in A. von Humboldt et al., Nov. Gen. Sp. 3(fol.): 215.
plate 257. 1819, name conserved ,.
Subshrubs or shrubs. Stems erect; twigs glabrous or hairy, sometimes glandular. Leaves deciduous (G. brachycera persistent); blade obovate or ovate to oblong or oblanceolate, membranous or coriaceous, margins entire or crenate (sometimes serrulate) [glandular-crenate], plane or revolute, glabrous or hairy; venation reticulodromous. Inflorescences axillary or terminal racemes, 2–8-flowered, sometimes flowers solitary. Flowers: sepals (4–) 5, sometimes vestigial, connate basally, deltate (straight or inflexed in fruit); petals 4–5, connate for nearly their entire lengths, greenish white or white to pink or orange to red, corolla urceolate, campanulate, or campanulate-conic, lobes much shorter than tube; stamens 10, included, (slightly shorter than corolla); filaments straight, flattened, glabrous or pilose, without spurs; anthers without awns, dehiscent through narrowly oblong, terminal pores; pistil 5–10-carpellate; ovary inferior, 5-locular or 10-locular; stigma capitate. Fruits drupaceous, ovoid to globose, fleshy. Seeds (pyrenes) 10, ellipsoid; testa stony, papillose (smooth in G. ursina). x = 12.
e North America, South America (c), South America (n Andes), South America (e), South America (se Brazil)
Decachaena (Torrey & A. Gray) Lindley; Lasiococcus Small
Species ca. 50 (10 in the flora).
The genus Gaylussacia was organized into three sections by H. Sleumer (1967). The sections are: sect. Vitis-idaea (species 1) with coriaceous, persistent leaves lacking resinous dots; sect. Gaylussacia (species 2–5) with deciduous leaves with some stipitate-glandular hairs; and sect. Decamerium (species 6–10) with deciduous leaves and sessile glands. Molecular investigation by J. W. Floyd (2002) suggested these sections may not be entirely natural, and that the origin of the genus may be in North America, despite the greater diversity in South America.
|1||Leaf blades 1-2.5 cm, margins crenate or serrulate, coriaceous, not sessile-glandular; leaves persistent [sect. Vitis-idaea].||Gaylussacia brachycera|
|1||Leaf blades 1.9-6 cm, margins entire, membranous to subcoriaceous, sessile-glandular (or scattered stipitate-glandular-hairy); leaves deciduous [sect. Gaylussacia]||> 2|
|2||Inflorescence bracts equaling or longer than pedicels, persistent; sepals, pedicels, bracts, and/or leaf blades stipitate-glandular-hairy||> 3|
|2||Inflorescence bracts shorter than pedicels, early-deciduous; sepals, pedicels, bracts, and/or leaf blades not stipitate-glandular-hairy [sect. Decamerium]||> 6|
|3||Corollas 3-5 mm; plants 1-3(-4) dm.||Gaylussacia dumosa|
|3||Corollas 5.5-8.5 mm; plants 3-10(-15) dm||> 4|
|4||Corollas 5.5-6.5 mm; anthers 2.5-3.2 mm; peaty montane seepage bogs, w North Carolina.||Gaylussacia orocola|
|4||Corollas 6.5-8.5 mm; anthers 2.5-4.3 mm||> 5|
|5||Adaxial leaf surfaces not sessile-glandular; ovary hairs 1-1.5 mm; e Gulf coastal plain, s Alabama, n Florida, sw Georgia, se Louisiana, s Mississippi.||Gaylussacia mosieri|
|5||Adaxial leaf surfaces sessile-glandular; ovary hairs 0.3-0.5 mm; northeastern range, south to Maryland and Delaware, disjunct to North Carolina and South Carolina||Gaylussacia bigeloviana|
|6||Leaf blades sessile-glandular-hairy on both surfaces; racemes 0.5-1.5 cm.||Gaylussacia baccata|
|6||Leaf blades sessile-glandular hairy on abaxial surface only; racemes 0.7-4.5 cm||> 7|
|7||Leaf blades membranous, green to yellowish green or reddish green adaxially, apex acute to acuminate.||Gaylussacia ursina|
|7||Leaf blades subcoriaceous, green to glaucescent adaxially, apex rounded or obtuse||> 8|
|8||Twigs of current season glabrous or glabrate; leaf blades glabrous or hairy abaxially, glaucescent; plants 7.5-20 dm; east coast, south to e Georgia.||Gaylussacia frondosa|
|8||Twigs of current season densely hairy (hairs short); leaf blades sparsely to densely hairy abaxially, glaucous or glaucescent; plants 2-20 dm; se North Carolina and southward in coastal plain and west to Louisiana||> 9|
|9||Leaf blades 2.5-4 × 1-2 cm, surfaces glabrous or sparsely short-hairy (longer hairs ca. 0.1 mm), glaucous abaxially; calyces glaucous; plants 2-6(-10) dm.||Gaylussacia nana|
|9||Leaf blades 2.5-6 × 2-3 cm, surfaces densely short-hairy (longer hairs ca. 0.2 mm), glaucescent abaxially; calyces not glaucous; plants 7.5-20 dm.||Gaylussacia tomentosa|
"entire" is not a number.