Merremia dissecta

Alamo vine

 

Merremia dissecta

(Jacq.) Hallier f. 1893

pronounced: me-REE-mee-uh dy-SEK-tuh

(Convolvulaceae — the morning glory family)

 

common names: Alamo vine, Noyau vine

Merremia commemorates a German naturalist (with emphasis on ornithology), Blasius Merrem (1761–1824), who was a professor of mathematics and physics at Duisburg in the Rhineland-of-North-Westphalia, Germany. His Tentamen Systematis Naturalis Avium on bird classification is still highly regarded today. Dissectus is Latin for ‘cut in pieces’.

Alamo vine is a white perennial morning glory that opens round about noon and then closes before sunset. It is a native of tropical America, and is to be found all over Magnetic Island, mainly climbing on fences and in waste ground. It is a very efficient plant at reproducing itself, colonizing from rhizomes, runners and seed. It is a perennial, broad-leafed herbaceous climber with hairy, anti-clockwise twining stems, and can climb up to about 4 m high.

The leaves are alternate, spiral, simple, petiolate, with very hairy petioles 2 – 7 cm long. The leaf blade is usually 4 – 8 cm long and 6 – 12 cm wide, dissected, palmately lobed with 3–7 segments, each deeply 5–7 lobed.

The flowers are predominantly white with some red or purple, and somewhat irregular. There are 5 free sepals. The corolla is 3.5 – 4.5 cm long, with 5 petals joined into a funnel shape. There are also 5 stamens. The flowering period is generally February, April to July, and September.

The fruit is a dehiscent 5-valved capsule, globular, papery, smooth and non-fleshy, up to almost 2 cm long, and with a similar, usually slightly larger, width. It splits open to reveal a smaller seed container inside of a similar shape to the fruit itself, with a papery exterior. Inside this, separated by a stiffish wall, are two black seeds.

The plant is found in all Australian states except for Victoria and the southern parts of NSW, either growing wild or cultivated. In the dry season the plant is just a mass of brown, dead-looking vines entangled in the fences.

Together with other species in this genus, Alamo vines can be very invasive in waste ground and along road verges. In Picnic Bay, they grow especially profusely on the fences around the old school, and in the waste ground of the old service station site.

This is a host plant for the caterpillars of the Convolvulus Hawk Moth Agrius convolvuli.

                                                                                                    

An Essay on the Natural System of Birds

 

Photographs taken at Picnic Bay 2009
Page last updated 5th February 2019