26 Hardy, Distribution of Leaf Glands in Acacias. rv^i"^'xxix 



THE DISTRIBUTION OF LEAF GLANDS IN SOME 

 VICTORIAN ACACIAS. 



By a. D. Hardy, F.L.S., F.R.M.S. 

 (With Plate.) 

 {Read before the Field Naturalists' Club of Victoria, i^th May, 1912.) 

 The glands of the acacias have received, generally, little notice, 

 but a few botanists ' have drawn attention to them in describing 

 several species, and one '^ has referred frequently to this feature 

 in his systematic arrangement of the Australian species of the 

 genus as an auxiliary rather than as an essential character in 

 specific diagnosis. In one case, to be referred to later, the 

 gland has been given undue importance where associated with 

 an apparently supernumerary nerve connecting it with the 

 midrib. Notwithstanding the provincial aspect of the title 

 given to it, this paper includes reference to a number of extra- 

 Victorian species of interest, and for this I am indebted to 

 Professor Ewart, D.Sc, Government Botanist of Victoria, who 

 made the National Herbarium collection available for examina- 

 tion, and also to Mr. J . Cronin, Director of the Botanic Gardens, 

 Melbourne, by whose permission I am enabled to exhibit 

 several of the specimens. 



BiPiNNAT.E — Of the two easily recognizable divisions of the 

 genus — viz.. the bipinnatcc (or feather-leaved acacias) and the 

 phyllodinece (or " flat-leaved " species), we may first notice 

 the former. In referring to these I will avoid the use of the 

 term " common petiole," and regard the leaf as composed of 

 the petiole and its i)roduction, the rhachis, the latter liearing 

 the pinna;, which, in turn, support the leaflets. The com- 

 monest occurrence of the glands in the bipinnate s])ecies is as 

 a suite, of which one is to be found on the petiole, slightly 

 removed from and below the first pair of pinna;, and the re- 

 mainder distributed along the rhachis — one at or just below 

 the base of each pair. But, although the simple suite is 

 evidently the normal condition, there is only approximate 

 constancy, since the examination of any tree in any locality, 

 or even one small branch, will almost surely disclose leaves 

 with sui)erfluous glands, or ])erha])s with some missing, the 

 former case being more frequent. In this my exi)erience con- 

 firms Mr. Maiden's record ^ in connection with the varieties of 

 A. dccurrcns. To these, in this connection, may be added A. 

 BaUeyaiiu, A. spcciabilis, &c. Bentham ■■* remarks that "the 

 glands on the up])er edge of the phyllodia and in the common 

 ])etiole of the compound leal seldom afford even u specific 

 distinction." Of the exceptions, .1. dcairrens, var. paiici- 

 i^landulosa, F v. M., may be mentioned as a variety founded 

 partly on the nuineiical inlcriority ol the glands. 



