Click the number at the start of a key lead to highlight both that lead and its corresponding lead. Click again to show only the two highlighted leads. Click a third time to return to the full key with the selected leads still highlighted.
1 Tendrils simple; bark adherent (on all but the largest stems), with prominent lenticels; pith continuous through nodes; leaves relatively small (< 10 cm long and wide) and coarsely toothed, pentagonal in outline but never deeply lobed | |
1 Tendrils bifid to trifid; bark shedding, the lenticels inconspicuous; pith interrupted by diaphragms at nodes; leaves relatively large (well-developed leaves usually > 10 cm wide and long) and finely toothed, often deeply lobed. | |
2 Flowers functionally unisexual; berries globose (isodiametric); berry with skin separating from pulp; [native, collectively widespread]. | |
3 Mature leaves glaucous beneath (the glaucescence sometimes rather obscured by pubescence); nodes often glaucous; inflorescence rachis (flowering and young-fruiting) orange-red arachnoid-pubescent; [series Aestivales]. | |
5 Twigs and petioles rusty-tomentose. | |
6 Mature 3-4-seeded berries 9-14 mm in diameter; [east of the Mississippi River] | |
12 Leaves reniform (wider than long when flattened), folded along the midvein (V-shaped); leaf lower surface glabrous at maturity; tendrils either absent, or when present, only opposite the uppermost nodes (or sometimes extending down the stem); inflorescence rachis (flowering or early-fruiting) glabrous or glabrescent; [series Ripariae] | |
12 Leaves cordate to cordate-ovate (about as wide as long, or longer than wide), not prominently folded along the midvein (near planar); leaf surface glabrous to pubescent at maturity; tendrils present opposite most nodes; inflorescence rachis (flowering or early-fruiting) glabrous, glabrescent, hispid, or white-floccose. | |
13 Nodal diaphragms < 1 mm wide, usually < 0.5 mm wide; growing shoot tips enveloped by enlarging, unfolded leaves; inflorescence rachis (flowering or early-fruiting) glabrous or glabrescent; [section Ripariae] | |
13 Nodal diaphragms > 1 mm wide; growing shoot tips not enveloped by enlarging, unfolded leaves; inflorescence axis (flowering or early-fruiting) hispid and/or white-floccose. | |
15 Nodal diaphragms < 2.5 mm wide; leaves unlobed or shallowly lobed, the tips acute to short-acuminate; branchlets of the season gray, green, or brown (sometimes purple only on one side) | |
14 Branchlets of the season angled, arachnoid-pubescent and/or hirtellous-pubescent (or nearly glabrous); mature 3-4 seeded berries < 8 mm in diameter; nodes frequently banded with red pigmentation; inflorescence rachis (flowering or early-fruiting) white-floccose (and sometimes also hispid); [series Cinerescentes]. | |
16 Branchlets of the season sparsely to densely hirtellous pubescent, often with arachnoid pubescence as well; leaf undersurfaces usually more-or-less uniformly hirtellous on the veins; [western, east to w. KY, w. TN, sc. AL, and Panhandle FL] | |
16 Branchlets of the season lacking evident hirtellous trichomes (if present, obscured by the arachnoid pubescence; leaf undersurfaces lacking hirtellous pubescence, or only very sparsely so; [collectively widespread in our area]. | |