Calystegia spithamaea
Fl. Amer. Sept. 1: 143. 1813.
IllustratedEndemic
Basionym: Convolvulus spithamaeus Linnaeus Sp. Pl. 1: 158. 1753
Treatment appears in FNA Volume 14.
Perennials, rhizomatous. Herbage glabrate or tomentose, hairs sometimes whitish. Stems erect, 10–35(–50) cm. Leaves: blade narrowly to broadly elliptic, to 80 × 35 mm, base cuneate, rounded, or lobed, lobes rounded or ± 1-pointed, to 11 mm. Bracts immediately subtending sepals, lance-ovate, oblong, or oval, (13–)16–25(–29) × 8–14(–20) mm, proximally flat or ± keeled, apex acute to obtuse, closely enfolding sepals. Flowers: sepals 12–17 mm; corolla white, 35–63(–67) mm.
Distribution
c, e North America.
Discussion
Subspecies 3 (3 in the flora).
Selected References
None.
Lower Taxa
Key
1 | Habit ± lax; herbage glabrate to pubescent; leaf blades ultimately ± flat. | Calystegia spithamaea subsp. spithamaea |
1 | Habit ± compact; herbage tomentose, hairs sometimes whitish; leaf blades ± conduplicate. | > 2 |
2 | Leaf blade bases usually lobed, lobes to 5(–6) mm, sometimes cuneate; corollas (38–)43–59(–64) mm; plants (10–)15–35(–40 cm). | Calystegia spithamaea subsp. stans |
2 | Leaf blade bases lobed, lobes 4–11 mm; corollas 35–47(–53) mm; plants (15–)25–35(–40) cm. | Calystegia spithamaea subsp. purshiana |