Stem or trunk shrubby, upright, climbing to a considerable height; bark of the old wood pale brown, of the young wood green and smooth; leaves generally growing four together, sometimes only two, and those opposite, sessile, smooth and glossy above, paler green beneath, the midrib on the underside evidently villous, veiny, veins as in _Plumeria_, terminating before they reach the margin, chewed discovering little taste; flowers very large, produced even on young plants, of a fine yellow colour, and somewhat spicy smell, not terminal, but growing from the sides of the branches, sometimes singly, more frequently three or four together, standing on short footstalks; calyx composed of five leaves, lanceolate, smooth, unequal, short compared with the flower; corolla mono-petalous, funnel-shaped, tube nearly cylindrical, limb dilated below and bellying out, on the inside striped with orange-coloured veins, above divided into five segments, which roll over each other before they open, when Open broad, somewhat truncated, one side rounded, the other terminating in a short point; at the base Of the divisions the yellow colour on the inside of the flower becomes nearly white, forming so many spots; the mouth of the tube is perfectly closed with villi converging to a point, and which serve as a covering or species of thatch to five long, pointed, rigid, arrow-shaped antheræ beneath them, which sit on the top of so many ridges, projecting from the inside of the tube, and which just beneath the antheræ are villous; germen nearly round, with a slight ridge on each side of it, surrounded at its base by a greenish glandular substance; style filiform, the length of the tube of the corolla, enlarging as it comes near to the stigma; stigma divisible into three distinct parts, the lowermost of a yellowish hue, in the form of a rim turning downwards, the middle of a dark green colour, secreting honey in considerable quantity; the summit, which perhaps is the true stigma, a short conical point, rising from the centre of the middle part, bifid at top with a furrow running down each side of it; seed-vessels according to the figure in AUBLET, are very large and prickly. Of this genus, which has a considerable affinity with that of _Vinca_ and _Plumeria_, only one species is described in LINNÆUS's works, and this is usually increased by cuttings. [339] ARUM TRILOBATUM. THREE-LOBED ARUM. _Class and Order._ GYNANDRIA POLYANDRIA. _Generic Character._ _Spatha_ monophylla cucullata. _Spadix_ supra nudus, inferne femineus, medio stamineus. _Specific Character and Synonyms._ ARUM _trilobatum_ acaule, foliis sagittato trilobis, flore sessili. _Linn. Syst. Veget. ed. 14. Murr. p. 828. Ait. Kew. V. 3. p. 316. Mill. Icon. t. 52. f. 2._ ARISARUM amboynicum. _Rumph. Amb. 5. p. 320. t. 110. f. 2._ [Illustration: _N^o. 339_]