2 Addisonia 



increasing the number of blossoms. In cultivation under glass 

 a night temperature of 40° to 50° is sufficient. Some of the dwarf 

 species, such as Acacia armata (often cultivated under the name of 

 Acacia paradoxa), A. lineata, and A. Drmnmondii, are especially- 

 suitable for pot culture, making medium sized compact plants. 



Propagation may be effected by means of seeds, by cuttings, or 

 by grafting. The seeds should be sown in the propagating house, 

 preferably in the spring. Before sowing pour hot water over them, 

 allowing them to remain in the cooling liquid from twelve to forty- 

 eight hours; they are to be sown while still wet. The seeds thus 

 treated should germinate in from one to four weeks, depending on 

 the species. After germination they are pricked off into pots or 

 flats, and repotted as necessity arises. For cuttings, of such species 

 as may be propagated in this manner, select side shoots with a 

 heel, taken from the main stem; the wood should be half ripened, 

 the best time for this method of propagation being in June; no 

 bottom heat, or very little, is required. 



Besides their value as decorative plants, many of the acacias are 

 of economic importance. From A. Senegal most of the gum arable 

 of commerce is obtained; A. Catechu furnishes a drug or medicine; 

 from others are secured dyes and fibres, and the leaves of some are 

 used for culinary purposes. Some furnish valuable wood for furni- 

 ture and cabinet work. A. Seyal yielded the "shittim" wood of 

 the Bible, employed for the Ark of the Covenant; this wood, on 

 account of its lasting qualities, was used by the Egyptians for the 

 coffins of their kings. 



The knife-shaped acacia is a shrub of a bluish-grey hue, the 

 heads of bright yellow flowers borne in racemes. The phyllodes, 

 closely arranged upon the branches, are falcate-elliptic or almost 

 triangular, thick, up to an inch long and half an inch wide, the 

 apex acute, cuspidate, the base wedge-shaped or somewhat rounded; 

 the margins are thickened, and there is one nerve, not quite central, 

 the lateral nerves and veins anastomosing quite prominently; there 

 is a sessile gland on the upper edge below the middle, sometimes 

 at the apex of an angle. The heads, containing thirty to forty 

 flowers, are about three sixteenths of an inch in diameter, are on 

 stalks shorter than their diameter, and are arranged in short racemes 

 which are much longer than the phyllodes. The pods are brown, 

 with the margins vein-like, and are often constricted between the 

 seeds. The seeds are oblong and placed longitudinally. 



George V. Nash. 



Explanation of Plate. Fig. 1. — Flowering branch. Fig. 2. — Flower, X 4. 

 Fig. 3.— Pistil, X 4. Fig. 4.— Fruit. Fig. 5.— Seed. 



