OF ARTS AND SCIENCES : JANUARY 26, 1870. 199 



tinn, Torr. Pacif. E. R. 5, p. 364. — In the same district as the preced- 

 ing, near Fort Yuma, Gen. Thomas. Tube of the involucre nearly 

 two lines long, cylindrical with an attenuated base. 



26. C. Watsoni, n. sp. Canescenti-pubescens ; foliis angusto- 

 spatbulatis lanceolatisve ; involucris subsparsis paniculatis, dentibus 5 

 valde ina?qualibus cum bracteis parvulis aceroso-subulatis cuspide 

 recurva superatis, unico (rarius duobus) majori seu foliaceo-ampliato 

 tubo cylindrico pedicelliformi la?vi nunc subrequilongo, caeteris subulatis 

 parvis ; tubo perigonii cylindrico ; stamiuibus 9 ; embryone recto, coty- 

 ledonibus linearibus radicula longioribus. — Nevada, on the borders of 

 the desert, Humboldt, Reese-River, and Grass valleys, Torrey, Stretch, 

 C. Watson in Clarence King's Expedition. Leaves small. Involucre 

 one and a half or at length two lines long, most of the five teeth about 

 half a line long, but the enlarged foliiform one oval, oblong, or lanceo- 

 late : sometimes two or three of them are more or less accrescent. 

 Flower on a slender pedicel. Seed linear-subulate. Cotyledons re- 

 markably long and slender. 



6. LASTARRLEA, Remy. 



Involucrum nullum. Flores cymoso-glomerati : perigonium coriaceo- 

 herbaceum, 6-dentatum, involucrum Chorizanthis admodum simulans, 

 dentibus subulatis cuspide recurva uncinata terminatis. Stamina 3, fauci 

 perigonii inserta, lobis interioribus opposita, brevia, utrinque dente 

 membranaceo seu filamento sterili comitata. Ovarium sessile. Ache- 

 nium triquetrum. Embryo subarcuatus, cotyledonibus angustis, ra- 

 dicula longioribus. — Herbula annua multicaulis, foliis linearibus, 

 floralibus bracteisve oblongis seu lanceolatis verticillatis cuspide 

 recurva uncinata armatis tenacibus. 



1. L. Chilensis, Remy in Gay, Fl. Chil. 5, p. 289, t. 58, f. 1 ; 

 DC. Prodr. 14, p. 186. Chili, Bertero, Gillies. — California, J. Blake: 

 station unknown ; but probably introduced at some time from Chili, 

 perhaps in the fleece of sheep and cattle, as the hooked cusps or short 

 and stout awns of the bracts and calyx are tenacious, and the joints 

 very fragile. 



7. PTEROSTEGIA, Fischer & Meyer. 



Involucrum monophyllum ! tenue, primum florem sessilem fulcrans 

 eodemque brevius, rotundatum, pi. m. bilobum, fructiferum valde am- 

 pliatum, scariosum, achenium laxe amplectens, vesiculosum, reticula- 



