Ipomoea nil

Nomenclature

Accepted name/Authority/Place of publication:

Ipomoea nil (L.) Roth, Catal. Bot. 1: 36. 1797.

Synonyms:

Convolvulus nil L., Sp. Pl. ed. 2. 1: 219. 1762

C. hederaceus L.

I. nil (L.) Roth var. setosa (Blume) Boerlage

I. scabra Forssk.

I. setosa Blume

I. trichocalyx Steud.

I. vaniotiana H. Lév.

Pharbitis nil (L.) Choisy

Misapplied name: Ipomoea hederacea authors not Jacq.: e.g., Gagnep. & Courchet in Lecomte, Fl. Indo-Chine 4: 241. 1915.

Description

Habit:

Herbs annual, twining, with retrorsely hirsute axial parts. Stems 2–5 m.

Leaves:

Petiole 2–15 cm; leaf blade broadly ovate or nearly circular, 4–15 × 4.5–14 cm, hirtellous, base cordate, margin entire or ± 3-lobed (rarely 5-lobed), apex acuminate.

Inflorescences:

Inflorescences axillary, 1- to few flowered; peduncle 1.5–18.5 cm; bracts linear or filiform, 5–8 mm, spreading hirtellous. Pedicel 2–7 mm.

Flowers:

Sepals lanceolate, ± equal, 1–2.5 cm, abaxial surface spreading hirsute, subglabrous apically, with a linear acumen, hairs swollen-based. Corolla pale to bright blue with whitish tube, fading to pinkish in age, funnelform, 5–6(–8) cm, glabrous. Stamens included, unequal. Pistil included; ovary glabrous, 3-loculed; stigma 3-lobed.

Fruits:

Capsule straw-colored, ovoid to ± globose, 8–10 mm in diam., glabrous.

Seeds:

Seeds black, ovoid-trigonous, 5–6 mm, gray puberulent.

Author:

Fang R.C. & G. Staples

References:

Fang R.C., G. Staples, et al. 1995. Convolvulaceae in P. Raven & C.Y. Wu (eds.) Flora of China 16: 271–325.

Cytology

Chromosome number:

Author:

Fang R.C. & G. Staples

References:

Fang R.C., G. Staples, et al. 1995. Convolvulaceae in P. Raven & C.Y. Wu (eds.) Flora of China 16: 271–325.

Biogeography, Ecology and Natural History

Distribution Map:

Distribution:

Native of tropical America, now nearly circumtropical as a naturalized weed and cultivated ornamental; in Kashmir, Pakistan, Nepal, India, Sri Lanka, Myanmar, Thailand, China, New Guinea, Australia.

Ecology:

China: Thickets on mountain
slopes, waysides, fields, hedges; 0–1600 m. Cultivated or escaped.

Thailand: Open,
mixed deciduous forest, scrub jungle, fire-damaged, degraded hardwood forest
with much bamboo, as well as vacant lots, gardens, rubbish dumps, roadside, on
diverse soil types; altitude: 50–700 m.

Phenology:

Flowering: January, June, August–December; fruiting: January, June, August–December.

Author:

Fang R.C. & G. Staples

References:

Fang R.C., G. Staples, et al. 1995. Convolvulaceae in P. Raven & C.Y. Wu (eds.) Flora of China 16: 271–325.

Staples, G. 2010. Convolvulaceae. Fl. Thailand 10(3): 330–468.

Other information

Common names and uses:

qian niu (Chinese). The seeds have a number of local medicinal uses. Wan tam khoei, wan phak bung, ji chaw (Thai).

General comments:

Ipomoea nil is a typical short-day plant, flowering when daylength decreases and nights are at their longest (October through December) in the northern hemisphere. The Japanese have developed an extraordinary array of cultivars by careful selection from the wild plants.