394 standley: north American amaranthaceae 



III. Centrostachydeae. Two genera of this tribe occur in North 

 America, Centrostachys and Cyathula. The group has always been 

 known as the Achyrantheae; but since the name Achyranthes must 

 be apphed to a genus of the Gomphreneae, as explained recently by 

 the writer/ it is necessary to form a new tribal name, typified by the 

 best known genus of the group. 



The Centrostachydeae reach their highest development in Africa, 

 the East Indies, and Australia. Two Old World species of Centro- 

 stachys have become established in tropical and subtropical North 

 America. Two species of C3^athula are found in the same region, C. 

 prostrata, a native of the Old World, being established in Jamaica and 

 Panama; while C. achyranthoides, an American species, occurs in the 

 Greater Antilles, where it may be adventive, and ranges from southern 

 Mexico to Panama, Brazil, and Chile. 



IV. Brayulineae. This is a new tribe, here proposed for the genus 

 Brayulinea, better known by thfe name Guilleminea, which, unfor- 

 tunately, is a homonym. The genus is related to the Gomphreneae, 

 with w^hich it has usually been placed, but is distinguished by the 

 perigynous androeciura. Apparently Dr. Schinz at one time con- 

 sidered this segregation, for in his key to the tribes of the Amarantha- 

 ceae in Engler and Prantl's Naturlichen Pflanzenfamilien^ he separates 

 the tribe Guillemineae. When the text for this part of the family ap- 

 peared, at a later date than the key, we find no mention of such a 

 tribe, the genus Guilleminea being referred to the Gomphreneae. 



In general appearance the species of Brayulinea are quite similar 

 to those of Gossypianthus. One species is found in North America. 



V. Froelichieae. It seems desirable to place the genus Froelichia. 

 in a tribe separate from the Gomphreneae, to which it has always 

 been referred. The group is characterized by the gamophyllous peri- 

 anth which becomes indurated and variously appendaged in fruit, 

 characters which are not found in any Gomphreneae. 



The genus is an American one, seven species occurring in southern 

 North America, with others in South America. Most of the species 

 are closely interrelated and are separated with difficulty. It is still a 

 matter of doubt how specific limits are to be determined with precision 

 in the genus. 



VI. Gomphreneae. Half of the North American genera of the 

 family fall into this tribe, which is, however, best represented in north- 



6 Journ. Wash. Acad. Sci. 5: 72-76. 1915. 

 «3i'': 97. 1893. 



