Perennials, root tuberlike. Stems usually trailing, some­times twining near tips. Leaf blades orbiculate, palmatisect, lobes 5–9, lanceolate to linear, 10–70 × 0.5–6.5 mm, surfaces glabrous. Peduncles glabrous. Flowers nocturnal; sepals char­taceous or coriaceous, outers oblong-lanceolate, 5–12 × 2–3 mm, muricate along mid­rib or ± smooth, margins scarious, apex mucronate, inners obovate-acuminate, 8–9 × 3–4 mm, smooth, mar­gins scarious; corolla white, limb sometimes purple or pale rose-red, funnelform or salverform, 35–100 mm, limb 30–36 mm diam.

Distribution

sc, sw United States, n Mexico.

Discussion

Varieties 2 (2 in the flora).

The two varieties of Ipomoea tenuiloba are com­paratively easy to distinguish; there are intergrades (G. Yatskievych and C. T. Mason 1984), some approach­ing I. plummerae.

Selected References

None.

Lower Taxa

Ipomoea tenuiloba var. lemmonii, Ipomoea tenuiloba var. tenuiloba

Key

1	Leaf blade lobes 5–7, each to 1.2 mm wide; corollas usually white, limb sometimes pink to lavender, salverform, 65–100 mm; filaments: free portions 8–11 mm.	Ipomoea tenuiloba var. tenuiloba
1	Leaf blade lobes 7–9, each to 6.5 mm wide; corollas: tube white, limb purple to red, fun­nelform, 35–65 mm; filaments: free portions 14–19 mm.	Ipomoea tenuiloba var. lemmonii