OP ARTS AND SCIENCES. 73 



Gaillardia acaulis. Naua, perennis, puberula ; foliis in caudice 

 subcrasso multicipiti confertis crassiusculis obovatis petiolatis margine 

 uudulatis vel subdentatis ; scapo prorsus nudo subspithaumeo mono- 

 cephalo ; iavoliuTO disco breviore, squamis extiniis ova!o-oblongis, 

 intimis lanceolatis tenuiter acuminatis ; floribus radii discique flavis ; 

 fiuibrillis receptaculi ovato-subulatis brevibus ; corollarum disci lobis 

 triangulari-ovatis obtusiusculis ; pappi paleis 9 ovali-oblongis omnibus 

 aristatis. — Southern Utah, Dr. Parry. A very remarkable dwarf 

 2")erennial species. Disk half an inch in diameter : ligules rather 

 numerous, hardly .half an inch long. 



Ch^exactis attenuata. Annua, glamluloso-subpuberula ; caule 

 spithamaBo corymboso-ramoso ; ramulis pedunculisve filiformibus ; fo- 

 liis paucipartitis filiformibus; involucro oblongo-cylindraceo 12-18- 

 floro, squamis angusto-linearibus apice filiformi-attenuatis ; recejitaculo 

 epaleato ; corollis albis, marginalibus vix ampliatis ; j:)appo conformi e 

 paleis 4 late obovato-cuneatis truncatis achenio coroliaque quadruplo 

 brevioribus. — Ehrenberg, Ai'izona, collected by A. E. Janvier, com- 

 municated by William M. Canby. Heads narrow, only 5 lines long. 

 This neat little species is closely related to G. carphocUnia Gray, with 

 which it agrees in having attenuated tips to the involucral scales, in this 

 more prolonged ; but the receptacle is naked, the heads narrow and 

 fewer-flowered, and the pappus throughout of very short and broad 

 pale£E. The now numerous species of Chcenactis may be discriminated 

 as follows : * — 



* CH^NACTIS DC. 

 § 1. EucH^XACTis. Pappus paleaceus. 



* Corollte flavae, extimae superne ampliatEe limbo pi. m. irregular!; involucri 

 squamffi obtusas vel obtusiusculse. 



t- Pappus simplex, e paleis 4 raro 5. 



1. C. LANOSA DC. Floccoso lanata, nunc denudata ; capitulo vix seraipoUi- 

 cari in pedunculo scapiformi 3-6-poIlicari. 



2. C. GLADRiuscuLA DC. Minus lanata, ramosa, magis foliosa ; capitulis 

 nunc subcorymbosis ■J-f-poUicaribus ; pedunculis validioribus 2-7-pollicaribus. 

 — Var. macrocephala Gray, in Bot. Whipp., forma mera validiori, = C. denudata 

 Nutt. Pi. Gamb. 



3. C. TENUiFOLiA Nutt. Pafum lanulosa, mox glabrata; caule ramoso 

 folioso ; capitulis circiter ^-poUicaribus subcorymbosis brevi-pedunculatis ; in- 

 volucri hemispliseiici squamis numerosis angustis ; acheniis breviusculis. — 

 C.JillJhUa Gray, PI. Fendl. p. 98? 



•*-■*- Pappus duplex (saltern fl. disci), e paleis 1-4 exterioribus cum 4 majoribus 

 alternantibus. 



4. C. HETEROCARPHA Gra7, PI. Fendl. p. 98. — Var. tanacetifolia. Nana; 



