OF ARTS AND SCIENCES : NOVEMBER 11, 1863. 187 



2. Species excluded from Streptanthus. 



S. sagittatus, Nutt. in Jour. Acad. Philad. 7, p. 12. The scanty 

 original specimens of Wyeth are in flower only. The S. sagittatus of 

 Hooker and Arnott, from the Snake Country (which in the suppl. to 

 Fl. N. Amer. vol. 1, was referred to S. angustifolius, Nutt.) is appar- 

 ently the same with smaller flowers. These specimens show a torulose 

 terete silique and oblong seeds, in which the cotyledons probably are 

 not truly accumbent. They are identical with Pachypodiurn ( Thelypo- 

 dium) sagittatum, Nutt. in Torr. & Gray, Fl. ; and so, likewise, we 

 may regard the larger-flowered specimens, until their fruit is known. 



S. angustifolius, Nutt. in Torr. & Gray, Fl. 1. c. To this certain 

 narrow-leaved and smaller-flowered forms of the preceding species 

 have been subsequently referred. But Nuttall's specimens, on which 

 the species was founded, belong to Turritis patida, Graham, which is 

 as good an Arahis as need be, — therefore Arabis patula. 



S. angustifolius, Gray in Proceed. Acad. Philad. March, 1863, p. 67, 

 coll. Hall and Harbour, no. 35, is Turritis hrachycarpa, Torr. & Gray, 

 FL, a short-fruited form of T. stricta, Graham, which is a true Arahis, 

 — A. Drummondi. 



S. virgatus, Nutt. in Torr. & Gray, Fl. 1. c, although not extant 



in any of our herbaria, I may rather confidently refer to Arabis retro- 



fracta, Graham (Tu7-ritis, Hook, etc.), and A. Holbollii, Hornem., 



probably the purple-red-flowered form which occurs west of the Rocky 



Mountains. 



S. arcuatus, Nutt. 1. c, which Mi*. Wallace and Dr. Brew^er have 

 also collected in California, is another genuine wing-seeded Arabis, — 

 A. arcuatus. 



These last, with Arabis hlepharophylla. Hook, (of which the fruit is 

 unknown), have short, oval or barely oblong anthers, and there is 

 nothing in their flowers to associate them especially with Streptanthus. 



S. petiolaris, Gray, PI. Fendl. &c. (to which belongs S. Brazoensis 

 of Buckley), having short anthers, &c., must be referred to the wing- 

 seeded division of Arabis, ■ — A. petiolaris. 



S. longifolius, Benth. PI. Hartw. and S. micranthus, Gray, PI. 

 Fendl. (which is perhaps a form of S. longifolius), with short anthers, 

 very nan-ow siliques, and wingless seeds, may probably be referred to 

 Arabis. But the valves are so carinate that the silique appears almost 

 tetragonal. 



S. linear if olius. Gray, PI. Fendl., has elongated acute anthers, in- 



