Convolvulaceae

旋花科

APG 4

Convolvulaceae 旋花科

特徵描述

屬列表

標本列表

特徵描述

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

STAPLES, George William and YANG, Sheng-Zehn, Flora of Taiwan, second edition 4: 341. 1998. (Fl. Taiwan 2nd edit.)
Austin, D. F., D. A. Powell & D. H. Nicolson., Brittonia 30(2): 195-198. 1978.
Chang, C. E., Flora of Taiwan 4: 347-389. 1978. (Fl. Taiwan)
Fang, R. C. & G. W. Staples., Flora of China Family 16: 271-325. 1995. (Fl. China)
Fang, R. C. & Huang S. H., Flora Reipublicae Popularis Sinicae 64(1): 11-53. 1979. (Fl. Reip. Pop. Sin.)
Ferguson, I. K., B. Verdcourt & M. M. Poole., Kew bulletin 31(4): 763-773. 1977. (Kew Bull.)
Lu, F. Y., Quarterly journal of Chinese forestry 6: 105-165. 1972. (Quart. J. Chin. For.)
Nicolson, D. H., C. R. Suresh, & K. S. Manilal, An interpretation of Van Rheedes Hortus Malabricus Regnum Veg. 119: 1-378. 1988.
Ooststroom, S. J. van, Flora Malesiana : Series I : Spermatophyta 4(4): 388-512. 1953. (Fl. Males. Ser. I)

Ipomoea 牽牛花屬

作者

STAPLES, George William and YANG, Sheng-Zehn

型態特徵

Herbs or shrubs, often twining, sometimes prostrate, erect, or floating. Leaves petiolate, entire, lobed, or divided. Inflorescences mostly axillary, cymose, 1-few to many Flowered, rarely paniculate; bracts various. Flowers small to large. Sepals persistent, equal to unequal, ± enlarged in Fruit. Corolla variously colored, rarely yellow, funnelform, campanulate, or salverform; limb 5-lobed to entire, midpetaline bands well-defined. Stamens included or exserted; filaments filiform, usually unequal, dilated and pubescent basally; anthers ovate or linear, longitudinally dehiscent, not twisted; pollen globular, pantoporate, finely spiny. Disc ring-like. Ovary 2-, 3-, or 4-loculed, 4- or 6-ovuled; style 1, filiform, included or exserted; stigma capitate, or 2- or 3-globulose. Capsule globose or ovoid, 4- or 6-valved. Seeds 4(–6) or fewer, glabrous or pubescent.

Ipomoea marginata (Desr.) Verdc. (Kew Bull. 42: 658. 1987, synonym I. sepiaria Koenig ex Roxb.; I. maxima sensu auct.) was reported from Taiwan in older literature (viz., Matsumura & Hayata, Enum. Pl. Ins. Formosa in J. Coll. Sci. Imp. Univ. Tokyo 22: 265. 1906) but recent accounts have not included the species. We traced a single collection made before 1895 (Formosa, Takow, side of rice field, A. Henry 1954 (E!, K!)) but have seen no recent collections. I. marginata can be confused with I. triloba when sterile of in fruit, but the salverform, 2.5–4 cm long corolla, white or purple with darker center, immediately separates the two. It has not been included in the present treatment. Collectors, however, are encouraged to look out for it.