Ipomoea L.

Scientific Description

Common name. Morning Glories. Family Convolvulaceae.

Habit and leaf form. Herbs, or herbaceous climbers, or shrubs, or lianas; evergreen, or deciduous; laticiferous, or non-laticiferous and without coloured juice. Autotrophic. Herbs annual, or perennial; plants with neither basal nor terminal concentrations of leaves. Stem internodes solid, or hollow. Trailing or climbing, or self supporting; stem twiners. Twining anticlockwise. Hydrophytic, helophytic, mesophytic, and xerophytic; free floating, or rooted. Leaves alternate; spiral; petiolate to subsessile; non-sheathing; simple, or compound. Leaf blades dissected, or entire (entire to deeply lobed); when dissected, pinnatifid, or palmately lobed; pinnately veined, or palmately veined; cross-venulate; cordate, or hastate, or sagittate. Leaves without stipules (sometimes with pseudo-stipules); without a persistent basal meristem. Leaf anatomy. Hairs present (hairs simple or bifurcate), or absent. Stem anatomy. Nodes unilacunar. Secondary thickening anomalous, or developing from a conventional cambial ring; via concentric cambia, or from a single cambial ring.

Reproductive type, pollination. Fertile flowers hermaphrodite. Unisexual flowers absent. Plants hermaphrodite.

Inflorescence and flower features. Flowers solitary, or aggregated in ‘inflorescences’; when solitary, axillary. Inflorescence few-flowered to many-flowered. Flowers in cymes, or in heads (rarely). The terminal inflorescence unit cymose. Inflorescences axillary; with involucral bracts (when inflorescence capitate), or without involucral bracts (usually). Flowers bracteate; bi- bracteolate; small to large; regular to somewhat irregular. The floral asymmetry (when noticeable) involving the perianth (K only). Flowers 5 merous; cyclic; tetracyclic. Free hypanthium absent. Hypogynous disk present, or absent (rarely); annular. Perianth with distinct calyx and corolla; 10; 2 -whorled; isomerous. Calyx 5; 1 -whorled; polysepalous; hairy, or glabrous; imbricate; regular, or unequal but not bilabiate; persistent; accrescent, or non-accrescent; with the median member posterior. Corolla 5; 1 -whorled; gamopetalous; entire, or lobed. Corolla lobes markedly shorter than the tube. Corolla plicate; funnel-shaped (or salverform); regular; hairy abaxially (on mid-petaline bands), or glabrous abaxially; pink, or purple, or red, or blue, or white, or yellow. Androecium 5. Androecial members adnate (to the corolla); more or less all equal, or markedly unequal (usually); free of one another; 1 -whorled. Androecium exclusively of fertile stamens. Stamens 5. Staminal insertion near the base of the corolla tube. Stamens remaining included (usually), or becoming exserted; oppositisepalous. Filaments filiform, often dilated at the base. Anthers straight (when dehisced); dehiscing via longitudinal slits; introrse; tetrasporangiate. Pollen grains spinulose. Gynoecium 2(–5) carpelled. The pistil 2(–5) celled. Gynoecium syncarpous; eu-syncarpous; superior. Ovary plurilocular; 2(–5) locular. Gynoecium median. Styles 1; simple (filiform); apical; not becoming exserted (usually), or becoming exserted. Stigmas 1; 1 - lobed (then undulate), or 2(–3) - lobed; dry type; papillate (the papillae villiform); Group II type. Placentation basal. Ovules 2 per locule; ascending; apotropous; non-arillate; anatropous.

Fruit and seed features. Fruit non-fleshy; dehiscent, or indehiscent (rarely); a capsule, or capsular-indehiscent (rarely). Capsules loculicidal (from the summit via 4–6 valves), or splitting irregularly (rarely). Fruit 2–4 locular; 4–6 seeded (or fewer by abortion). Seeds trigonous; endospermic. Endosperm oily. Seeds conspicuously hairy, or not conspicuously hairy. Cotyledons 2. Embryo chlorophyllous; straight, or curved. Seedling. Germination phanerocotylar.

Physiology, biochemistry. Aluminium accumulation not found. Photosynthetic pathway: C₃.

Geography, cytology, number of species. Native of Australia. Not endemic to Australia. Australian states and territories: Western Australia, South Australia, Northern Territory, Queensland, New South Wales, and Victoria. Northern Botanical Province, Eremaean Botanical Province, and South-West Botanical Province.

Additional characters Pollen grains foraminate (pantoporate). Stigmas the stigmatic area globose (capitate or biglobular).

Etymology. From the Greek ips, ipos (a type of worm) and "resembling"; ips was formerly thought to mean Convolvulus, to which this genus is closely allied.