OP ARTS AND SCIENCES. 429 



trifidis vel 1-2-dentatis ; capitulis graciliter breviuscule pedunculatis 

 subcymosis ; involucre campanulato (lin. 3-4-longo), bracteis exterioris 

 angustis parvis, interioris oblongis 2-o-plo longioribus ; ligulis 5 inte- 

 gerrimis oblongis (lin. 3 longis) flavis, tubulo hispidulo ; fl. disci 6-10 ; 

 acheniis rectis subturgidis obovato-oblongis palea angusto-oblonga nunc 

 apice triloba scariosa parum superatis dorso glabris marginibus intus- 

 que longissime villosissimis ; pappo ex aristis 2 acbenio tKquilongis 

 b:;rbellatis. — Rio Blanco, banging loosely about rocks at tlie entrance 

 of caHons ; September. (530.) Tbis belongs to the Andean frutes- 

 cent group, the only one known in the northern hemisphere. Of 

 course the rays are neutral, as in all true members of this genus. 



Leptosyne Mexicana, Gray, n. sp. Perennis ; caulibus rigidulis 

 ultrapedalibus superne nudis oligocephaKs ; foliis filiformi-linearibus 

 integerrimis ; involucri exterioris bracteis oblongo-linearibus interiori- 

 bus subdimidio brevioribus ; ligulis 8-10 oblongis (lin. 4 longis) ; 

 acheniis orbicularibus subcoriaceis fere immarginatis glaberrimis calvis, 

 iis radii omnibus fertilibus. — Rio Blanco, along a rivulet in a grassy 

 bottom; September. (568.) A good Leptosyne, although not quite 

 of the typical section. The thickened tips of the style-branches have 

 a subulate appendage. 



Cosmos exiguus, Gray, n. sp. Glabra ; caule filiformi e radice 

 annua pedali 1-5-cephalo; foliis fere filiformibus integerrimis ; capitulo 

 paucifloro (florifero lin. 3 longo) ; bracteis exterioribus lato-subulatis 

 appressis, interioribus oblongis obtusis ; paleis receptaculi fructiferis 

 elongatis ; floribus atro-purpureis ; acheniis (5-G) lineas 8-9 longis 

 aristis 2 brevibus sursiim hirtello-barbellatis instructis. — Rio Blanco, 

 among grass and rocks; September. (559.) Like other annuals, it 

 probably occurs of larger growth. It must go with Cosmos, with 

 which it accords in everything except that the bristles of the pappus- 

 awns are upwardly barbellate. It is also Seemann's no. 1469 from 

 Cerro de Pinal, with some mature (longer) achenes, the awns similarly 

 hispid upwardly. 



Cosmos sulphureus, Cav. Ic. 1. 56, t. 79. (606 in the Cam- 

 bridge set, but a mistake.) 



Cosmos bipinnatus, Cav. Guadalajara, in fields, fence-rows, and 

 gardens ; September, October. (623, 699.) 



BiDF.NS chrysanthemoides, Michx. {jB. helianthoides, HBK.) 

 Guadalajara, in swamps ; July. (239.) 



BiDENS Palmeri, Gray, n. sp. Psilocarpcea, e grege B. angus- 

 tissimce et B. glaberrimcB (sp. ignota), prorsus glaberrima, ut vide- 

 tur perennis; caule pi uripedali rigidulo striato-angulato ; foliis rigidis 



