30 Hardy, Distvihntion of Leaf Glands in Acacias [v'ok'xxix. 



longer than broad, and the upper margin has usually a distinct 

 median angle surmounted by a small but prominent and some- 

 what trumpet-shaped gland. 



Other species with the gland well advanced from the base 

 are cultriformis and pravissima. The former, known as the 

 " Knife-leaved Acacia." has very heteromorphous phyllodes. 

 and the position of the gland varies accordmgly. When the 

 upper margin is only gently curved the gland is more often 

 nearer the base than when there is a pronounced curve of 

 small radius, as in the latter case the gland is usually above 

 this prominence. In A. pravissima there is a fairly constant, 

 distinct angle or abrupt curvv. about the middle of the upper 

 margin, and the gland is situated below this — usually about 

 half-way to the base, despite the varying shape of phyllode. 



Of the prickly acacias two may be mentioned — A. jiinipcrina 

 and A . verticillata — -the two being well separated in systematic 

 arrangement. In the absence of fruit and bloom, they bear 

 a strong resemblance to each other, the main distinction being 

 the pseudo-whorls of small rigid phyllodes of the latter and 

 the scattered, slightly larger phyllodes of the former. .1. 

 verticillata. has the gland usually about half-way along the 

 phyllode, which is about |--inch long, and A. jiinipcrina has it 

 almost constantly near the base. 



In a large number of the more xerophilous species, especially 

 those of the series Calamiformes, from North-West \'ictoria. the 

 marginal gland is either absent or very inconspicuous, even 

 when a hand lens is used. A. tigens and A. calami folia are 

 two of the exceptions, the gland being easily discernible. 



SuMM.^RY. — Glands in the genus Acacia are wanting in few 

 species, if any. They arc to be found almost exclusively on 

 the acroscopic or upper edge of the petiole or rhachis, or 

 phyllode. In Bipinnat;e they are in greatest quantity, most 

 frequently a gland for each pair of pinuc'e. situated close below 

 its base. They develop early in the life of the leaf. In the 

 PhyllodinCce the position is usually below the middle and 

 generally near the base of the i)hyllodc where the latter are 

 very long, while in much ])roportionately-broader leaves the 

 gland is usually higher up. Certain species arc prone to l)ear 

 two or more glands, and several have an auxiliary nerve con- 

 necting the marginal gland obliquely to the midrib, but this 

 feature is inconstant, and ap])arently restricted to species of 

 series Uninerves. Cjlands are absent from or most incon- 

 spicuous in species chiefly of the Calamiformes and others 

 having for habitat the drier north-west districts of Victoria, 

 though exceptions are giv^en. 



The following list gives approximately the groups into wliirli 

 many of the acacias lall il the usnnl Ideation ol flic Ljland is 

 taken as a guide. 



