254 Mi\ D. Don's Descriptions of new Genera and Species 



2. D.? A-erro^a, foliis ovato-lanceolatis acutis dentato-serratis 

 penninerviis, floribus glomeratis. 

 Carduus mitis. Herb. S. et M. 

 In Mexico. Sesse et Mocinno. ^ . 



Frutex erectus, ramosus. 'Rami sulcato-angulati, undique om- 

 nin^ albo-lanati. Folia alterna, brevissim^ petiolata, spitha- 

 maea, ovato-lanceolata, acuta, dentato-serrata, dentibus tri- 

 angulari-ovatis, mucronatis, leviter antrorsiim uncinatis, aliis 

 ' minimis interjectis, penninervia, nervis obliqu^ transversis, 

 costdque media validd prominentibus, supr^ demiim calva, 

 viridia, punctisque elevatis copiosissimis asperiuscula, sub- 

 t^s land albA, dens^ implex^ copiosissimb vestita, 5 — 7- 

 pollicaria, 2 — 3 uncias lata, basi acuta integerrimd. Petioli 

 crassi, brevissimi, vix sesquilineam longi. Flores terminales, 

 plures (5 — 10), sessiles, glomerati. Involucra globosa, dens^ 

 lanata: squamis multiplici ordine lanceolatis, acuminatis, 

 rigidis, adpressis. Receptaculum planum, scrobiculatum, 

 angulis elevatis, acutis exasperatum. Flosculi perfecti non- 

 diim observati : pappo setaceo, scabro. 



Having only seen specimens of this with the capitula in a very 

 young state, it has been placed here solely from the habit of the 

 plant itself and from the structure of its involucrum. What relates 

 to the florets still remains undetermined. 



Centroclinium. 



Receptaculum aculeatum. Flosculi disci tubulosi, hermaphroditi ; 

 radii ligulati, foeminei. 



Involucrum subglobosum, multiplici ordine imbricatum : squamis 

 lanceolatis, acuminatis, coriaceis, adpressis. Receptaculum 

 aculeatum : aculeis subulatis, callosis, rigidis, brevibus, in 

 circulis plurimis dispositis. Flosculi disci hermaphroditi, 



tubulosi, 



