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The families of flowering plants

L. Watson and M.J. Dallwitz

Convolvulaceae Juss.

Including Dichondraceae Dum., Erycibeae (Erycibaceae) Endl., Poranaceae J.G. Agardh; excluding Cuscutaceae, Humbertiaceae.

Habit and leaf form. Herbs (mostly, climbing or trailing), or shrubs, or lianas, or trees (a few); laticiferous (usually), or non-laticiferous, without coloured juice. Plants succulent, or non-succulent. Without conspicuous aggregations of leaves. Trailing or climbing (nearly always), or self supporting; stem twiners (characteristically), or scrambling; Convolvulus, Ipomoea, Rivea twining anticlockwise. Helophytic, mesophytic, and xerophytic. Leaves alternate; spiral; ‘herbaceous’, or fleshy; petiolate (mostly), or subsessile, or sessile; non-sheathing; simple. Lamina dissected, or entire (entire or lobed); when dissected, pinnatifid, or palmatifid; pinnately veined, or palmately veined; cross-venulate; cordate, or hastate, or sagittate. Leaves exstipulate; leaf development not ‘graminaceous’.

General anatomy. Plants with laticifers (usually, these articulated and non-anastomosing), or without laticifers.

Leaf anatomy. The leaf lamina dorsiventral, or bifacial (commonly isobilateral), or centric (rarely, e.g. some Wilsonia spp.). Stomata mainly confined to one surface, or on both surfaces; paracytic (mostly), or anomocytic, or anomocytic and paracytic. Hairs present (commonly represented by 2-armed trichomes, Y- or T-shaped forms, and forms with one to several short stalk cells and a long terminal one: see illustration); eglandular and glandular. Adaxial hypodermis present (but incomplete), or absent (usually). The mesophyll with sclerenchymatous idioblasts, or without sclerenchymatous idioblasts; containing crystals. The crystals druses and solitary-prismatic. Minor leaf veins without phloem transfer cells (Convolvulus, Ipomaea).

Axial (stem, wood) anatomy. Pith with diaphragms, or without diaphragms. Cork cambium present; initially superficial. Nodes unilacunar. Primary vascular tissues at least usually in a cylinder, without separate bundles; bicollateral. Internal phloem present. Cortical bundles absent. Medullary bundles present (by development of xylem associated with the intraxylary phloem, resulting in inversely orientated bundles), or absent. Secondary thickening anomalous (often), or developing from a conventional cambial ring. The anomalous secondary thickening often asymmetric, via concentric cambia (commonly), or from a single cambial ring. Primary medullary rays narrow.

The wood diffuse porous. The vessels small to large. The vessel end-walls simple. The axial xylem with tracheids; with fibre tracheids (in addition to tracheids), or without fibre tracheids. ‘Included’ phloem present, or absent.

Reproductive type, pollination. Plants hermaphrodite (usually), or dioecious (Hildebrandtia).

Inflorescence, floral, fruit and seed morphology. Flowers solitary, or aggregated in ‘inflorescences’; when aggregated, in cymes. The ultimate inflorescence units cymose. Inflorescences nearly always simple or compound dichasia, or a cincinnus; with involucral bracts (often), or without involucral bracts. Flowers bracteate; bracteolate (usually?), or ebracteolate (e.g. Wilsonia); medium-sized, or large; regular to somewhat irregular. The floral irregularity (when noticeable) involving the perianth (K only). Flowers usually 5 merous; cyclic; tetracyclic. Free hypanthium absent. Hypogynous disk present; annular.

Perianth with distinct calyx and corolla; 10; 2 whorled; isomerous. Calyx 5; 1 whorled; polysepalous, or gamosepalous (rarely); persistent; imbricate; with the median member posterior. Corolla 5; 1 whorled; gamopetalous; valvate and plicate, or contorted and plicate; tubular (mostly, more or less), or campanulate, or urceolate; nearly always regular; not fleshy.

Androecium 5. Androecial members adnate (to the base of the corolla); all equal, or markedly unequal (often); free of one another; 1 whorled. Androecium exclusively of fertile stamens. Stamens 5; inserted near the base of the corolla tube (mostly), or midway down the corolla tube; oppositisepalous. Anthers dehiscing via longitudinal slits; introrse; tetrasporangiate. Microsporogenesis simultaneous. The initial microspore tetrads tetrahedral, or decussate. Anther wall initially with one middle layer; of the ‘dicot’ type. Tapetum glandular. Pollen grains aperturate; 3 aperturate, or 4–20 aperturate (to polyforaminate); colpate (including rupate), or porate, or colporate (?), or foraminate, or rugate; 2-celled (7 genera), or 2-celled and 3-celled (with both conditions in Ipomoea).

Gynoecium 2(–5) carpelled. The pistil 1 celled, or 2(–5) celled. Gynoecium syncarpous; synovarious to eu-syncarpous, or synstylous (i.e. the carpels sometimes joined only by the common style); superior. Carpel when the ovaries are free, (1–)2 ovuled. Placentation basal. Ovary (1–)2(–5) locular (sometimes bilocular above with the septum incomplete below, and occasionally the ‘locules’ free of oneanother). Gynoecium median. Styles 1–5; free to partially joined; apical, or ‘gynobasic’. Stigmas dry type; papillate; Group II type. Placentation basal. Ovules (1–)2 per locule; ascending; apotropous; with ventral raphe; non-arillate; anatropous; bitegmic; tenuinucellate, or crassinucellate. Embryo-sac development Polygonum-type. Polar nuclei fusing only after one has been fertilized, or fusing simultaneously with the male gamete (?). Antipodal cells formed; 3; not proliferating; usually ephemeral. Synergids usually slender and elongated, rarely small and ephemeral. Endosperm formation nuclear. Embryogeny caryophyllad.

Fruit fleshy, or non-fleshy; when synstylous, an aggregate, or not an aggregate. The fruiting carpels coalescing into a secondary syncarp to not coalescing. The fruiting carpel when synstylous, dehiscent, or indehiscent; nucular, or baccate. Fruit dehiscent, or indehiscent; a capsule, or a berry, or a nut. Capsules loculicidal, or circumscissile, or splitting irregularly. Seeds endospermic. Endosperm oily. Seeds conspicuously hairy, or not conspicuously hairy. Cotyledons 2 (plicate, often bifid); folded, or crumpled. Embryo chlorophyllous (5/11); straight, or curved.

Seedling. Germination phanerocotylar.

Physiology, phytochemistry. C3. C3 physiology recorded directly in Convolvulus, Cressa, Dichondra, Evolvulus, Ipomea, Jacquemontia, Merremia, Seddera. Anatomy non-C4 type (Astripomoea, Convolvulus, Cressa, Falkia, Ipomoea, Lepistemonopsis, Merremia, Seddera). Cyanogenic, or not cyanogenic. Cynogenic constituents phenylalanine-derived (?), or of Hegnauer’s ‘Group C’ (?). Alkaloids present (commonly), or absent. Arbutin absent. Iridoids not detected. Saponins/sapogenins absent (usually), or present. Proanthocyanidins absent. Flavonols present, or absent (Ipomoea); kaempferol and quercetin. Ellagic acid absent (4 species, 3 genera). Aluminium accumulation not found. Sieve-tube plastids S-type.

Geography, cytology. Temperate to tropical. Cosmopolitan. X = 7–15(+).

Taxonomy. Subclass Dicotyledonae; Tenuinucelli. Dahlgren’s Superorder Solaniflorae; Solanales. Cronquist’s Subclass Asteridae; Solanales. APG III core angiosperms; core eudicot; Superorder Asteranae; lamiid. APG IV Order Solanales.

Species 1650. Genera about 55; Aniseia, Argyreia, Astripomoea, Blinkworthia, Bonamia, Breweria, Calycobolus, Calystegia, Cardiochlamys, Cladistigma, Convolvulus, Cordisepalum, Cressa, Decalobanthus, Dichondra, Dicranostyles, Dinetus, Dipteropeltis, Erycibe, Evolvulus, Falckia, Hewittia, Hildebrandtia, Hyalocystis, Ipomoea, Iseia, Itzaea, Jacquemontia, Lepistemon, Lepistemonopsis, Lysiostyles, Maripa, Merremia, Metaporana, Nephrophyllum, Neuropeltis, Neuropeltopsis, Odonellia, Operculina, Paralepistemon, Pentacrostigma, Pharbitis, Polymeria, Porana, Poranopsis, Rapona, Rivea, Sabaudiella, Seddera, Poranopsis, Rapona, Rivea, Sabaudiella, Seddera, Stictocardia, Stylisma, Tetralocularia, Tridynamia, Turbina, Wilsonia, Xenostegia.

General remarks. See Austin 1973. Intkey comparisons of the descriptions compiled for the present package offer enough differences in character correlations to defend retaining Cuscutaceae and Humbertiaceae (q.v.) as separate families.

Illustrations. • Le Maout and Decaisne: Convolvulus, Calystegia. • Le Maout and Decaisne: Dichondra. • Ipomoea batatoides: Lindley. • Jacquemontia capitata: Thonner. • Batatas (= Ipomoea) betacea Lindl.: Bot. Reg. xxvi, 56 (1840). • Calystegia tuguriorum: Hooker, Fl. Novae-Zelandiae (1853). • Cardiochlamys madagascariensis: Hook. Ic. Pl. 15 (1883). • British Convolvulus, Calystegia (B. Ent. compilation, 1824–35. • Convolvulus arvensis: Eng. Bot. 923 (1866). • Convolvulus farinosus: Bot. Reg. 1323, 1830. • Convolvulus scoparius: Bot. Reg. 43, 1841. • Ipomoea aitonii: Bot. Reg. 1794, 1836. • Ipomoea batatoides: Bot. Reg. 36, 1841. • Ipomoea cymosa: Bot. Reg. 29 (24), 1843. • Lepistemon owariense, as L. africanum: Hook. Ic. Pl. 13 (1877–79). • Pharbitis x hirsutula: as P. diversifolia, Bot. Reg. 1988, 1837. • Pharbitis ostrina: Bot. Reg. 51, 1842. • Porana volubilis: Wight’s Figs. of Indian Plants 2 (1843). • Quamoclit lobata: as Mina lobata, Bot. Reg. 24, 1842. • Leaf hairs: Bonamea, Cardiochlamys, Dichondra, Evolvulus Ipomoea, Jacquemontia (Solereder, 1908).

We advise against extracting comparative information from the descriptions. This is much more easily achieved using the DELTA data files or the interactive key, which allows access to the character list, illustrations, full and partial descriptions, diagnostic descriptions, differences and similarities between taxa, lists of taxa exhibiting or lacking specified attributes, distributions of character states within any set of taxa, geographical distribution, genera included in each family, and classifications (Dahlgren; Dahlgren, Clifford, and Yeo; Cronquist; APG). See also Guidelines for using data taken from Web publications.

Cite this publication as: ‘Watson, L., and Dallwitz, M.J. 1992 onwards. The families of flowering plants: descriptions, illustrations, identification, and information retrieval. Version: 15th April 2018.’.