1 -JO DAVENPORT ACADEMY OF NATURAL SCIENCES. 



florescence long pedunculate, diffusely thyrsoid, or compactly globose: 

 inclined to hybridize with other species of this group. 



Leaves triple-nerved. 



16. C. thyrsiflorus, Ksch. Central California, near the coast, with 

 three well-marked hybrid forms, viz. : 



a. C. thyrsiflorus X (?) = C. Lobbianus, Hook. 



b. C. thyrsiflorus x (?) = C. Veatchianus. Hook. 



c. C. thyrsiflorus X C. papillosus. 



Of this last only, have I sufficiently definite information to refer the 

 specimens collected to the two parent forms. These showing their 

 ordinary specific characters unchanged, were growing luxuriantly along 

 the sides of a wild mountain road, the low-branched C. papillosus being 

 often overtopped by its more aspiring rival, C. thyrsiflorus. The season 

 of flowering being the same in both, they were equally attractive to 

 swarming insects, the natural result being noticed in occasional dwarf 

 bushes partaking of a mixed character; thus, while the leaves conspicu- 

 ously veined beneath, show a tendency to triple nerves, these do not 

 extend to the base of the leaf, and towards the apex take on the penni- 

 nerved character of C. papillosus, but without papillae on the upper 

 surface. The inflorescence is after the compact pattern of C. papillosus. 

 and the fruit, which occasionally perfects its seed, is also nearest to the 

 latter species. From this instructive example I have little hesitation in 

 reducing the forms a. and b. to a similar origin, and thus relieve syste- 

 matic botany from the burden of carrying doubtful species, though it 

 will require direct field observation to assign them to their double 

 parentage. 



Leaves pejininerved. 



1 7. C. Parryi, Trelease, 1. c. I have little to add to the well-char- 

 acterized description of Professor Trelease, except to state that it has 

 been observed and abundantly collected the past season (1888), on 

 mountain slopes near Calistoga, where it is associated with C. foliosus. 

 It has also been detected from other remote localities, in early botani- 

 cal collections, so that it is probably of rather extended geographical 

 range. Unquestionably its nearest relations are with C. papillosus, 

 the chief points of difference being the absence of papillae, and a more 

 diffuse inflorescence. 



18. C. papillosus. Torr. & Gray. To include variety dentatus — C. 

 dentatus, Terr. & Gray, and variety floribundus = C.floribundus, Hook. 



