OF ARTS AND SCIENCES. 11 



Zexmenia fasciculata, Schultz Bip. in Seem. Bot. Herald, 306, 

 taken up later by Hemsley, is not wholly " discoid " as DeCandoUe 

 states, some of Berlandier's own specimens having rays. Perhaps it 

 too nearly approaches the narrower-leaved forms of Z. ceanothifolia, 

 Schultz, at least as to the Lipochata umbellata, DC, of Berlandier's 

 collections. 



Zexmenia crocea, Gray, PI. Wright, i. 114. To this belongs 



Z. sienantha, Hemsley, Biol. Centr.-Am. Bot. ii. 147. The narrow 



disk-corollas are common to all the species of this Lasianthcea group. 



From the specific name, it is probable that the unpublished Z. tageti- 



jiora of Don, enumerated in Steudel's Nomenclator, is of this species. 



Zexmenia helianthoides, Gray, 1. c. To this must belong the 

 Tithonia ovata, Hook. Bot. Mag. t. 3901, referred to the genus by 

 Bentham, and taken up as Z. ovata, Benth. & Hook., by Hemsley. 



Verbesina, L., partly. It is no longer practicable to keep Actino- 

 meris apart from Verbesina upon the character of neutral or infertile 

 (although styliferous) rays. Yet the former genus may be kept up 

 for the species upon which Nuttall really established it, relying 

 mainly on the globose head, becoming squarrose in fruit, and the 

 simple small involucre. For the rest, there is neither character nor 

 habit to distinguish the species from Verbesina. The North American 

 and Mexican species known to me fall under the following sections or 

 subgenera. 



§ 1. Verbesinaria, DC. Capitula sat angusta, parvula, sfppius cymo- 

 so-aggregata vel paniculata : involucrum imbricatum : ligiilffl baud 

 numeroste plerumque fertiles, rarius nuUaj : aristae pappi baud 

 hamatfe. 



* Achenia prorsus aptera : receptaculum fere planum: ligulas 1-5 



cum fl. disci luteae : folia opposita secus caulem decurrentia. 

 V. occidentalis, Walt. Car. 213, a name to be restored for V. 

 Siegesbeckia, Michx. Besides being the oldest name under the genus, 

 this is Siegesbeckia occidentalis, L. Atlantic U. S. 



* * Achenia omnia vel nonnulla alata : receptaculum convexum vel 



conicum. 



V. ViRGiNiCA, L., is the only N. American species (of the Atlantic 

 States) ; it has small white-flowered and S-o-lisulate heads. It 

 includes V. microptera and V. potycephala, DC, and as a var. (lacini- 

 ata) V. laciniata, Nutt., which is V. sinuata, Ell. Also, as an anoma- 

 lous form, — 



Var. Palmeri Vegetior, viridior ; foliis majoribus (semi- ad sub- 



