202 PEOCEEDINGS OF THE AMERICAN ACADEMY 



A little scai'ious chaff on the recejitacle is not uncommon in H. 

 nudijlorum and I believe in H. autumnale also. An arrangement 

 of the known species is subjoined.* 



* HELENIUM Linn. 



§ 1. EuHELENiUM. Ligulse fertiles, rarissime imperfeote styliferje vel neutrae, 

 ssepius nutantes. CoroUae disci tubo proprio brevissimo vel subnullo. Pappi 

 palese baud dissectae. Caules plerumque ramosi. 



* Annua vel biennia ; capitulis parvulis nunc mediocribus ; coroUis disci in 

 eadeni stirpe 4-5-dentatis. 



-1- Pappus brevissimus, e paleis rotundatis ecostatis muticis. 



1. H. QUADRiDENTATOM Labill. Foliis inferioribus saepius laciniato-pinnati- 

 fidis ; capitulo elongate, nempe disco oblongo-ovato ligulis plerumque duplo 

 longiore ; receptaculo oblongo-cylindraceo. — 8- Atlantic States to Mexico. 



2. H. MiCROCEPHALUM DC. Gracile ; foliis angustis, radicalibus pinnatifidis ; 

 capitulis corymbosis vel pauiculatis parvis; disco globosoligulaspaullo parumve 

 superante ; receptaculo ovato vel subgloboso. — //. heterophyUiim DC. Prodr., 

 quoad stirp. Berland. no. 2113. H. Texannm Buckley. — Var. bicolor Torr. & 

 Graj'. H. elegans DC. 1. c. — Texas and adjacent parts of ilexico, to Tanto^'uca, 

 Ervendberg. Var. bicolor has a more dejiressed globular bead, and the recep- 

 tacle approaching hemispherical instead of ovate ; but it is similar in some speci- 

 mens of the ordinary form. De Candolle's //. fieferojihi/llnm is, at least mainly, 

 represented in his herbarium by Berlandier's no. 2113, from Keynosa, Tamau- 

 lipas, which is the same as his no. 1429, from Laredo, Texas ; but the character 

 of the pappus in the Prodromus is inapplicable to this species. 



3. H. AMPHiBOLDM. Major; foliis radicalibus ignotis, superioribus remote 

 denticulatis vel integerrimis ; capitulis sparsis longius pedunculatis ; disco glo- 

 boso subdepresso ligulis rite evolutis breviore ; receptaculo ultra-hemisphaerico. 

 — H. Mexicanum DC. Prodr. 5, p. 666 (ex char, pappi, etc), non IIBK. — 

 Mexico. State of Chihuahua, near Monterey, Berlandier (no. 145 coll. anno 

 1828), Dr. Gregg; and near Saltillo, Dr. Gregg. — Head nearly twice the size 

 of the preceding species; the rays from fully half to at least a third of an inch 

 long. EeceiJtacle 2 lines high and almost 3 lines wide, forming nearly two-tliirds 

 of a sphere. 



+- -1- Pappus mediocris, e paleis obtusis muticis, costa vix uUa : receptaculum 

 ovoideo-conicum acutiusculum. 



4. H. oocLiNiuM. Tenuiter pubendum ; caide coryraboso-ramoso ; foliis 

 lineari-lanceolatis remote denticulatis (imis ignotis); ligulis pauciusculis disco 

 ovato-globoso diraidio brevioribus ; pappi paleis corolla disci -J-f brevioribus 

 oblongo-ovatis achenio subsequilongis. — State of Chihuahua, Mexico, in the 

 Nazas Valley, Bolson di Mapirai, Dr. Gregg. — Herb doubtless 2 feet high, and 

 with the aspect of the preceding, except that the rays are shorter (2 or 3 lines 

 long), and the disk (often half an inch high and fuscous) inclined to ovoid. The 

 well-developed receptacle is 4 lines high, and ovate-conical. This may be Do 

 Candolle's //. hefpro/ihi/llum in part, as that is said to have a " capitidum 

 ovato-globosum " and pappus twice or thrice shorter than the corolla, but this 



