FLOEA OF THE DISTRICT OF COLUMBIA. 193 



88. SIMAROUBACEAE. Quassia Family. 



1. AILANTHUS Deaf. 



1. Ailanthus altissima (Mill.) Swingle. Tree of heaven. 



Waste ground; frequent. June- July. Native of China; often cultivated and 

 becoming naturalized. {A. glandulosa Desf.) 



89. POLYGALACEAE. Milkwort Family. 



1. POLYGALA L. Milkwort. 



Flowers orange-yellow, in a dense head. Plants perennial or biennial . . .1. P. lutea. 

 Flowers not yellow. 

 Plants perennial. Flowers in a spike or raceme. 



Flowers white; leaves lanceolate 2. P. senega. 



Flowers rose-piirple; leaves, at least the lower ones, obovate or narrowly wedge- 



obovate 3. P. polygama. 



Plants annual. 

 Leaves all or partly whorled. 

 Flowers in long cylindric racemes 2-3 mm. thick. 



Leaves all whorled 4. P. vertieillata. 



Leaves except the lowest alternate 5. P. ambigua'. 



Flowers in dense oblong racemes 8-12 mm. thick 6. P. cruciata. 



Leaves all alternate. 



Stems with nearly all leaves reduced to scales. Flowers rose-purple. 



11. P. incamata. 

 Stems leafy. 

 Flowers rose-purple. 

 Bracts of the racemes persistent after the fall of the flowers. Racemes 10-12 



mm. thick 8. P. curtissil. 



Bracts of the racemes deciduous. 

 Wings 4.5-6 mm. long; pedicels much shorter than the pod. 



7. P. viridescens. 



Wings 3-3.5 mm. long; pedicels as long as the pod 9. P. mariana. 



Flowers greenish or nearly white. 

 Racemes thick-oblong; bracts of the racemes soon deciduous. 



7. P. viridescens. 

 Racemes conical; bracts persisting after the fall of the flowers. 



10. P. nuttaim. 



1. Polygala lutea L. Wild bachelor's-button. 

 Sandy swamps; vicinity of Laurel; near Smtland. June-Oct. Coastal Plain, 



Long Isl. to La. 



2. Polygala senega L. Seneca snakeroot. 

 Wooded hillsides; seemingly confined to the Piedmont Region. May-June. 



Northern states, south to N. C. 



The leaves vary considerably, ranging from lanceolate to ovate. The larger-leaved 

 form has been described as var. latifolia Torr. & Gray, but the forms so intergrade here 

 that it is impossible to draw a line of separation. The rootstock is listed as an official 

 drug in the U. S. Pharmacopcea. 



3. Polygala polygama Walt. 



Dry soil; Great Falls and Broadwater; apparently rare. June- July. Eastern N. 

 Amer. 

 Bears numerous small cleistogamous flowers on underground branches. 



69289—19 13 



