Monday, 9 January 2012

Still not a tamarind

The plants keep fruiting.

31 December 2011

When I looked through the rainforest fruits book and found the illustration of the northern tamarind (Diploglottis diphyllostegia, Sapindaceae) (not actually a tamarind) I was sure I’d got my ID.

But it wasn’t quite right. The fruit matched the picture, but the leaves did not. Diploglottis diphyllostegia has compound leaves with 14 to 22 pairs of veins. The leaves on this plant are simple with rather fewer veins

I eventually found it — Dichapetalum papuanum (Dichapetalaceae) — a shrubby vine of FNQ and New Guinea. Dichapetalaceae is a pantropical family of 124 species in four genera. Dichapetalum is the only genus of the family in Australia. Two species occur in Far North Queensland. (See map below.)

Some species of Dichapetalum are known to produce the metabolic poison sodium fluoroacteate to deter herbivores. At least one (D. gelenoides of the Philippines) is a nickel hyperaccumulator. It looks as though these plants have declared all-out war on their predators. (I'll go out periodically to inspect the levels of herbivory to see who's winning. I'm predicting a stalemate.)

Herbarium records for the two Australian species of Dichapetalum: D. timorense (green) and D. papuanum (red). Both species also occur in New Guinea and Malesia.

Specimen data reproduced from Australia's Virtual Herbarium
with permission of the Council of Heads of Australasian Herbaria Inc.


laurak@forestwalkart said...

from the first picture...i thought they looked like kumquats...but then i see they're like siamese twins...or triplets!

they look yummy...deadly yummy.

hopefully the critters have them on their list of NO EATS!
(uh, you can always use them as a threat to the 'possum roofers! "here little possum...want some candy?!)

HEY i'm just kidding! anyone reading this, don't get all bent out of shape!! viva la 'possums!!

Snail said...

I had a look at the leaves this afternoon to see how well they deterred herbivores. Judging by the number of perforations and nibbled edges on the leaves, I'd say not very well at all!