ROSE FAMILY. 115 



59. ACACIA. (Ancient Greek and Latin name of Acacia- trees ; one spe- 

 cies yields Gum Arabic.) No native species north of Texas. The following 

 are exotic shrubs or trees, cult, in conservatories N., and one of them planted 

 or run wild far S. 



1. Leaves twice pinnate, of very numerous small leaflets. 



A. Farnesiana. Native of South America : nat. along the Gulf of Mexi- 

 co, sometimes cult. : a nearly smooth shrub, with pairs of short prickles along 

 the branches, small linear leaflets, small heads, on short peduncles (2 or 3 to- 

 gether) of yellow very sweet-scented tlowers, used by the perfumers. The plant 

 also yields gum. Pod thick, pulpy or pithy within. 



A. dealjpata, of Australia : a fast-growing small tree, not prickly nor 

 thorny, pale or whitened with minute obscure down or mealiness ; with leaves 

 of 10-25 pairs of partial petioles (a little gland on the main petiole between 

 each pair), and very many pairs of closely set and minute linear leaflets ; the 

 bright yellow flowers in globular heads collected in an ample very open raceme 

 or panicle, odorous. 



2. Only the, leaves of the seedling twice-pinnate ; the rest simple and entire mostly 

 blade-like petioles (called pfiyllodia, Lessons, p. 69), standing edgewise 

 instead of flatwiw, but otherwise imitating rigid simple leaves. Chiefly 

 natives of Australia, where they are extremely numerous. 



# Leaves short, and with only a central nerve or midrib, 



- Linear awl-shaped or almost needle-shaped, prickly-tipped, small, about ' long. 

 A. juniperina. Rigid bushy shrub, with the leaves scattered over the 

 branches, and flowers in single small round heads. 



A. verticillata. Spreading shrub or low tree, with the loaves crowded 

 more or less in whorls of 5 - 8 or more, and flowers in cylindrical spikes. 

 -- * Obliquely oblong, lanceolate, or broader, not prickly-tipped. 



A. armata. Tall-growing shrub, usually with hairy branches, and with 

 conspicuous prickle-like stipules ; half-ovate oblong or incurved-lanceolate leaves 

 mostly blunt, with somewhat wavy margins, feather-veined, not over 1' long; 

 flowers in round heads. 



A. vestita. Tall-growing shrub, soft-downy, with drooping branches, pale 

 obliquely wedge-ovate or obovate and curved bristle-pointed leaves, and small 

 globular heads of flowers in racemes. 



A. CUltriformis. Shrub smooth, mealy-glaucous when young, with tri- 

 angular or lance-obovate and curved minutely pointed leaves, of thick and firm 

 texture, and globular heads in racemes, forming a leafy terminal panicle. 



# * Leaves 3' -6' or more long, pointless, with 2-5 parallel nerves, or when very 

 narrow only \-nerved : floiuers in slender loose or interrupted axillary spikes. 



A. Iongif61ia. Shrub or small tree, smooth, with angular branches, and 

 leaves varying from lance-oblong to linear, greatly varying, 2 - 5-nerved, often 

 faintly veiny between the nerves. 



A. linearis. Like the preceding, but with leaves (4'- 10' long) very nap. 

 row-linear and with only one obvious nerve. 



38. ROSACE^E, ROSE FAMILY. 



Plants with alternate stipulate leaves and regular flowers, with 

 usually indefinite unconnected ftamens inserted on the calyx, one, 

 few, or many simple separate pistils (except in the division to which 

 the Pear belongs), and single, few, or occasionally numerous seeds ; 

 these filled with a straight embryo. Destitute of noxious qualities 

 (excepting the bark, leaves, and kernels of some Cherries, and the- 

 like), and furnishing the most important fruits of temperate climates, 

 as well as the queen of flowers. We- have three principal great 

 divisions. 



