162 Proceedin^s.s of the Ohio State Academy of Science 



It is troublesome from sprouting from the roots. Penn. and Ohio 

 to Ga., Iowa, Kan., and Okl. 



2. Robinia viscosa Vent. Clammy Locust. A small tree 

 with rough bark. Underground parts somewhat poisonous. Va. 

 to Ga. Also escaped in Middle and Eastern States. Ohio. 



Order, Geraniales. 



Rutaceae. Rue Family. 

 49. Xanthoxylum L. Prickly-ash. 



Trees or shrubs with punctate, odd-pinnate leaves and usually 

 with stipular spines. Capsule with 1-2 seeds. 



I. Xanthoxylum americanum Mill. Prickly-ash. A 

 prickly shrub or small tree with small flowers in sessile axillarv 

 cymes. Quebec to Va., S. Dak., Neb., Kan., and Ohio. 



50. Ptelea L. Hoptree. 



Shrubs or small trees with bitter bark. Fruit a samara with 

 a membranous wing. 



I. Ptelea trifoliata L. Hoptree. A shrub or small tree 

 with sunken superposed axillary buds covered by the petiole base. 

 Bark and flowers with a disagreeable odor. Conn, to Fla., Ont., 

 Minn., Kan., Tex., and Ohio. 



Simarubaceae. Ailanthus Family. 

 51. Ailanthus Desf. Ailanthus. 



Large trees with odd-pinnate leaves ; branches robust with 

 large brown pith. Samara linear or oblong, usually twisted. 



I. Ailanthus glandulosa Desf. Tree-of-heaven. A large 

 tree of rapid growth with thick branches and smooth bark. 

 Leaves ill-scented ; leaflets with green glands under the lobes or 

 teeth. Autumn leaves pure yellow. V ood hard and useful. 

 Sprouts freely from the roots and is easily propagated from root 

 cuttings. A pest in pastures in some states ; cows will not eat 

 grass near the young shoots. Water contaminated by the leaves 

 is poisonous. Naturalized from China. Ont. to Mass., Va., 

 Kan., and Ohio. 



