250 PROCEEDINGS OP THE AMERICAN ACADEMY 



sagittate. Pods more or less turgid, round or ovate or short-oblong 

 (often globose), with nerveless valves and a hyaline septum nerved 



less positively. In all our species there is a distinct nerve extending from the 

 apex to the middle of the septum or beyond. The filaments are never toothed 

 or appendaged; the petals are never narrowly unguiculate, and, except in one 

 or two species, are yellow ; the ovules are never solitary in the cells, and the 

 pubescence is always more or less stellate or lepidote. Among foreign species 

 the nerved septum is characteristic of the genus Lobularia (Koniga), as limited 

 by the exclusion of Ptilotrickum and by the peculiar appressed 2-forked pubes- 

 cence ; and in these, in addition to the midvein, the septum is covered with a 

 coarse network of veinlets which I have observed in none of ours, and its areolae 

 are straight and narrowly linear, to which our only approach is in V. globosa. 

 Phijsaria, which is included by Bentham & Hooker in Vesicaria, is certainly 

 to be separated, and the removal of the remaining American species is, in my 

 opinion, justified by the characters. We, moreover, thus avoid completely the 

 difficulties which beset the arrangement of the Old World genera, and leave the 

 question of our own one that can be answered with comparative ease. 



To the species that have hitherto been placed in Vesicaria,! would, therefore, 

 now give the generic name Lesquerella (in preference to reviving Lesquereuxia, 

 the former name of a genus now merged in Siphonostegia), in honor of our ven- 

 erable and in every way worthy veteran palaeontologist and bryologist, Leo 

 Lesquereux. Our one flat-podded species that has been referred to Alyssum 

 (A. Lescurii) appears to differ in no other respect than its less convex valves from 

 a somewhat distinct group of species which can be separated, however, only as 

 a section from the rest. I would arrange the known species of the genus as 

 follows : — 



§ 1. Altsmus. Not canescent or scarcely so, the pubescence loosely stellate. 



— Winter-annuals, the stems ascending or decumbent : filaments somewhat 

 dilated at base : pods globose, or suborbicular and flattened (in n. 1); cells mostly 

 6- or 8-ovuled. Tennessee and Texas. 



* Seeds margined : cauline leaves mostly auriculate : pods sessile. 



•*- Pods flattened (valves but slightly convex), strigose-hispid. 



1. L. Lescurii. Slender, branching : leaves oblong-ovate or oblong, toothed, 

 the cauline all auriculate : filaments abruptly dilated below : pods 2 or 3 lines 

 long, orbicular to broadly elliptical ; style not a line long ; cells 4-ovuled ; septum 

 dense. — Alyssum Lescurii, Gray. Near Nashville, Tenn. 



■*- -i- Pods globose, glabrous. 



2. L. grandiflora. Rather finely pubescent : lower leaves oblanceolate, 

 sinuate or sinuate-pinnatifid, the upper oblong to oblong-lanceolate : petals 

 obovate : filaments narrowed gradually above the base : pods suberect on divari- 

 cate pedicels; style a line long or less. — V. grandiflora, Hook. V. brevistyla, 

 Torr. & Gray. Middle Texas, from the Gulf to Red River. 



3. L. auriculata. More hirsute with spreading hairs : petals narrower : 

 filaments abruptly and broadly dilated at base: pods slightly narrowed at base. 



— V. auriculata, Engelm. & Gray. San Felipe, Texas (Lindheimer). 



