Macrosolen trigonus (Wight & Arn.) Tiegh. in Bull. Soc. Bot. France 42: 442. 1895, in obs. Loranthus trigonus Wight & Arn., Prodr. Fl. Ind. Orient. 1: 386. 1834; Hook.f., Fl. Brit. India 5: 219. 1886. Dendrophthoe trigona (Wight & Arn.) Danser ex Santapau in Rec. Bot. Surv. India 16: 263. 1953.

Young internodes sharply trigonous or margined on three sides, thereby becoming triquetrous, older ones terete, meristematically knotty at nodes; branching lateral. Leaves opposite, subopposite or whorled, broadly elliptic-ovate or suborbicular, cuneate or rounded and decurrent at base, entire or undulate along margins, obtuse or rounded at apex, 12 - 17 x 6 - 10 cm, crustaceous, glabrous; lateral nerves 4 or 5 pairs; petioles 9 - 15 mm long. Inflorescences centrifugal pseudoracemes, usually ramiflorous; peduncles 4 - 6-whorled at nodes, each 4 - 6- flowered, 12 - 15 mm long; flower buds spathulate, slightly gibbous at base, terete above with or without angular shoulders at middle, 1.2 - 1.5 cm long. Flowers 5-merous, 1.8 - 2.5 cm long; pedicels 2 - 3 mm long; bracts united with bracteoles, broadly ovate or suborbicular, 2 - 2.5 x 2.5 - 3 mm. Calyculus-tube entire or undulate, 0.8 - 1 mm long. Petals united; tube gibbous at base, usually splitting up to middle, 8 - 10 mm long; lobes 5, linear-elliptic, reflexed and coiled, 7 - 9.5 mm long. Stamens 5; filaments coherent to petals at base, free above, 4 - 5 mm long; anthers oblong, 2 - 3 mm long, with 1.5 - 2 mm long sterile emarginate apex. Ovary ellipsoid, 1.8 - 2 mm long; style up to 1 cm long; stigma capitate. Fruits usually ellipsoid or obovoid with persistent undulate-margined calyculus tube, smooth, 8 - 15 x 4 - 5 mm.

Fl. & Fr. Oct. - June.

Distrib. India: Western Peninsula in evergreen forests at 800 m and above, often found on Ficus spp. Maharashtra, Karnataka, Kerala and Tamil Nadu.

Endemic.

Notes. While all other species of this genus parasitise on a variety of hosts belonging to different genera and families, this particular species are known to parasitise only on species of Ficus.

Mesophyll of the leaves contain sclereids; fibres short, curved, angular with spicular projections.

Pollen triangular, aeriolate; P - 17 (20) 28 µm; E - 33 (41.5) 46 µm; P/E - 0.51 µm; ex. 1.5 µm; col. 0.5 µm.

Chromosome number: n = 9 (Sanjappa, Taxon 28: 393. 1979).