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..2 Leaves 1-2 (-4) cm long, 0.11-0.3 (-0.5) mm wide, each with > 40 terete lobes; plant white or silvery-gray; inflorescence an involucrate head |
..2 Leaves longer and/or wider, with a few to many flattened (< 30) lobes; plant green; inflorescence various, but not as above. |
....3 Leaves > 6× as long as wide, the 14-30 lateral lobes evenly arrayed from leaf base to leaf apex; fresh plants strongly aromatic; leaf surfaces dotted with golden-yellow glands, and also pubescent |
....3 Leaves < 4× as long as wide, the 2-12 lateral lobes either evenly arrayed from leaf base to leaf apex, or strongly basally oriented; fresh plants not aromatic; leaf surfaces variously pubescent, but lacking golden-yellow glands. |
......4 Leaf blades 4-30 cm long; leaf lobing evenly from base to apex, or predominantly towards the tip of the leaf; flowers small, in catkins |
......4 Leaf blades 2-7 cm long; leaf lobing predominantly basal (hastate, or with larger basal lobes becoming smaller and more like serrations towards the apex); flowers larger, in various diffuse inflorescences. |
........5 Leaves hastate, with 2 acute basal lobes, merely serrate towards the apex; [alien species, of s. GA southward] |
........5 Leaves lobate towards base, the lobes rounded in outline, progressively less lobed towards the apex, becoming doubly serrate upwards; [native and alien species, collectively widespread] |
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..........6 Leaves even-pinnately lobed, with 4 (or sometimes 6 or 8) lobes, the apex a very broad V-notch or truncate |
..........6 Leaves odd-pinnately lobed, with 3, 5, 7, etc. lobes (or sometimes with 2 lobes, but one obviously central and the other smaller and to the side, mitten-like), the apex obtuse to acute. |
............ 7 Leaf lobe margins entire. |
............ ..8 Leaves deeply 2- or 3-lobed (or rarely with 1-4 additional very small, tooth-like lobes towards the base), most branches with a mixture of unlobed, 2-lobed (mitten), and 3-lobed leaves; fruit a blackish-seeded drupe; fresh plants strongly aromatic |
............ ..8 Leaves shallowly or deeply 3-25-lobed; fruit either an acorn or a rather fleshy spherical multiple fruit; fresh plants not aromatic. |
............ ....9 Leaves shallowly or deeply 3-25-lobed; fruit a nut in a cupule (an acorn) |
............ ....9 Leaves shallowly 3-lobed (or mostly unlobed); fruit a rather fleshy multiple fruit |
............ 7 Leaf lobe margins serrate. |
............ ......10 Leaves irregularly toothed, the teeth tipped by a soft bristle; fruit a nut in a cupule (an acorn); small to large trees |
............ ......10 Leaves evenly and rather finely serrate, not bristly-tipped; fruit at least somewhat fleshy, either a pome or a multiple of nutlets surrounded by a fleshy calyx; small trees. |
............ ........11 Petals absent (the individual flowers inconspicuous and aggregated into catkins); fruit a multiple, of nutlets surrounded by a fleshy calyx (mulberry) or a syconium (fig); leaves mainly larger, at least some on a branch > 8 cm long |
............ ........11 Petals 5, conspicuous, white or pink; fruit a pome; leaves mainly small, generally < 8 cm long |
1 Ovary inferior; fruit indehiscent (pome). |
..2 Upper surface of leaves bearing dark glandular trichomes along the midrib (most easily seen with a 10× hand lens); shrubs |
..2 Upper surface of leaves lacking dark glandular trichomes along the midrib; shrubs and trees. |
....3 Ovary and fruit 10-locular; inflorescence a raceme (rarely a fascicle); pome < 1 cm in diameter |
....3 Ovary and fruit 5-locular; inflorescence a cyme, umbel, or fascicle (lacking an elongated central axis); pome 0.7-10 cm in diameter. |
......4 Styles distinct; exocarps (carpels within pericarp) bony and seedlike; trees and shrubs, with thorns |
......4 Styles usually connate at base; exocarps leather or papery and easily opened to expose seeds; small trees, unarmed, or armed with sharp spur branches. |
........5 Pome globose to ovoid, lacking stone cells; anthers yellow to white; styles connate at the base; leaves blunt to acuminate; [apples and crabapples] |
........5 Pome globose or pyriform, with stone cells; anthers reddish; styles distinct; leaves acute to acuminate; [pears] |
1 Ovary superior; fruit dehiscent (aggregate of follicles, or capsule) or indehiscent (drupe, aggregate of drupelets, aggregate of achenes). |
..........6 Leaves opposite; fruit an aggregate of usually 3-5 purple to black drupelets; [tribe Kerrieae] |
..........6 Leaves alternate; fruit various (see below; if an aggregate of drupelets, then with >5 drupelets). |
............ 7 Leaves large, > 10 cm wide, palmately veined, palmately lobed; fruit an aggregate of drupelets; [tribe Rubeae] |
............ 7 Leaves smaller, < 8 cm wide, pinnately veined, either not lobed or basally pinnately lobed; fruit a drupe, a capsule, an aggregate of follicles, or an aggregate of achenes. |
............ ..8 Leaves singly serrate or entire (rarely, as in Prunus americana, irregularly and slightly doubly serrate), not lobed basally. |
............ ....9 Gynoecium of separate carpels; fruit an aggregate of follicles; [tribe Spiraeeae] |
............ ....9 Gynoecium of fused carpels; fruit either a fleshy drupe or a capsule. |
............ ......10 Ovary 5-angled in ×-section; fruit a 5-angled capsule; leaves obovate, obviously broadest towards the tip; [tribe Osmaronieae] |
............ ......10 Ovary circular in ×-section; fruit a fleshy spherical drupe; leaves generally broadest near or below the middle; [tribe Amygdaleae] |
............ ..8 Leaves doubly serrate, also often lobed towards the base. |
............ ........11 Corolla yellow; stems arching, green; fruit an aggregate of drupe-like achenes (dry and indehiscent); [tribe Kerrieae] |
............ ........11 Corolla white to pink or rose; stems not both arching and green; fruit various (see below). |
............ ..........12 Inflorescence a dense, umbel-like corymb; leaf apices rounded to acute; fruit an aggregate of 5 follicles; [tribe Neillieae] |
............ ..........12 Inflorescence a raceme or a leafy panicle; leaf apices acuminate. |
............ ............ 13 Fruit a single follicle; [alien, planted, and rarely naturalized, as in e. VA]; [tribe Neillieae] |
............ ............ 13 Fruit an aggregate of 2-4 drupe-like achenes; [rare native of calcareous habitats in sc. TN, nw. GA, n. AL, and disjunct westward in AR and MO]; [tribe Kerrieae] |