 (2 in the flora).

Selected References

Judd, W. S. 1982. A taxonomic revision of Pieris (Ericaceae). J. Arnold Arbor. 63: 103–144.

Setoguchi, H., W. Watanabe, Y. Maeda, and C. I. Peng. 2008. Molecular phylogeny of the genus Pieris (Ericaceae) with special reference to phylogenetic relationships of insular plants on the Ryukyu Islands. Pl. Syst. Evol. 270: 217–230.

Lower Taxa

Pieris floribunda, Pieris phillyreifolia

Key

1	Inflorescences axillary racemes; capsules with placentae central to nearly basal; styles strongly sunken into ovary apex; seeds with isodiametric testa cells; filaments geniculate, glabrous; twigs multicellular stipitate-glandular-hairy.	Pieris phillyreifolia
1	Inflorescences terminal panicles; capsules with placentae subapical; styles slightly sunken into ovary apex; seeds with elongated testa cells; filaments straight, hairy; twigs multicellular stipitate-glandular-hairy and conspicuously strigose (hairs stout, elongate).	Pieris floribunda