182 < A1TAK1DACE.E. 



(lie leaves trifoliolate and petioled, or the upper floral simple. 

 Flowers in a terminal leafy raceme. 



Etymology. Name formed of 7toXijj, many, and aviaus, unequal; from 

 the number and inequality of the stamens. 



Geographical Distribution, &c. The genuine species of the genus, 

 founded by Rafinesque on Cleome dodecandra, Michx., belong to the warmer 

 parts of North America, of which P. graveolens alone is diffused northward 

 to the Great Lakes. — The species chosen for illustration is the P. trachy- 

 sperma, Torr. <5r Gray, 1. c. ; but the verrucose-rougheued surface of the 

 seeds, from which the name was taken, is not constant, and is sometimes 

 found in P. graveolens ; the flowers, also, vary greatly in size. The species, 

 however, is perfectly distinguished from P. graveolens, by the long style, 

 the more exserted stamens, and the entire absence of a stipe to the ovary 

 and pod. It would appear to accord very well with P. uniglandulosa, ex- 

 cept that the flowers are only one fourth the size of those delineated in the 

 original figure of that species by Cavanilles. 



PLATE 79. Polanisia trachy'sperma, Torr. cj- Gr. ; — summit of a 

 specimen in flower and fruit, of the natural size, raised in the 

 Cambridge Botanic Garden from Texan seeds, sent by Lindheimer. 



1. A flower, enlarged. 



2. Vertical section of a flower, more enlarged, through the ovary, &c. 



3. Transverse section of an ovary, magnified. 



4. An ovule, more magnified. 



5. A magnified seed (almost smooth). 



6. Section of the same, and of the contained embryo. 



