276 The Natural System of Botany. 



the sweet, fragrant, and stimulant Balsam of Tolu. Thi s r - l 

 order also furnishes the most useful gums ; of which we ne I 

 only mention Gum Tragacanth, derived from Astragalus ver 

 of Persia, &c. ; and Gum Arabic, the produce of nurnerou 

 African species of Acacia. The best is said to be obtained 

 from A. vera, which extends from Senegal to Egypt ; foUi 

 Gum Senegal is yielded by Acacia Verek, and some other spe- 

 cies of the river Gambia. The Senna of commerce consists 

 of the leaves of several species of Cassia, of Egypt and Ara- 

 bia. More acrid, or even poisonous qualities, are often met 

 with in the order. The roots of Baptisia tinctoria, (called 

 wild Indigo, because it is said to yield a little of that substance) 

 of the Broom, and of the Dyers' weed, (Genista tinctoria, used 

 for dying yellow,) possess such qualities ; while the seeds of 

 Laburnum, &c, are even narcotico-acrid poisons. The 

 branches and leaves of Tephrosia, and the bark of the root of 

 Piscidia Erythrina, (Jamaica Dog-wood, which is also found 

 in Southern Florida,) are commonly used in the West Indies 

 for stupifying fish. Cow-itch is the stinging hairs of the pods 

 of Mucuna (or Stizolobium) pruriens, of the West, and M. 

 prurita of the East Indies. Among the numerous valuable tim- 

 ber-trees, our own Locust, (Robinia Pseudacacia,) must be 

 mentioned ; and also the Rose-wood of commerce, the produce 

 of a Brazilian species of Mimosa. Few orders furnish so many 

 plants cultivated for ornament." 



Order — Rosacea. The Rose Tribe. 



Whether considered in reference to the beauty and univer- 

 sal culture of some of its members, the usefulness of the medi- 

 cinal properties of many, or the excellence of the fruit of others, 

 this order is one of the most important of all. The specie? 

 are very numerous, and are generally natives of the temperate 

 regions of the Northern Hemisphere. 



The structure of the flower is nearly the same in all the or- 

 der, but from differences in the fructification, it has been divid- 

 ed into several families, or sub-orders. Taking the flower of 

 the Strawberry for examination, we find that the calyx con- 

 sists of five sepals, on the outside of which are five bracts. 



