198 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 



4. Callitriche auturanalis L. 



In shallow water; Great Falls, Md., May, 1899 (Steele). Widely distributed in N. 

 Amer., Eur., and Asia. (C. bifida Morong.) 



92. IIMANTHACEAE. 



1. FLOERKEA Willd. 

 1. Floerkea proserpinacoides Willd. False mermaid 



Eastern^ 8 nd ' bGl ° W ^^ RUn ' *"* PIummers Mand - Apr.-May. 



93. ANACAEDIACEAE. Sumac Family. 



The smoke tree, CoHnus coggyria Scop., is cultivated for its attractive feathery 

 fruiting panicles and highly colored autumn foliage. 



Fruit whitish, glabrous or sparsely pubescent; slone striate; small trees, shrubs 

 or climbing vines, poisonous 1o (he 1ouch. Leaflets 3-13. 



v •♦ -ij- t. 1 - TOXICODENDRON. 



Fruit reddish or purplish, densely pubescent; stone smooth; shrubs or small trees not 

 poisonous. 



Flowers in dense terminal panicles, appearing after Ihe leaves; leaflets more than 3. 

 Flowers in clustered spikes, appearing before the leaves; leaflets 3. 2 ' RHUS ' 



3. SCHMALTZIA. 

 1. TOXICODENDRON Mill. 



Leaflets 7-]3; tall shrubs, sometimes treelike j T vernix 



Leaflets 3; low shrubs, suberect and scrambling, or climbing 7o considerable heights! 



, _ . 2. T. radicans. 



1 Toxicodendron vernix (L.) Kuntze. Poison SUMAC 



Swamps; frequent. July. Eastern U. S. (Rhus venenata DC; R. vernix L ) 



This is the most poisonous species. 

 2. Toxicodendron radicans (L.) Kuntze. Poison ivy 



Woods or open fields; common. May-June. Eastern U. S. (Rhus radicans L ) 



The typical form is a low erect pubescent plant. Very often, however, the plants 

 are climbing and glabiate. The latter form is T. pubescent Mill. (Rhus toxicoden- 

 dron L.; T. toxicodendron Britton.) 



2. RHUS L. Sumac. 



Rachis of the leaf wine-margined ■■ *» 



t, ,. .,, , „ . e l.K. copallma. 



Rachis of the leaf not winged. 



Foliage and twigs velvety-pubescent 2 E hht& 



Foliage and twigs glabrous .".".'"" ~ """" *a R elab 



1. Rhus copallina L. r. 



•n T ■, - , , DWAKF SUMAC. 



\\ oods or open fields, preferring dry situations; common. July. Eastern U S 

 A shrub usually 1-2 meters high ; leaflets glabrous on the upper surface. Sometimes 

 known- as black sumac. 



2. Rhus hirta (L.) Sudw o 



V l ouuw. Staghorn sumac. 



Dry rocky soil; frequent. Juno. Eastern N. Amer. (R. typhina L ) 

 This species has orange-colored wood and is ordinarily a shrub 2-5 meters high. 



3. Rhus glabra L. , TT 



n ■? , , White sumac 



Dry soil; common. July. Eastern N. Amer. 



A shrub 1-3 meters high. Known also as scarlet or smooth sumac. The leaves like 

 those of other species, are sometimes used for tanning. 



