Description from Flora of China
Herbs or shrubs, usually with twining or climbing stems or erect, often with milky juice. Leaves alternate, simple, entire, dissected, or compound, absent in parasitic species. Flowers solitary, axillary or in cymes, racemes, panicles, umbels, or capitula, bisexual, actinomorphic, usually 5-merous, often showy. Sepals free, often persistent, sometimes enlarged in fruit. Corolla sympetalous, funnelform, campanulate, salverform, or urceolate; limb subentire or deeply lobed. Stamens alternating with corolla lobes, adnate to corolla; filaments filiform, equal or unequal in length; anthers introrse, laterally and longitudinally dehiscing; pollen smooth or finely spiny. Disc ringlike or cupular. Ovary superior, mostly 2-carpellate, 1- or 2-loculed, rarely 3- or 4-loculed; ovules basal, erect. Styles 1 or 2, terminal (gynobasic in Dichondra) or very short or absent; stigma entire or 2- (or 3)-lobed, rarely peltate. Fruit a capsule, dehiscing by valves, circumscissile, or irregularly shattering, less often a berry or nutlike. Seeds usually trigonous, smooth or pubescent.
About 58 genera and 1650 species: widely distributed in tropical, subtropical, and temperate regions; 20 genera and 129 species in China.
Aniseia biflora (Linnaeus) Choisy and A. stenantha (Dunn) Ling, recognized in the Fl. Reipubl. Popularis Sin., are here treated as Ipomoea biflora and I. fimbriosepala, respectively, because both have pantoporate and spinulose pollen. Strictly speaking, Aniseia is a neotropical genus of about five species, of which A. martinicensis (Jacquin) Choisy is widely naturalized as a common weed in rice paddies in Thailand and other southeast Asian countries. It will probably be found in S China eventually.
The family is important in China for food plants (Ipomoea batatas (Linnaeus) Lamarck and I. aquatica Forsskål), several ornamentals (Ipomoea), several medicinal plants (Erycibe, Ipomoea, Cuscuta, Merremia, Dichondra, Evolvulus), and numerous noxious weeds (Cuscuta, Calystegia, Convolvulus).
Fang Rhui-cheng & Huang Shu-hua in Wu Cheng-yih, ed. 1979. Convolvulaceae. Fl. Reipubl. Popularis Sin. 64(1): 1-153.
Pollen aperture type and surface ornamentation are important characters in the classification of Convolvulaceae at the generic level and above. The most critical feature of the pollen is whether the grain surface is spiny or not. This distinction separates the eight tribes recognized by Austin (Ann. Missouri Bot. Gard. 60: 306-412. 1973) into two rather cohesive groups. A low magnification (20 ) is adequate for discerning the presence or absence of minute spines on the surface.
For the successful identification of Convolvulaceae, both flowering and fruiting material should be collected. The first key to genera requires adequate fertile material with both flowers and fruit, and requires use of a pollen character. The second key may be used as an aid to identification where material is lacking flowers or fruit, but in some instances it is still partially dependent upon having both flowers and fruit.
(Authors: Fang Rhui-cheng; George Staples)