22i 



PITTONIA. 



difference in habit, as well as habitat, not susceptible of being 



construed as intermediate between them, or as a variety of 

 either. 



Tkifolium Gambelii, Nutt. PI. Gamb.; Proc. Philad. Acad. 

 iv. 8 (1848). There are unmistakable indications, in Nuttall's 

 description of this species, that he had before him among 

 other plants the true T. fucatumj but that to which he 

 ascribes trifid calyx-teeth, and which should be taken as the 

 type of T. Gambelii, would not seem to be referable either to 

 T.facatiim or T. flavuhim. Certain specimens in my her- 

 barium, which I am forced to regard as typical of T. Gam- 

 belii, are in general aspect more like 2\ jUivulnmj but the 

 heads are only 3 to 5-flowered; and, while the upper lip of 

 the calyx consists of two simple subulate teeth, the lower lip 

 is greatly eidarged and variously cleft into 6 or more long 

 subulate-setaceous segments, some of which may easily be 

 construed as the two segments of one bifid tooth, thus answer- 

 ing to Nuttall's account of the calyx in his species. The 

 type^ of T. Gambelii was of southern California; and my 

 specimens come from the eastern base of Mi Diablo, a part 

 of the country already become noted with me, as a locality in 

 which many plants, otherwise peculiar to southern California, 

 are found in abundance. 



Alyssum Americanum. Perennial, the rather slender suf- 

 frutescent stems tufted from a long tap root, leafy up to the 

 inflorescence and 5 to 8 inches high: herbage, even to the 

 sepals, canescent with a very dense and closely appressed 

 stellate pubescence, the lower face of the leaves even white: 

 leaves approximate, spatulate-obovate, acutish, 4 or 5 lines 

 long: flowers yellow, in a dense terminal corymb which in 

 fruit lengthens into a raceme: pods obovate, 1\ lines long, 

 tipped with a persistent style I line long. 



Collected on the Porcupine River, in the interior of northern 

 Alaska, 1891, by Mr. J. Henry Turner. The specimens are 

 m flower only, though with remains of the fruit of a former 



