作者

STAPLES, George William and YANG, Sheng-Zehn

型態特徵

Herbs or shrubs, stems usually twining or scandent, less often prostrate or erect, sap often milky. Leaves alternate, simple, entire, dissected, or compound (scales in Cuscuta). Flowers solitary, axillary or in cymes, racemes, panicles, umbels, or capitula, hermaphroditic, actinomorphic, usually 5-merous, often showy. Sepals free, often persistent, sometimes accrescent in fruit. Corolla sympetalous, funnelform, campanulate, salverform, or urceolate; limb nearly entire 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 ring-like or cupular. Ovary superior, mostly 2-carpellate, 1- or 2-loculed, rarely 3- or 4-loculed; ovules basal, erect; style(s) 1 or 2, terminal (gynobasic in Dichondra) or very short or absent; stigma entire or lobed, rarely peltate. Fruit a capsule, dehiscing by valves, circumscissile, or irregularly shattering, less often a berry or nut-like. Seeds usually trigonous, smooth or pubescent.

Pollen aperture type and surface ornamentation are important characters in classification of Convolvulaceae at generic level and above. The most critical feature of the pollen is whether the grain surface is spiny or not. A 20 × hand lens or the low power of a dissecting microscope is adequate for discerning the presence or absence of minute spines on the surface. The number and arrangement of apertures is of secondary importance.

For successful identification of Convolvulaceae, both flowers and fruits are necessary. The following key to genera assumes that adequate fertile material with both flowers and fruit is available; sterile collections are hopeless unless the user of the key is well acquainted with the taxa in their fertile condition. Furthermore, the key requires use of a pollen character at a single point in order to proceed, although pollen characters are mentioned elsewhere as confirmatory evidence.

屬

With 58 genera and an estimated 2,000 species, Convolvulaceae are widely distributed in tropical, subtropical, and temperate regions. There are 14 genera and at least 44 species in Taiwan. Several additional taxa that are widespread weeds will likely be found in Taiwan in the future.

參考文獻