OF ARTS AND SCIENCES. 215 



cannot refer the plant to Sti/locline, nor suppress that genus without 

 also suppressing Psilocarphus. 



PLUMMERA, Nov. Gen. Coynpositarum. 



Capitula heterogama, pauciflora; fioribus radii foemineis ligulatis 

 2-5, disci niasculis 6-8. Involucruni obpyramidatum, cupuliforme, 

 cartilagiueo-coriaceum, duplex ; exterius e bracteis 4 ovatis oblongisve 

 obtusis dorso carinatis ultra medium usque scepius coalitis ; interius e 

 bracteis totidem alternantibus vix brevioribus liberis obovato-cuneatis 

 apice lato rotundato subseariosis. Receptaculura planum nudum, 

 Corollce radii lato-cuneata;, trilobae, sensim in tubum brevem angustataj ; 

 disci tubuloso-infundibuliformes, breviter obtuseque o-dentatae, extus 

 crebre glanduloso-pubentes, tubo proprio brevi crassiore. Antheraj basi 

 obtusaj. Stylus fl. disci apice brevissime bifidus, ramis baud stigmati- 

 feris, apice depresso-dilatato semi-peltato : ovarium inanum gracile. 

 Achenium fl. radii turgidum, obovatum, ecostatum, sursum pilis tenu- 

 issimis villosum, areola epigyna parva parum depressa: pappus 

 nullus. 



Pldmmera floribunda. Herba ut videtur biennis, bipedalis, 

 superue corymboso-ramosissima, foliosa, subglabra, odore et sapore 

 amaro-aromatica ; foliis omnibus tenuiter 1— 3-ternatim partitis, modo 

 Helenii et ActinellcB impresso-punctatis ; capitulis parvis perplurimis 

 fastigiato-cymosis plerisque pedunculatis ; floribus aureis. — Apache 

 Pass, S. Arizona, Mr. ^ 3Irs. Leminon. Dedicated to the latter, under 

 the name which she until recently bore ; the partner of her husband 

 in the severe labors and privations of Arizona exploration, and in the 

 honor of this and of many other interesting discoveries. The natural 

 affinity of this plant may rather be with Actinella in the Helenioidece ; 

 but the essential characters are wholly those of the Helianthoidece- 

 Milleriece. 



DUGESIA, Nov. Gen. Comp.-Melampodiearum. 



Capitula heterogama, radiata ; fl. radii 8-12 foemineis, disci pluri- 

 mis hermaphrodito-sterilibus. Involucrum latum, duplex ; exterius 

 foliaceum, e bracteis 6-8 obovatis oblongisve patentibus ; interius e 

 bracteis numerosioribus oblongis membranaceis erectis. Receptacu- 

 lum planum ; paleis angusto-linearibus scariosis planis apice dilatato 

 subherbaceis flores steriles subtendentibus, exterioribus ab acheniis et 

 bracteis invokicri subtendentibus omnino liberum. Corollaa radii 

 ligula plana cuneato-oblonga apice 2-3-fida e tubo brevi ; disci fere 



