DIOECIA. OCTANDRIA. 239 



subturbinate, 5 to 8-parted, 3 to 5 of the seg- 

 ments interior. StaminaS to 8, (rarely 5.) Fem. 



Spiny trees, spines very larg-e, mostly axillary; prima- 

 ry leaves pinnate, succeeding- ones bipinnate; flowers ax- 

 illary, racemose, malt' flowers crowded; legume mostly 

 long" and falcate, multilocular, in G. monosperma l-seed- 

 ed. 



Species. 1. G. iriaca?iihos. Obs. A very deceptive tri- 

 vial name, the spines being not only trifid but often irre- 

 gularly and numerously compounded. The specific cha- 

 racter of G. horrida, of China, " trunk spiny, spines 

 branched," is a familiar appearance of G. triaconthos in 

 tr.e United States; the unimportant characier of spines 

 in this genus is sufiiciently evident in the ordinary occur- 

 - rer;ce of individuals of this species entirely v.'iihout 

 them. 2. monospertua. A smaller tree than the prece- 

 ding. 



Of this genus there appears to be another species indi- 

 genous to India and (Jliina, 



Order VIII.— OCTANDRIA. 



'96. POPULUS. X. (Poplar.) ^ 



Masc. dment cyUndric—CalLv consisting 

 of lacerated scales. C'oro/Za turbinate, oblique^ 

 and entire. Fem. Flower as in tlie male. Stig- 

 ma 4 or 6-lobed. Capsule 2 or 3-valved, Seeds 

 beset with long wool. 



Trees v.ith leaves which are roundish, or deltoidly cor- 

 date; petiole for the most part vertically compressed to- 

 wards the sum?!iit, and partly biglandniar, buds some- 

 times balsamiferous, floral ones earner tiian the leaves. 



Species. 1- P . balsamifera (Halsam Poplar.) 2. can- 

 (licans. 3- trepida. 4. tnonilifera. 5. hud>o?iica. Mich, 

 fli. P. betuUfolia. Ph. 6. gvandideinata. /3 *pendula. 

 Brrt.iches penrudous, as in ^iie Weep'rg A-,h "v v. On 

 the Aliegliany ridge, Pennsylvania; ]-are. 7. Icevigata. 

 B>. angulata. (" Cotton -T;ee.") Hab. Principally oj; the 

 alluvial banks of the the larger rivtii's of western America; 

 on the bank? of ti;e Viissislppi and iMissouri to their 

 sources. 9, heterophylla. 



