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1 Herbage softly and densely white-woolly; [rare escapes and persistents from cultivation]. |
..2 Perennial; leaf blades heavily lanate, narrowed to the base, the dentations (if any) concealed by the felt; calyx lobes concealed by tomentum |
..2 Biennial; leaf blades silky-pilose or tomentose, rounded to cordate at the base, obviously dentate; calyx lobes projecting beyond the pubescence |
1 Herbage variously pubescent or glabrous, but never white-woolly; [collectively common, both natives and aliens]. |
....3 Annuals from fibrous roots, typically freely branching from the base or from lower nodes; leaf blades 1-5 cm long, with rounded or obtuse apices (except acute to acuminate in S. annua); [aliens, except S. agraria]. |
......4 Leaves cuneate at base, acute to acuminate at tip; corolla 10-16 mm long (well exceeding the calyx), white to yellow |
......4 Leaves cordate or truncate at base, rounded or obtuse at tip; corolla 4-9 mm long (barely or not exceeding the calyx), white to pink. |
........5 Calyx 3-5 mm long; corolla 4-6 mm long |
........5 Calyx 7-9 mm long; corolla 7-9 mm long |
....3 Perennials from rhizomes, not branching in the lower portion (unless damaged); leaf blades often > 5 cm long, with acute apices; [natives, except S. floridana and S. palustris]. |
..........6 Petioles (at least some of those of the principal stem leaves) > 1/5 as long as the blades. |
............ 7 Calyx strongly glandular with atomiferous glands or gland-tipped hairs, or both. |
............ ..8 Calyx lobes narrowly lanceolate, about as long as the calyx tube; leaf blades lance-ovate to lanceolate, < 3 cm wide; stem angles glabrate to short retrorse pubescent; root tips with moniliform tubers; [native and weedy species, mostly of the Coastal Plain] |
............ ..8 Calyx lobes deltoid to deltoid-lanceolate, shorter than the calyx tube; leaf blades broadly cordate-ovate, usually > 3 cm wide; stem angles hispid; roots without tubers; [native species of rich mountain forests]. |
............ ....9 Calyx lobes aristate, with a linear tip 1-2 mm long. |
............ ......10 Stem faces eglandular; stem angles with spreading trichomes 1–3 mm long; leaves sparingly pubescent |
............ ......10 Stem faces copiously atomiferous glandular; stem angles with pustulate based spreading trichomes 1–3 mm long; leaves atomiferous glandular mixed with sparse eglandular trichomes |
............ ....9 Calyx lobes angles or with linear portion < 1 mm long. |
............ ........11 Calyx lobes deltoid; leaves broadly rounded with a cordate base and crenulate margins |
............ ........11 Calyx lobes deltoid-lanceolate; leaves various. |
............ 7 Calyx sparsely glandular or eglandular. |
............ ..........12 Leaves ovate to broadly ovate, deeply cordate at base |
............ ..........12 Leaves oblong, lanceolate, elliptic, or ovate-elliptic, not cordate or only slightly so. |
............ ............ 13 Calyx hispidulous to strongly hispid with long, stiff, deflexed hairs; stem moderately to densely pubescent on the angles with hairs to 3 mm; leaves usually pubescent above (some forms glabrate); petioles rarely as much as 1-2 cm long |
............ ............ 13 Calyx glabrous to moderately pubescent with short, soft hairs; stem glabrous to moderately pubescent on the angles; leaves sparsely pubescent or glabrate; petioles well developed (1-3 cm long), especially in shade forms. |
............ ............ ..14 Leaf blades wider, ovate-oblong to elliptic; calyx lobes deltoid-acuminate to an apiculate tip, ½ to 2/3 as long as the calyx tube; bracts of the inflorescence usually conspicuous and only gradually reduced upward; plants generally more pubescent |
............ ............ ..14 Leaf blades oblanceolate, oblong, or narrowly elliptic; calyx lobes lanceolate, usually recurved-spreading in fruit, about as long as the calyx tube; bracts of the inflorescence inconspicuous, rapidly reduced upward; plants generally glabrate |
..........6 Petioles < 1/5 as long as the blade or absent. |
............ ............ ....15 Stem below the inflorescence pubescent on the sides, as well as the angles. |
............ ............ ......16 Calyx lobes lanceolate, more than half as long as the tube; leaf blades velvety-pubescent; flowers 6 per verticil. |
............ ............ ........17 Stem hairs spreading; leaf blades strongly velvety-pubescent; corolla pink |
............ ............ ........17 Stem hairs strongly reflexed; leaf blades slightly velvety-pubescent; corolla purple |
............ ............ ......16 Calyx lobes deltoid, no more than half as long as the calyx tube; leaf blades pubescent but never velvety; flowers 8 or more per verticil. |
............ ............ ..........18 Leaf blades oblong/lanceolate; lowest leaves obtuse at apex; leaves < 3 cm broad; corolla white; [restricted to Santee River delta SC] |
............ ............ ..........18 Leaf blades elliptic/ovate; lowest leaves acute at apex; leaves up to 5 cm broad; corolla pink; higher elevations, [of the Appalachians, etc.]. |
............ ............ ............ 19 Calyx lobes strongly deltoid; stem and abaxial leaf surface densely atomiferous glandular and with few eglandular hairs |
............ ............ ............ 19 Calyx lobes deltoid-lanceolate; stem and abaxial leaf surface moderately glandular and with frequent soft eglandular hairs |
............ ............ ....15 Stem below the inflorescence glabrous on the sides (rarely with a few remote hairs and/or glands) or atomiferous-glandular only. |
............ ............ ............ ..20 Leaves linear-lanceolate to lanceolate or lance-elliptic, often widest below the middle, 3-15 (-20) mm wide; leaf margins entire to crenulate or serrulate. |
............ ............ ............ ....21 Leaf blades very narrow, 3-6 (-10) mm wide, the margins entire to obscurely crenulate; herbage glabrous to moderately pubescent |
............ ............ ............ ....21 Leaf blades broader, 5-15 (-19) mm wide, the margins crenulate to finely serrate; herbage hispidulous to strongly pubescent |
............ ............ ............ ..20 Leaves ovate-oblong to elliptic, usually widest near the middle, (1.6-) 2.0-5.0 (-6.0) cm wide; leaf margins crenate to sharply serrate. |
............ ............ ............ ......22 Stem (including the sides) and usually the leaves with minute but copious atomiferous glands |
............ ............ ............ ......22 Leaves and stem eglandular or with a few scattered glands. |
............ ............ ............ ........23 Mature calyx lobes triangular deltoid and abruptly apiculate, less than half as long as the calyx tube. |
............ ............ ............ ..........24 Leaf margins serrulate or serrate; stem nodes not bearded (sometimes obscurely fine-hairy); stem angles with scattered, pustulate, short deflexed hairs; [high-elevation montane habitats] |
............ ............ ............ ..........24 Leaf margins crenulate or crenate; stem nodes bearded; lower stem angles copiously pubescent with 3-celled spreading hairs; [low-elevation Piedmont and Coastal Plain habitats] |
............ ............ ............ ........23 Mature calyx lobes lanceolate or deltoid-acuminate to an apiculate tip, more than half as long as the calyx tube. |
............ ............ ............ ............ 25 Calyx sparsely to moderately pubescent with short, soft hairs; stem angles moderately pubescent to nearly glabrous; leaves sparsely pubescent or glabrate; principal leaves on petioles 1 to 3 cm long; bracts of the inflorescence usually conspicuous and only gradually reduced upward, the cilia ± incurved-ascending |
............ ............ ............ ............ 25 Calyx hispidulous to strongly hispid with long, stiff hairs; stem angles moderately to densely pubescent; leaves usually pubescent above (some forms glabrate); principal leaves usually subsessile, with very short petioles; bracts of the inflorescence usually inconspicuous and rapidly reduced upward; if conspicuous, bracts ciliate with long, stiffly spreading hairs. |
............ ............ ............ ............ ..26 Calyx flaring at maturity, conspicuously glandular with long stipitate trichomes and shorter sessile and subsessile glandular hairs; stem faces with occasional glandular and/or eglandular trichomes |
............ ............ ............ ............ ..26 Calyx erect at maturity, sparsely short glandular to eglandular; stem faces usually with a few atomiferous glands only |