Causonis trifolia

Trias-Blasi, Anna, Dee, R., Jimbo, Tiberius, Jackes, Betsy & Parmar, Gaurav, 2022, Taxonomic revision of Causonis (Vitaceae) in New Guinea, Edinburgh Journal of Botany 79 (1895), pp. 1-10 : 8-9

3. Causonis trifolia (L.) Mabb. & J.Wen in Mabberley, Pl.-Book, ed. 4, 1101 (2017).

Vitis trifolia L., Sp. Pl. 203 (1753); Cissus trifolia (L.) K.Schum. in Schumann & Hollrung,

Fl. Kais. Wilh. Land 71 (1889); Columella trifolia (L.) Merr., Philipp. J. Sci., C, 134

(1916); Cayratia trifolia ( L.) Domin , Biblioth. Bot. 89: 370 (1927). – Type: India, Madras, “Pearmedoor, about 16 or 17 miles from Fort St George”, 27/ 28 v 1969, Herb. Sloane 165 (Petiver): 84, Samuel Browne 67 ( BM-SL!, neotype, designated by Shetty & Singh, Taxon 37: 171 [1988]) .

Cissus carnosa Lam., Encycl. 1: 31 (1783); Vitis carnosa (Lam.) Wall. ex M.A.Lawson in Hooker 654 (1875); Cayratia carnosa (Lam.) Gagnep., Notul. Syst. 347 (1911). – Type: [illustration] India, “Tsjori-Valli” in Rheede tot Draakestein, Hort. Malab. 7: t. 9 (1688) (lectotype, designated by Mabberley in Dassanayake et al., Handb. Fl. Ceylon 9: 458 [1995]).

Cissus obtusifolia Lam., Encycl. 1: 31 (1783). – Lectotype (designated by Parmar et al., Taxon 70(6): 1214 [2021]): India., s.d., J.B. Lamarck s.n. (P [barcode P00295584 !]).

Cissus cinerea Lam., Tabl. Encycl. l: 332 (1791) ≡ Cayratia trifolia var. cinerea (Lam.) Quisumb., Philipp. J. Sci. 76: 47 (1944). – Lectotype (designated by Parmar et al., Taxon 70(6): 1214 [2021]): East Indies , s.d., J.B. Lamarck s.n. (P [barcode P00295579 !]).

Vitis psoraliifolia F.Muell., Fragm. 2(13): 75 (1860) ≡ Cissus psoraliifolia (F.Muell.) Planch.

in Candolle & Candolle, Monogr. Phan. 5: 567 (1887). – Type: not designated; original material: Australia. Northern Territory, on the riverbank of Victoria River , x 1855, F .

Mueller s.n. (GH n.v., K n.v., MEL [barcodes MEL 540157!, MEL 540158!]; vide Jackes in Austrobaileya 2(4): 368 (1987).

Herbaceous climber. Stem terete, 1–4 mm in diameter, very branched, hairy with pale bent hairs 0.2–1 mm long to glabrous, slightly ridged; tendril 4- or 5-furcate, slender, wiry, leaf opposed, cylindrical, with a non-coiling section followed by coiling section, 2.5–10(–20) cm long, sparsely hairy to glabrous, mature tendrils usually forming adhesive discs at the tips. Leaves compound, 3-foliolate, alternate; petiole 1–6 cm long, hairy as on stem, central petiolule 0.4–2.5 cm long, lateral petiolules 2–8 mm long, hairy as on stem; central leaflet blade oval, lanceolate to ovate, 2–11 × 1–7 cm, base cuneate to rounded; lateral leaflet blade 2.5–7 × 2–6 cm, sometimes with a lateral lobe, base oblique; margin dentate to sinuate, apex acute to acuminate; adaxial surface almost glabrous except for the presence of hairs (like those on the stem) on the midrib to densely hairy with appressed hairs, abaxial side moderately to densely hairy with hairs like these on the stem mostly concentrated on veins; veins protruding, 1 main basal vein, 4–8 pairs of secondary veins. Inflorescence a ramified, axillary, mostly dividing dichotomously, corymbose dichasium, 2–12 cm long; peduncle 1.5–8 cm long, hairy as on stem, pedicel 1–3 mm long, hairy with hairs to

0.1–0.2 mm long. Buds ovoid, 1.5–2 × 1–2 mm. Calyx cupuliform, entire, margin sinuate, 0.5–0.75 × 1.5–2 mm, hairy as in pedicel. Corolla petals 4, ovate, 2–2.25 × 1–1.5 mm, apex cucullate, sparsely to densely puberulent. Stamens 4; filaments flattened, broadening at the base, 0.75–1 mm long; anthers orbicular, medifixed, 0.4–0.75 mm long. Ovary adnate to the disc; disc with 4 distinct lobes, 0.5–1 × 1.5 mm, glabrous. Style conical, slender, 0.5–0.6 mm long; stigma inconspicuous. Fruit a berry, subglobose, 5–15 mm in diameter, glabrous, smooth, base attenuate. Seeds 2–4, triangular, 5–6 × 4.5–5 mm, ventral side keel-shaped, dorsal side convex with a linear chalazal knot, side ribbed; endosperm m-shaped in cross-section. See Figure 2B, C–E .

Distribution. Australia, Bangladesh, Brunei, Cambodia, China, India (including Andaman and Nicobar Islands), Indonesia (Borneo, Java, Lesser Sunda Islands, New Guinea, Sulawesi, Sumatra), Laos, Malaysia, Micronesia, Moluccas, Myanmar, Nepal, Palau, Pakistan, Papua New Guinea, Philippines, Singapore, Solomon Islands, Sri Lanka, Thailand, Vanuatu and Vietnam.

Distribution in New Guinea. Indonesia: Irian Jaya (see Figure 1 ).

Habitat and ecology. Forests on hillsides or by streams, on rocks; around 70–1300 m altitude.

Phenology. Flowering and fruiting throughout the year.

Proposed IUCN conservation category. Causonis trifolia is a widespread species across Asia with no apparent threats, and therefore it can be treated as Least Concern. In New Guinea, we have been able to confirm the identity of ony one specimen because it was the only one bearing fruits, but it is extremely likely that the species is widespread in the country. As such, the species is classified as Least Concern ( LC) .

Additional specimen examined. INDONESIA. Irian Jaya: Bomberai Peninsula, Tangguh survey area, S of Tanah Mera , 2°27.4′S, 133°7.4′E, 20 ii 2002, Takeuchi, Sambas & Maturbongs 15982 ( BO [BO-1486756], K, L [ L.3928844, L.3928845]) .

ORCID iDs

A. Trias-Blasi https://orcid.org/0000-0001-9745-3222

R. Dee https://orcid.org/0000-0002-0517-278X

T. Jimbo https://orcid.org/0000-0003-0651-5307

B. Jackes https://orcid.org/0000-0001-5645-9767

G. Parmar https://orcid.org/0000-0002-8876-5520

Figures

Figure 1. Map showing the distribution of Causonis australasica, C. maritima and C. trifolia in New Guinea.

Figure 2. Distinctive characters in New Guinea Causonis. A and B, Tendrils: A, Causonis maritima; B, C. trifolia (adapted from Jackes, 1987). C–H, Seeds: C–E, Causonis trifolia (C, cross-section; D, ventral view; E, dorsal view); F–H, Causonis maritima (F, cross-section; G, ventral view; H, dorsal view). Drawn by A. Trias-Blasi.