Cynanchum carnosum

mangrove vine


Cynanchum carnosum

(R.Br.) Schltr. 1904

pronounced: kai-NAN-chum car-NO-sum

(Apocynaceae — the oleander family)

synonym — Ischnostemma carnosum

(R.Br.) Merr. & Rolfe 1908

pronounced: isk-noh-STEM-uh car-NO-sum

common names: mangrove vine, mangrove creeper

native 4Cynanchum is from the Greek κυνος (kynos), of a dog, and αγχειν (anchein), to strangle: several species of the genus are known as ‘Dog-strangling vine’, due to their toxicity; in the synonym, Ischnostemma is from ισχνος (ischnos), lean, meagre, and στεμμα (stemma), a wreath or garland; carnosum is from the Latin carnosus, fleshy.

Mangrove vine is found right across the top end, and southwards along the eastern coast to north-eastern NSW. The altitudinal range is very small, being more-or-less confined to the littoral zone just behind the mangroves. It is also found in New Guinea and parts of Malesia. The young plant pictured is on the creek bank in Picnic Bay, near the boat-trailer park, not actually growing on the mangroves (although there are some nearby), but scrambling over whatever it can find.

This is a slender vine with much-branched twining stems, glabrous or almost so, and a stem diameter not exceeding 2 cm. The petioles produce a clear exudate; the leaf blades are leathery, oblong-oblanceolate to obovate or elliptic, occasionally lanceolate or linear, up to about 6.5 by 3.5 cm in size, with petioles about 8–14 mm long; colleters are absent.

The flowers are pale green or yellowish green, 15 – 16 mm in diameter; the calyx lobes are about 2 mm long; the corolla lobes are 6 – 7 mm long. There is a corona of 5 conspicuous, whitish, erect distinct segments, the tips often recurved, longer than the column. The anthers are red.

The fruits are soft, not woody, 7.5 – 9 by 1 – 1.2 cm in size, more-or-less semi-orbicular in transverse section; the seeds are about 6 by 4 mm, with plumes of hair about 25 mm long.

This plant is the sole laval food plant of the Swamp Tiger butterfly (Danaus affinis). A rather sad-looking Swamp Tiger is pictured resting on the plant. It is also a nectar food plant for the Blue Tiger (Tirumala hamata) and the Lesser Wanderer (Danaus chrysippus).

There is a deal of revision currently taking place of the taxonomy of this genus. The 400 or so species at present placed there are polyphyletic, and species are being removed to other genera including Orthosia, Pentarrhinum and Vincetoxicum, with a group of mostly Old World species remaining in Cynanchum.


Photographs taken in Picnic Bay 2011
Page last updated 7th December 2018