June, "I Haruv, DistyibHtion of Leaf Glands in Acacias. zj 



Tlierc are some bipinnate s])ecies which normally carry only 

 the lowest and the uppermost glands, the rhachial internodes 

 (between the bases of the other pairs ot ])inn;e) being without 

 them. This applies to A. data (the "Cedar Wattle" or 

 " Pepi)er-tie(; Acacia") and .-1. discolor (the "Sunshine 

 Wattle "). \n A. elata, which has leaves more than a foot in 

 length, the petiole is often more than four inches long and the 

 rhachis more than six inches. Here the petiolar gland is a 

 prominent cushion, with conspicuous pore, and situated nearer 

 the lowest pinuce than the leaf base, but remote from both • 

 and. although there is sometimes a smaller gland near the end 

 of the rhachis, below the base of the terminal pair of pinnae, 

 it is more often absent from Victorian-grown trees examined 

 by me. A . Bailcyana has very small leaves with comparatively 

 large glands, and frequently the petiolar gland is undeveloped. 

 Indeed, there is often no room for it when the lowest pair of 

 pinnae spring from the base of the leaf, which thus has no 

 bare petiole. In .1. discolor we have, as far as my ex})erience 

 shovvs, a greater variety in the petiolar gland, which, normally 

 about ^\,-inch 'ong. sometimes extends to :^-inch ; or two may 

 be longitudinally adjacent, or, again, two may be laterally 

 contiguous, while the small round gland near the r-ase of the 

 terminal jjair of pinna,' is generally present (Plate, fig. i). In the 

 varieties of .4 . dcciirrens. inckiding normalis. dealbafa, and 

 mollis, as already remarked, there is some, but less noticeable, 

 inconstancy. There may be rhachial internodes with no gland 

 at all, or such spaces may contain two, and these not necessarily 

 near the pinnct bases, but midway between or dividing the 

 spaces into thirds. Especially in var. mollis, in my garden 

 at Kew, one may notice the large number of leaves in which 

 there are two glands to each internode of the rhachis. In 

 plants of this variety, also, I have occasionally found two glands 

 on the rhachis laterally adjacent (fig. 3). In passing, I may 

 mention that in the leaves of the Cape Wattle — which, however, 

 is not an acacia, and is botanically known as Albizzia lophanta — 

 the beautifully-feathered leaves have a i)romin'ent i)etiolai" gland 

 and one near the end of the rhachis. thus resembling Acacia 

 elata more than the varieties of A. dcciirrens. 



In the development of the leaf the gland is distinctly 

 precocious. In A. elata, &c., long before the pinn;e ha\e spread 

 their leaflets, the gland, with its pore, is prominent. Indeed, it 

 is well in evidence before the young leaf has disengaged from 

 their warm, hirsute, mutual embrace the unexpanded ])inna' : 

 but on this i)oint and others I hope to have some noles to offer 

 at a later date. 



JuvK.Mii.K Pl.\nts .v.nd KHViiKsioN ak V Foli.\c;l\ — In passing 

 Ironi the bipinnate forms to the l'hyll<>dine;e, we may note, a 



