Calystegia occidentalis

Perennials or subshrubs, root­stock woody. Herbage usually puberulent or pubescent, some­times glabrescent, rarely tomen­tellous or ± villous. Stems decumbent, procumbent, or twining-climbing, to 400 cm. Leaves: blade ± triangular, 15–40 mm, base usually lobed, lobes rounded or 1–2-pointed, basal sinus quadrate, rounded and ± parallel-sided, or V-shaped, base sometimes ± cuneate. Bracts (1–)3–12(–15) mm distant from sepals, lanceolate, linear, linear-oblong, oblanceolate, or narrowly to broadly triangular, 4–22(–30) × 1–4(–7) mm, margins entire or proximally lobed or toothed. Flowers: sepals 9–15 mm; corolla white or cream, (20–)25–48 mm.

Distribution

w United States.

Discussion

Subspecies 2 (2 in the flora).

Subspecies occidentalis and subsp. fulcrata are dis­tinguished essentially by entire versus proximally lobed or toothed bract margins; the distinction is not absolute.

Selected References

None.

Lower Taxa

Calystegia occidentalis subsp. fulcrata, Calystegia occidentalis subsp. occidentalis

Key

1	Peduncles (1–)2–4-flowered; bract margins entire.	Calystegia occidentalis subsp. occidentalis
1	Peduncles 1-flowered; bract margins proximally lobed or toothed.	Calystegia occidentalis subsp. fulcrata