41 



altitude. On one cutover slope there was collected in 1931 and 

 1933 an albino form which differs from the type only in its 

 white corolla and a somewhat greater robustness. 



Phlox mesoleuca Greene f. alba f. now Leaves usually larger 

 (as long as 5.5 cm.), darker green, and more hirsute than the 

 type; corolla as wide as 3.8 cm. across and without a hint of the 

 typical rose coloration. 



Type specimens (Mueller no. 554) collected August 23, 1933 

 are preserved in the Field Museum of Natural History at Chi- 

 cago, Illinois and in the author's herbarium at Cuero, Texas. 



In a recent paper describing Talinum Youngae (Torreya 33: 

 148) the author unfortunately overlooked the close affinity of 

 the species for T. pulcheUum Woot. & Standi., a species known 

 only from the type locality at Queen, New Mexico. T. Youngae 

 and T. pulcheUum may be distinguished by the singly disposed 

 flowers of the latter on pedicels 1 cm. long in the axils of the 

 leaves as opposed to the usually 3-flowered cymes of T. Youngae 

 about 3 cm. long in the axils of the branches or terminal. 



It was suggested at the time of its description that T. 

 Youngae was closest related to T. calycinum Engelm. It seems, 

 however, that T. Youngae and T. pulcheUum form a natural 

 group as do T. calycinum and T. parviflorum HBK. They may 

 be distinguished as follows: 



Inflorescence much elongated (rarely shorter than 10 cm.; 



usually about 20 cm.) ; leaves terete 



T. calycinum, T. parviflorum. 



Inflorescence short (rarely 4 cm. long) ; leaves flattish. 



Flowers solitary in the axils of the leaves on pedicels 

 about 1 cm. long grouped near the top of the stem 

 and hardly surpassing the leaves. ... 7". pulcheUum. 

 Flowers usually 3 in cymes in the axils of the branches 

 or terminal, considerably surpassing the leaves but 

 rarely 4 cm. long T. Youngae. 



University of Texas 

 Austin, Tex. 



