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1 Largest leaves < 8 mm long; flowers white, yellow, or creamy; plant an annual, 0.5-3 dm tall; [ clade VII]. |
2 Inflorescences terminal and axillary, with pedicels > 5 mm long; [of w. AR, OK, and TX] |
2 Inflorescences axillary, the flowers on pedicels < 2 mm long; [collectively widespread]. |
3 Flowers (1-) 2-3 in small clusters in leaf axils, the pedicels 1-2 mm long; fruits and ovaries glabrous |
3 Flowers solitary, sessile or subsessile in the leaf axils, the pedicels 0.3-0.8 mm long; fruits and ovaries pubescent with hooked hairs. |
4 Flowers about as long as the subtending bracts; stems hispidulous |
4 Flowers shorter than the subtending bracts; stems glabrous |
1 Largest leaves > 8 mm long; flowers white, creamy, greenish-purple, maroon, or purple; plant a perennial, 1-8 dm tall. |
5 Larger leaves 2.5-25 mm wide, mostly 1.5-5 (-8)× as long as wide; fruits uncinate- hispid (except smooth in G. latifolium and G. arkansanum); flowers greenish, purplish, purple-and-cream, or yellow (in G. cruciata); leaves normally of very similar length and forming a symmetrical, neat whorl; [ clade VII]. |
6 Corollas yellow; flowers in axillary inflorescences; corolla tube very short |
6 Corollas greenish, purplish, purple-and-cream; flowers in terminal inflorescences; corolla tube longer. |
7 Leaves widest below the middle, tapering to a long- acuminate apex, averaging about 3-5 (-8)× as long as wide; largest leaves 30-80 mm long, 2.5-20 mm wide. |
8 Fruits uncinate- hispid; flowers yellowish, turning maroon |
8 Fruits smooth; flowers purple. |
9 Leaves with 3-5 (-7) veins from the base, the lateral veins obvious; leaves 13-20 mm wide; [Appalachians] |
9 Leaves with 1-3 veins from base, the lateral 2 veins obscure or absent; leaves 2.5-9 mm wide; [Interior Highlands] |
10 Corollas glabrous on the exterior surface; leaves 5-9 mm wide, 1-3-veined |
10 Corollas densely silky- pubescent on the exterior surface; leaves 2.5-3.5 mm wide and 1-veined |
7 Leaves widest at about the middle, tapering to an obtuse (or broadly acute) apex, averaging about 2-3× as long as wide; larger leaves 10-50 mm long, 5-25 mm wide. |
11 Flowers (some of them) sessile or subsessile along the inflorescence branches; leaves 1.5-5 cm long, the larger usually > 2.5 cm long |
11 Flowers all distinctly pedicelled; leaves 1-2.5 cm long |
12 Stem glabrous; plants sprawling; leaves 2-5× as long as wide |
12 Stem pubescent with either straight or upwardly incurved hairs; plants erect; leaves 1.5-2.5× as long as wide |
5 Larger leaves 1-6 mm wide, mostly 4-20× as long as wide (or 2-3.5× as long as wide in G. bermudense); fruits smooth or pubescent (if pubescent, the hairs not hooked at the end, though they may curve through their length, except uncinate in G. texense), either fleshy or dry; flowers white or creamy; leaves normally of differing lengths and also often forming asymmetrical, 'sloppy' whorls (the angles between the leaves not being 90°). |
13 Fruits fleshy and blue-black; leaves firm, more-or-less evergreen, glandular- punctate beneath; [ clade undetermined]. |
14 Leaves elliptic, 7-18 mm long, 3-6 mm wide, 2-3.5× as long as wide |
14 Leaves linear, 15-25 mm long, 2-4 mm wide, 5-10× as long as wide |
13 Fruits dry, and green, tan, or purplish; leaves herbaceous, deciduous, not glandular- punctate beneath. |
15 Stems erect or nearly so; leaves 15-45 mm long, 2-6 mm wide; [ clade VII] |
15 Stems sprawling, matted (or erect in G. labradoricum); leaves 5-30 mm long, 0.5-5 (-6) mm wide; [ clade V]. |
16 Stems smooth on the angles or with few, scattered hairs; stem nodes densely retrorsely bearded; corollas 4- lobed, the lobes longer than wide; leaves strictly 4 per node (very rarely 5 at a few nodes). |
17 Leaves strongly down-curved when fully grown; leaves 1-2.5 mm wide |
17 Leaves spreading; leaves (0.5-) 0.8-5 (-6) mm wide |
18 Leaves (8-) 10-20 (-25) mm long, (0.5-) 0.8-2 mm wide, margin usually smooth, with strongly down- rolled margins; corolla (1.8-) 2-2.5 (-3) mm across; pedicels filiform; stems 15-50 (-60) cm long, delicate |
18 Leaves (10-) 15-25 (-30) mm long, (2-) 3-5 (-6) mm wide, margin scabrous, not down- rolled; corolla (2-) 2.5-3.5 (-4) mm across; pedicels thicker; stems (15-) 25-60 (-80) cm long, firm |
16 Stems retrorsely scabrous on the angles; stem nodes not conspicuously bearded; corollas 3-4- lobed, the lobes about as wide as long, or wider than long; leaves 4 per node, but most plants with at least some main stem nodes with 5 or 6 leaves. |
19 Flowers and fruits borne on arcuate pedicels, (5-) 7-15 (-20) mm long and densely retrorsely scabrous |
19 Flowers and fruits borne on straight pedicels, these (2-) 2.5-8 (-12) mm long and smooth. |
20 Fruiting pedicels (4-) 5-8 (-12) mm long; pairs of fruits (3-) 3.5-5 mm across at maturity; leaves 2-3 (-4) mm wide |
20 Fruiting pedicels (2-) 2.5-5 (-6) mm long; pairs of fruits 2-3 mm across at maturity; leaves (1.5-) 2-2.5 (-2.8) mm wide |
1 Flowers pink, purple, or blue, in terminal heads, subtended by an involucre of leaves fused at the base; stem rough-hairy or retrorse- scabrid; [ exotic]. |
2 Leaves obtuse at tip; leaves 6-8 per whorl; stem retrorse- scabrid; [ clade VI] |
2 Leaves acute to acuminate at tip; leaves (4-) 6 per whorl; stem rough-hairy; [ clade IV] |
1 Flowers white, yellow, or green, in axillary or terminal diffuse inflorescences, not subtended by an involucre; stems either smooth, retrorse- scabrid, or pubescent. |
3 Largest leaves < 10 mm long; fruits 0.7-1 mm across; annual; [ exotic]; [ clade III]. |
4 Inflorescence relatively diffuse, branches divaricate; ultimate fruits (2-) 3-6 (-7) nodes beyond primary stem axis (with largest leaves); first inflorescence internode (beyond primary stem axis) 15-50 mm long; fruit surface glabrous (without hairs) |
4 Inflorescence relatively strict, branches ascending; ultimate fruits 2-3 (-4) nodes beyond primary stem axis (with largest leaves); first inflorescence internode (beyond primary stem axis) 3-12 (-20) mm long; fruit surface glabrous or bristly- hispid. |
5 Fruit surface without hairs, smooth to shallowly papillate |
5 Fruit surface bristly- hispid with uncinate-tipped hairs, distinctly papillate |
3 Largest leaves > 10 mm long; fruits 1-2.5 mm across; perennial; [native]. |
6 Fruits and ovaries uncinate- hispid; leaves 15-50 mm long, 7-10 mm wide; [ clade III] |
6 Fruits and ovaries glabrous or papillose; leaves 5-25 mm long, 1-6 mm wide. |
7 Corolla 1.5-2.5 mm across, 3- lobed; [collectively widespread in our area]; [ clade V]. |
8 Fruiting pedicels (4-) 5-8 (-12) mm long; pairs of fruits (3-) 3.5-5 mm across at maturity; leaves 2-3 (-4) mm wide |
8 Fruiting pedicels (2-) 2.5-5 (-6) mm long; pairs of fruits (2-) 2.5-3 mm across at maturity; leaves (1.5-) 2-2.5 (-2.8) mm wide |
7 Corolla 2.5-4.5 mm across, 4- lobed; [mostly of the Mountains in our area, extending into the Piedmont or even the Coastal Plain in n. VA and northward]; [ clade undetermined]. |
9 Leaf margins retrorsely ciliate- scabrid; leaves 3-5× as long as wide; [plants of bogs and moist thickets] |
9 Leaf margins antrorsely ciliate- scabrid; leaves 4-8× as long as wide; [plants of dry forests and woodlands]. |
10 Leaves sharply acute or cuspidate; corolla 2.5-3 mm across |
10 Leaves rounded, obtuse, or barely acute; corolla ca. 4 mm across |