40 
No. 85. 
Acacia decurrens, Willd. 
AND ITS VARIETIES. 
(Family LEGUMINOSyE : MIMOSA.) 
The Acacia Decurrens Group of Wattles. 
Black, Green, and Silver Wattles. 
The well-known feathery-leaved wattle, familiar to most people in the eastern and 
southern States—by whom it is chiefly known by one of two names, viz., Black or 
Green Wattle—was first botanically described by the botanist Willdenow, who 
defined two species, Acacia decurrens and Acacia mollissima. 
In the “Flora Australiensis,” Bentliam took Willdenow’s decurrens as the 
typical species, reducing the other species to the rank of a variety under the name 
of mollis; in other words, Acacia mollissima , Willd., is Acacia decurrens , Willd., var. 
mollis , Bentli. Bentliam also called a certain form variety normalis, a third one 
pauciglandulosa, and a fourth (doubtfully) Leichhardtii. 
In Mueller’s “Dichotomous Key to Victorian Plants,” he looked upon 
decurrens and mollissima as distinct species. 
I go further than Bentham, and reduce A. dealbata, Link, to a variety of 
decurrens. I will produce evidence for this step presently. 
These four varieties appear at first sight to he more or less well defined; hut, 
after examination of some hundreds of specimens, I have formed the opinion that 
they all pass into one another, and the mollis variety (in my view) has no more 
claim to specific rank than has pauciglandulosa. 
In stating this I am hut endorsing Bentliam’s words :— 
The following forms appear at first sight very distinct, but pass into each other by many gradations. 
Following are the points, stated briefly, on which I base my opinion :— 
1st. The pinnules of all vary more or less in each variety in length, breadth, 
and insertion. 
2nd. A decurrence of leaf-stalks is common to all. 
3rd. Nothing is constant in times of flowering. 
4th. The indumentum is variable. 
5th. Seed : the microscope fails to detect any marked difference. 
6th. The number of glands vary in each variety in the same tree. 
