Cayratia emarginata Trias-Blasi & J.Parn., 2011

Trias-Blasi, A., Parnell, J. A. N., Chayamarit, K. & Teerawatananon, A., 2011, Cayratia emarginata (Vitaceae), a new species from Thailand and Vietnam, Blumea 56 (1), pp. 16-17 : 16-17

Cayratia emarginata Trias-Blasi & J.Parn. , sp. nov. — Fig. 1

Species Cayratia trifolia ( L.) Domin affinis,ab affinibus differt petala farinosus pilis omnio destituta et folia apice cuspidatus. — Typus: A. F. G. Kerr 10924 (holo P; iso BK, BM, K, L), Sam Roi Yawt [= Sam Roi Yot], Prachuap Khiri Khan Province, South-Western Region, Thailand, 7 Nov. 1926 .

Herbaceous climber. Stem cylindrical, 1–3 mm diam, branched, hairy with soft villous hairs to 1 mm long, ridged; tendril 2 – 3-furcate, slender, wiry, leaf-opposed, cylindrical, peduncle straight, 1.5– 4 cm by 0.5–1 mm, then bifurcating and coiling for 2–7 cm, hairy as stem. Leaves 3-foliolate, alternate; petiole 1–3.5 by

1 Herbarium, Department of Botany , School of Natural Sciences, Trinity College Dublin, University of Dublin, Dublin 2, Ireland .

* Current address: Herbarium, Library, Art & Archives, Royal Botanic Gar- dens, Kew, Richmond, Surrey, TW9 3AE, United Kingdom; corresponding author e-mail: [e-mail].

2 Queen Sirikit Botanic Garden, P. O. Box 7, Mae Rim, Chiang Mai 50180, Thailand .

3 Thailand Natural History Museum,National Science Museum,Technopolis, Pathum Thani 12120, Thailand.

c. 1 mm, hairy as stem, central petiolule 0.5 –1.5 cm long, lateral petiolules 0.3 –0.7 mm long, hairy as stem; central leaflet blade oval to ovate, 3 –6 by 1.5– 3 cm, base truncate to subauriculate; lateral leaflet blades semi-cordate, 3– 5 by 2 – 2.5 cm, base oblique to cordate; margin deeply dentate with triangular teeth to 4 by 5 mm, apex cuspidate; adaxial and abaxial sides hairy with appressed hairs to 1 mm long, veins protruding, 1 main basal vein, 6 pairs of secondary veins. Inflorescence ramified, axillary, mostly dividing dichotomously, corymbose, 1–2 cm long; peduncle 3.5 –4 cm by c. 1 mm, hairy as stem, pedicel 1.5– 2 mm long, puberulent with hairs to 0.1 mm long. Buds globose to ovoid, 1.5 – 2 by 1–1.5 mm. Calyx cupuliform, entire, margin sinuate, c. 0.5 by 1.5 mm, hairy as pedicel. Petals 4, ovate, 2– 2.3 by 1–1.5 mm, apex cucullate, farinose, hairless. Stamens 4; filaments flattened, broadening at the base, c. 1.3 mm long; anthers elliptic, medifixed, c. 0.8 mm long. Ovary adnate to the disc; disc with 4 distinct lobes, cupulate, 0.5 –1 by c. 1.5 mm, glabrous. Style conical, c. 0.8 mm long; stigma inconspicuous. Fruit unavailable.

Distribution — Thailand and Vietnam. A disjunct distribution, not yet collected in Cambodia, Laos and E/SE Thailand.

Habitat & Ecology — Growing on limestone at ≤ 50 m. Flowering in July.

Specimens examined. THAILAND, Prachuap Khiri Khan, Sam Roi Yawt, 7 Nov. 1926, A. F. G . Kerr 10924 ( BK, BM, K, L, P); Trang, Subdistrict Lam- pura, Tham i-so, 8 Apr. 2007, A . Trias Blasi 35 ( BKF, TCD); Sa Kaeo, Khao Tangok. trail to the top, 24 Apr. 2007, A . Trias Blasi 52 ( BKF, TCD) .– VIETNAM, Cochinchine, mont Dinh, près de Ba Ria, Pierre 4353 ( P) .

Notes — Cayratia emarginata is morphologically closest to C. trifolia . However, they can be easily distinguished because C. emarginata has farinose hairless petals and a cuspidate leaf apex, while C. trifolia has slightly to densely puberulent petals and an acute leaf apex.

Generally in Thai Cayratia the habit type seems to be correlated with seed morphology. Thus, species with herbaceous habit have seeds with an adaxial side with 2 faces and lack a deep cavity and occluding membrane, while species with a woody habit have seeds with their adaxial side possessing a cavity occluded by a membrane. Although no C. emarginata seeds have been seen, it is likely that if this character correlation is maintained, this species has seeds with an adaxial side with 2 faces and no cavity.

The specimen collected in the Sa Kaeo province, had a sticky secretion on the stems. In addition, all of the specimens examined grow in limestone terrain.

We have used as a holotype the duplicate of the specimen held in P, because it contains flowers and is a good representative of the species. This specimen was previously identified as Cayratia mollissima . It can be easily differentiated from it because C. emarginata has a herbaceous habit and its leaves are generally much smaller (3–6 by 1.5 –3 cm), while C. mollissima has a woody habit and bigger leaves (7–20 by 2.5 –10 cm).

Figures

Fig. 1 Cayratia emarginata Trias-Blasi & J.Parn. a. Vegetative stem; b. flowering stem; c. flowers (all A.F.G. Kerr 10924 (P)). — Drawn by A. Teerawatananon.