G Contributions from the Gray Herbarium 



Blightly less than a third of the known species. They are herbs, 

 annual or perennial, in one section suffrutescenl a1 base, with per- 

 sistent wings and sepals, the keel bearing an infra-apical variously 

 lobed crest. In two African species (P. Pctitiana A. Rich, and 

 P. nilotica Chod.) of this subgenus there is, according to Chodat, 

 no cresl whatever. In P. paucifolia Willd., of our eastern states, 

 ;i member of the subgenus Cha?naebuxus, there is a strongly lobed 

 fimbriate crista, and in various Old World species of Chamaebuxus 

 there is a crest of varying complexity. 



The Middle American species of Orthopolygala divide naturally 

 into two sections. In one, confined to Central America, Mexico, 

 and the adjacent United States in North America (but occurring 

 also in South America), the upper cell of the capsule is dehiscent 

 between the narrow* wings, while the slightly shorter lower cell is 

 usually indehiscent and its seed generally unappendaged. In the 

 other section, including the bulk of the species, the capsule is wing- 

 less, equally 2-celled, and both cells are dehiscent. The species of 

 the latter section can be divided into very satisfactory groups on 

 characters of seed-pubescence and aril. In this as in the other sub- 

 genera emphasis has been laid in the present revision on seed- 

 rather than on stigma-characters as offering more easily observ- 

 able and definable and quite as trustworthy characters for the dis- 

 crimination of species. 



The present revision was begun and partially completed during 

 the summer of 1915 at the British Museum and at Kew Herbarium, 

 and my grateful thanks are due to Dr. A. B. Rendle and Dr. Otto 

 Stapf for the opportunity to study the collections under their charge 

 including many types of the utmost importance. Through the kind- 

 ness of Dr. Stapf fragments of several types were transmitted to the 

 Gray Herbarium, where the revision has been brought to completion, 

 and where the examination of an abundance of Mexican material has 

 led to corrections or fundamental alterations in my conception of 

 several species. While at the British Museum I was, through the 

 kindness of the Honorable William Fawcett, enabled also to study 

 the collection of Polygala in the herbarium of the Jamaica Botanic 

 Garden. Grateful acknowledgments are also due Dr. B. L. Robinson 

 for his interest and assistance in the publication of this revision. 



In nomenclature the International Code has been strictly fol- 

 lowed. The herbaria in which the specimens cited are located have 



