LEGUMINOS^. 



Ill 



flows from wounds lua.l.- in ilic trunk and l.rancliPs. It also flows from the 

 roots, and is found l.v digi,nn<,' about th(3 foot ..f thn treo. Much of this 

 resiu that comes to market is fossil, as it is freciuently found where there are 

 no trees. 



^farts. — Tho. ports of export are Aden, in sonthcrn Arabia, Alexandria, 

 and ports of the East and West Indies. 



ACACIA, Necker. Flowers regular, perfect or polygamous. Calyx 

 ■t-.Vtoothed. Petals uuited below. »Staniens free or united below, 

 numerous, longer than the corolla. Anthers small. Style thread- 

 like. Pod sometimes two-valved, and at other times not openhig when 

 ripe ; flattened or cylinilrical, contahiing many flattened seeds. Leaves 

 bi-pinnate ; leaflets small ; stipules frequently spinous. Flowers small, 

 in globular heads or cylindrical spikes, axillary, and yellow. Shrubs 

 or small trees, usually armed with prickles or thorns. 



A. Senegal, Willd. (Gum Arabic.) Stem 20 feet high, erect. Branches 

 irregular, crooked, and twisted, the young brauchlets tiucke.ned at the 

 nodes, which are armed with tln-ee hooked 

 thorns. Bark smootli, grayish, or white. 

 Leaves alternate, or appearing in bunches, 

 or fascicles, bi-pinnate ; rachis slender, 

 tomentose, terminated with a gland, hav- 

 ing one also at the base ; pinnje opposite, 

 3 to 5 pairs ; leaflets opposite, 10 to 20 

 pairs, sessile and linear-ol)long, rigid, 

 grayish-green, one sixth of an inch long. 

 Flowers axillary, sessile, small, in slender, 

 cylindrical, erect spikes. Calyx liell- 

 shaped, downy, cut into 5 acute segments, 

 reaching half-way down. Corolla campan- 

 nlate, twice as long as the calyx, divisions 

 extending half-way down. Stamens nu- 

 merous ; filaments slender, erect, 3 times 

 the length of corolla, yellowish, united at 

 the base into a short tube, which is in- 

 serted on the base of corolla. Anthers 

 small and roundish. Ovary on a sliort 

 stalk, small, oldong. Style filiform, 

 shorter than stamens ; stigma terminal. 

 Pod short-.stalked, 3 to 4 inches long, and 



three fourths of an inch wide, constricted between the seeds, smooth, ])ale, 

 membranous, witli a strong marginal ril). No. of seeds 2-G ; funiculus long; 

 beans roundish, mucli flattened. l)rown. 



There are over 400 si)ecies of this i^cinis. but the pure (Jum Arabic is from 

 the A. Senrgn!, found in Kordofan. 



Geograpin/. — The geographical di.stribution of the acacia is very extensive. 

 It occupies a broad belt both sides of the equator, all around the globe. 

 Though it is for the niost part a tropical and subtropical plant, it reaches 

 far into the temperate zones. Many species grow in Australia, and some in 

 America. Most of the species, however, are found in tropical Africa and 

 Asia, and in the tropical Pacific Islands. 



Acacia Senegal (Gum Arabic). 



