Calystegia collina

(Greene) Brummitt

Ann. Missouri Bot. Gard. 52: 215. 1965.

Endemic
Basionym: Convolvulus collinus Greene Pittonia 3: 326. 1898
Synonyms: C. malacophyllus subsp. collinus (Greene) Abrams
Treatment appears in FNA Volume 14.

Perennials, rhizomatous. Herb­age tomentellous, tomen­tose, or villous. Stems ascending-decumbent, to 50 cm, sometimes almost absent. Leaves in basal rosettes; blade usually triangular, sometimes notably 3-lobed, to 40 mm, base ± lobed, lobes oblong to triangular, 1–3-pointed, margins ± undulate or not, apex rounded to acute. Bracts immediately subtending sepals, lanceolate, linear-elliptic, or ovate, 5–17 × 1.5–14 mm. Flowers: sepals 8–13 mm; corolla white, (25–)27–50(–55) mm.

Discussion

Subspecies 5 (5 in the flora).

Selected References

None.

Key

1 Leaf blades notably 3-lobed, lobes oblong to triangular, margins not notably undulate; bracts 1.5–3.5 mm wide. Calystegia collina subsp. tridactylosa
1 Leaf blades triangular, usually basally lobed and lobes 1–3-pointed, weakly lobed in subsp. collina, margins undulate or not; bracts 4–14 mm wide. > 2
2 Sepals glabrous or medially strigose. > 3
3 Leaf blades ± triangular, base weakly lobed, lobes seldom well developed, apex rounded to subacute. Calystegia collina subsp. collina
3 Leaf blades broadly triangular, basal lobes well developed, apex acute. Calystegia collina subsp. oxyphylla
2 Sepals, at least outers, hairy, hairs appressed. > 4
4 Leaf blades mostly 40 × 40 mm, margins not undulate. Calystegia collina subsp. apicum
4 Leaf blades mostly 10–20 × 10–20 mm, margins undulate. Calystegia collina subsp. venusta