contracted into a thick and flattened petiole 1-1 3^ inches long, 

 to cuneate at base and spatulate, entire or with slightly wavy 

 margins, thick and densely-silvery-stellate, gradually passing 

 into spatulate, entire and small stem leaves 6-9 lines long 

 without proper petiole; racemes about 2-4 inches long with 

 several light-yellow flowers 3 lines long, ascending and in a 

 iiead in flower, in fruit pedicels S-shaped (with the letter laid 

 on its side), 6-8 lines long and slender; calyx lobes narrowly 

 elliptical and obtuse, 2>^ lines long, petals nearly linear and 3 

 lines long; pods (immature) on a short stipe, 1>4 lines high 

 i;nd 2 lines wide, obcompressed, oblately rovmded and almost 

 truncate at both ends, the stvle a little longer than the pod; 

 whole plant except the petals stellate-pubescent. No. 2367 

 Cusick. White clav hills. Willow Creek Malheur Co., Oregon, 

 at about 3000 feet' altitude. May 3, 1900. Dedicated to my 

 good friend Cusick. This has the aspect of a Physaria. but the 

 pods seem half mature and show a Uttle tendency to inflation. 



Tsomeris arborea Nutt. The typical form also occurs on 

 the Colorado Desert as well as the var. globosa Coville and 

 some times on the same plant. The variety is not a good one. 



Oxystvlis lutea Torrey. 



Purpus seems to have been the first botanist to collect this 

 plant in bloom, but his specimens were so poorly dried that 

 the character of the flowers is obscured. The writer had a 

 chance to study this in bloom the past season and to clear 

 up some mystery about it. It has the same habit as the other 

 annual species of this family such as Cleome sparsifolia, lutea, 

 and Polanisia, but it seems to prefer soil more nearly like that 

 frequented by the Cleomellas, i. e. alkaline soil with much< 

 sand in it. and gravel, growing with Nama, Chaenactis Xanti- 

 nna, the fleshy alkali-loving Phacelias, Atriplex canescens and 

 hymcnelytra. Suaeda, and Cuscuta salina(?). It never grows 

 in clayey and alkaline flats without drainage such as some 

 Cleomellas frequent. Flowers light-yellow, densely clustered ; 

 sepals margined but brown and acute only after anthesis : 

 petals barely clawed, oval-eltiptical, obtuse, concave, widely 

 spreading; style upturned, acicular; stamens spreading 

 and introrse and with subulate filaments; pods com- 

 posed of two obovate lobes on either side of the base of the 

 style, and at an angle to each other, didymous, smooth. These 

 characters were taken with the fresh specimens in my han-''?. 

 Oiher chnracters can be seen in the specimens. Blooms in 

 April. Amargosa Desert, May, 1907. 



