Convolvulaceae

Annuals, perennials, subshrubs, shrubs, vines, or lianas [trees], some with milky sap; Cuscuta parasitic, achlorophyllous. Stems decumbent, erect, procumbent, repent, trailing, or twining-climbing. Leaves alternate, usually simple, sometimes compound; stipules absent; petiole present or absent; blade margins entire, toothed, or lobed. Inflorescences axillary, ± cymose or flowers solitary; bracteate or not; bracteolate or not. Flowers bisexual [unisexual], actinomorphic or weakly zygomorphic; calyx persistent, sepals 5, distinct or proximally connate, equal or unequal; corolla blue, cream, green, lavender, maroon, pink, purple, rose, violet, white, or yellow, campanulate, funnelform, rotate, salverform, tubular, or urceolate, limb (3–)5-lobed or -toothed or entire, induplicate, sometimes also convolute, in bud; nectary annular or cup-shaped, sometimes 5-lobed or absent; stamens (3–)5, distinct, filaments inserted on corolla tube, anthers 2-celled, linear or oblong, dehiscent by slits; ovary superior, 1–4(–6)-locular, placentation basal or basal-axile, ovules 1–6 per locule, anatropous, bitegmic, crassi- or tenuinucellate; styles 1 or 2; stigmas 1 or 2, capitate, globose, peltate, or 2(–4)-lobed. Fruits usually capsular, sometimes berrylike (nutlike), dehiscent or indehiscent. Seeds 1–4(–6), black, brown, green, or yellow, ellipsoid, globose, obcompressed, or pyramidal, glabrous or hairy; endosperm absent or scant, cartilaginous; embryo straight, cotyledons usually folded, rarely absent.

Distribution

nearly worldwide.

Discussion

Genera 56, species 1600–1700 (18 genera, 167 species in the flora).

A traditional circumscription of Convolvulaceae, including Cuscuta and Dichondra, is followed here. Cuscuta is sometimes treated as a distinct family, Cuscutaceae Dumortier, and, less commonly, Dichondra has been treated in a distinct family, Dichondraceae Dumortier (A. Cronquist 1981; A. B. Rendle 1959).

In addition to hundreds of horticultural cultivars, economically important members of Convolvulaceae include Ipomoea batatas (sweet potato) and species of Calystegia that are agricultural weeds. Some species of Convolvulaceae are sources of hallucinogens and medicines, especially purgatives.

Selected References

None.

Lower Taxa

Aniseia, Argyreia, Bonamia, Calystegia, Convolvulus, Cressa, Cuscuta, Dichondra, Evolvulus, Ipomoea, Jacquemontia, Merremia, Operculina, Petrogenia, Poranopsis, Stictocardia, Stylisma, Turbina

Illustrations

Convolvulaceae Illustrations

Key

1	Plants parasitic (lacking chlorophyll).	Cuscuta
1	Plants not parasitic (autotrophic).	> 2
2	Stems usually ascending, creeping, decumbent, erect, procumbent, prostrate, or trailing, seldom twining-climbing; leaves: larger blades 10–30(–100) mm; styles usually 2 (1 in Convolvulus).	> 3
3	Stigmas or stigma lobes cylindric, linear, filiform, subclavate, subulate, or spatulate.	> 4
4	Leaves sessile or subsessile; styles 2, stigma lobes 4, filiform to subclavate.	Evolvulus
4	Leaves usually petiolate, rarely sessile; styles 1, stigma lobes 2, cylindric, linear, or spatulate.	Convolvulus (in part)
3	Stigmas capitate, globose, or peltate.	> 5
5	Styles: insertion ± basal; fruits subglobose to ± compressed, ± incised and 2-lobed, indehiscent or shattering irregularly.	Dichondra
5	Styles: insertion not ± basal; fruits conic, fusiform, globose, oblong-ovoid, or ovoid, dehiscence valvate.	> 6
6	Leaf blades 1–14 mm.	> 7
7	Stems decumbent to erect, seldom, if ever, mat-forming; corollas salverform, white, 5–7 mm.	Cressa
7	Stems decumbent, erect, prostrate, or trailing, sometimes mat-forming; corollas ± campanulate, greenish yellow to yellow, 3–4 mm.	Petrogenia
6	Leaf blades (1–)10–60(–100).	> 8
8	Sepals 9–28 mm; corollas blue, blue-purple, or white with blue limb, 35–85 mm.	Bonamia
8	Sepals 4–11 mm; corollas usually white, sometimes lavender, maroon, pink, purple, or red, 8–25 mm.	Stylisma
2	Stems usually twining-climbing, sometimes repent or trailing, rarely almost absent, ascending, decumbent, erect, or procumbent; leaves: larger blades (10–)40–270 mm; styles 1.	> 9
9	Fruits indehiscent.	> 10
10	Sepals lanceolate-linear, 1–2 mm; corollas white, to 8 mm.	Poranopsis
10	Sepals elliptic, oblong, or ovate to orbiculate, 7–20 mm; corollas lavender, purple, purplish red, red, white, or yellow, 25–95 mm.	> 11
11	Leaf blade abaxial surfaces black-glandular-punctate; fruits dry, 25–30 mm.	Stictocardia
11	Leaf blade abaxial surfaces glabrous, glabrate, or white-hairy; fruits fleshy or dry, 10–15 mm.	> 12
12	Leaf blades 180–270 mm; sepals ovate, 15–20 mm; corollas lavender, 60–65 mm; fruits berrylike, fleshy.	Argyreia
12	Leaf blades 40–100 mm; sepals oblong, 7–12 mm; corollas proximally purplish, distally ± white with greenish bands, 25–40 mm; fruits capsular or nutlike, dry.	Turbina
9	Fruits dehiscent.	> 13
13	Stigmas or stigma lobes cylindric, elliptic, linear, oblong, reniform, spatulate, or subulate.	> 14
14	Stems hairy, hairs usually branched, glandular, and/or stellate, sometimes simple.	Jacquemontia
14	Stems glabrous or hairy, hairs not branched, glandular, or stellate.	> 15
15	Sepals (5–)8–15(–25) mm; ovary 1-locular; stigma lobes linear to oblong, apices blunt.	Calystegia
15	Sepals 3–12 mm; ovary 2-locular; stigma lobes cylindric to spatulate, apices acute.	Convolvulus (in part)
13	Stigmas or stigma lobes capitate or globose.	> 16
16	Fruit dehiscence circumscissile.	Operculina
16	Fruit dehiscence irregular or valvate.	> 17
17	Anthers twisted after dehiscence; pollen usually 3–9-colpate, rarely aggrecolpate, not echinate.	Merremia
17	Anthers straight after dehiscence; pollen rugate and not echinate (Aniseia) or pantoporate and echinate (Ipomoea).	> 18
18	Sepals notably accrescent in fruit, outer 3 notably longer than inner 2; corolla white, campanulate, 25–30 mm.	Aniseia
18	Sepals seldom notably accrescent in fruit, outer 3 not notably longer than inner 2; corolla usually blue, lavender, pink, purple, red, violet, or white, sometimes orange, red and yel­low, or red-orange, usually funnelform, sometimes campanulate or salverform, (6–)20–80(–150+) mm.	Ipomoea