e-Flora of Thailand

Volume 10 > Part 3 > Year 2010 > Page 451 > Convolvulaceae > Operculina

1. Operculina petaloidea (Choisy) Ooststr.wfo-0001298124

Blumea 3: 369. 1939; Kerr, Fl. Siam. Enum. 3(2): 8. 1951; Songkhla & Khunwasi, Thai Forest Bull. (Bot.) 20: 68. 1993.— Ipomoea petaloidea Choisy in DC., Prodr. 9: 360. 1845; Gagnep. & Courchet in Lecomte, Fl. Indo-Chine 4: 257. 1915. Fig. 36.


Accepted Name : This is currently accepted.



Synonyms & Citations :

Ipomoea petaloidea var. pauciflora C.B.Clarke in Hook.f., Fl. Brit. Ind. 4: 212. 1883; Prain, J. Asiat. Soc. Bengal, Pt. 2, Nat. Hist. 63(2): 110. 1894.— Operculina petaloidea var. pauciflora (C.B.Clarke) Parmar, J. Econ. Taxon. Bot. 18(2): 251–252. 1994, syn. nov.


Description : Herbaceous twiner, glabrous or yellowish puberulent near nodes; stems terete, striate, or narrowly alate below nodes. Leaves ovate, broadly elliptic, to oblong-linear, 5.8–11.3 by 2.7–5.8 cm, pubescent when young, later glabrate, base rounded to truncate, apex obtuse or acute, mucronulate; lateral veins 7–9 per side; petiole 1.5–2.6 cm, ridged to narrowly winged. Inflorescence axillary or terminal on branches, cymose, 1–9-flowered; peduncles terete, 0.9–2 cm; bracts linear-lanceolate, 7–20 mm, deciduous; pedicels clavate, striate-angulate, 10-18 mm. Flower: sepals subequal, elliptic, convex, outer 2 narrower, 13–15 mm long, mucronulate, inner broader, 15 mm; corolla flaring funnelform, 3.5–4 cm, pale yellowish, midpetaline bands sericeous outside, inside glabrous; stamens subequal, included, filaments 14–18 mm, glandular below insertion, anthers spirally dehiscent; pistil included, 17–19 mm long, glabrous, ovary broadly ovoid. Capsule ca 15 mm diam., tan, cupped by accrescent calyx. Seeds 4, ovoid, 5–6 mm long, black.


Thailand : NORTHERN: Mae Hong Son, Chiang Mai, Chiang Rai, Lampang; SOUTH WESTERN: Kanchanaburi.


Distribution : India, Myanmar (type), Cambodia, Vietnam.


Ecology : Uncommon, in sunny areas in evergreen forests, along stream banks, roadsides, 180–1,200 m alt. Flowering: February–April, November.


Vernacular : Ban bai (บานบ่าย); khrue-chicho-khaeng (เครือจี้จ้อแข็ง)(Chiang Mai).


Notes: Several authors of Indian floras, beginning with C.B. Clarke (l.c.) have tried to distinguish infraspecific taxa based on leaf shapes. As shown by Songkhla & Khunwasi (l.c., Fig. 34, 35) the leaves vary considerably in shape and these can all be found on the same plant. It seems that cauline leaves tend to be broader and the leaves on lateral shoots may be the same shape, only smaller, or narrower and linear-oblong in shape. Recognizing varieties based on this sort of variation is pointless and the linear-leaved variety is subsumed as a synonym here.


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