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1 Leaves tiny, bract-like, triangular, 6-14 (-17) per node |
1 Leaves either needle-like, scale-like, or flattened and large, (2-) 3-4 (-6) per node. |
..2 Leaves needle-like or scale-like, terete, angled, or flat in ×-section, < 2 cm long; leaves (2-) 3-4 (-6) per node |
..2 Leaves flat, > 3 cm long; leaves (2-) 3 per node; [Eudicots]. |
....3 Plant a subshrub, < 3 dm tall, with < 10 leaves per stem. |
......4 Leaves entire, broadly elliptic; flowers numerous, in a hemispherical head, subtended by 4 large white bracts |
......4 Leaves serrate, narrowly ovate or narrowly obovate; flowers (1-) 2-8 in a long-peduncled umbel or corymb, not subtended by bracts |
....3 Plant a shrub or tree, > 3 dm tall, with many > 10 leaves per stem. |
........5 Leaves toothed, and most leaves also lobed |
........5 Leaves entire, not lobed. |
..........6 Leaves cordate at base; leaves about as long as wide; medium to large tree. |
............ 7 Flowers white to yellow; capsules linear, >10× as long as wide; leaf undersurface with curly simple hairs; nectar glands present in the main vein axils on the undersurface of the leaf (visible from the underside or the upperside in fresh leaves and herbarium specimens as a triangle 1-4 mm on a side) |
............ 7 Flowers lavender; capsules ellipsoid, < 2× as long as wide; leaf undersurface with branched (dendritic or stellate) hairs; nectar glands absent |
..........6 Leaves cuneate to rounded at base; leaves > 1.5× as long as wide; shrub to small tree. |
............ ..8 Leaves rounded at the tip |
............ ..8 Leaves acute to acuminate at the tip. |
............ ....9 Leaves lanceolate or oblong-elliptic (> 2.5× as long as wide), the secondary venation not prominent; inflorescences axillary or terminal; flowers pink or white. |
............ ......10 Inflorescences axillary; flowers pink; leaves thin and herbaceous; [native plants of wetlands] |
............ ......10 Inflorescences terminal or axillary; flowers pink or white; leaves thick and leathery; [exotics of uplands or wetlands, persistent or weakly naturalized] |
............ ........11 Fruit berry-like with 2-locular ovaries; flowers white-colored, smaller; inflorescence axillary or pseudo-terminal; leaves opposite to whorled |
............ ........11 Fruit follicles; flowers variously colored, showy and salverform; inflorescence terminal; leaves alternate to whorled (pseudo-whorled) |
............ ....9 Leaves ovate (< 2× as long as wide), the secondary venation prominent and arching-parallel; inflorescences terminal; flowers white, greenish-yellow, red, or orange. |
............ ..........12 Flowers in a spherical or hemispherical head; corollas white or greenish-yellow |
............ ..........12 Flowers in a monochasial helicoid cyme; corollas red to orange |