GENUS 98. 



THISTLE FAMILY. 



535 



98. HAPLOESTHES A. Gray, Mem. Am. Acad. (II) 4: 109. 1849. 



Perennial caulescent, partly woody and partly fleshy plants, with opposite narrow entire 

 leaves, the lower connate-sheathing, and corymbose heterogamous radiate heads. Invo- 

 lucre of few broad many-nerved bracts. Receptacle flat or slightly convex, naked. Ray- 

 flowers pistillate, fertile, the rays yellow, spreading or recurved. Disk-flowers perfect, fertile. 

 Anthers obtuse and entire at the base. Style-branches of the disk-flowers capitate-truncate. 

 Achenes narrow, lo-ribbed. Pappus of I series Of slender scabrous bristles. [Greek, simple 

 garment, the involucre composed of few bracts.] 



A monotypic genus of the south-central United States and Mexico. 



i. Haploesthes Greggii A. Gray. Gregg's 

 Haploesthes. Fig. 4604. 



Haploesthes Greggii A. Gray, Mem. Am. Acad. (II) 

 4: 109. 1849. 



Stems usually branched at the base, the branches 

 i-2 tall, glabrous, striate, corymbose above. 

 Leaves fleshy, the lower ones connate and sheath- 

 ing the stem, narrowly linear or linear-filiform, 

 |'-2' long, entire ; heads short-peduncled, few to- 

 gether in cymes; involucres ii"-2" high, the bracts 

 oval to orbicular, rounded at the apex, thin-mar- 

 gined; rays yellow, i"-2" long; achenes i" long. 



In saline and gypsum soil, Kansas and southern 

 Colorado to Texas and Mexico. April-Sept. 



99. ERECHTITES Raf. Fl. Ludov. 65. 1817. 



Erect, usually branching herbs, with alternate leaves, and (in our species) rather large 

 discoid many-flowered heads of whitish flowers, corymbose-paniculate at the ends of the 

 stem and branches. Involucre cylindric, swollen at the base, its principal bracts in i series, 

 linear, with or without some much smaller outer ones. Receptacle concave, naked. Marginal 

 flowers in 2-several series, pistillate, fertile, their corollas filiform, the limb 2-4-toothed. 

 Central flowers perfect, fertile ; corolla narrowly tubular, the limb 4-S-toothed, the style- 

 branches elongated, truncate or obtuse at the summit. Anthers obtuse and entire at the base. 

 Achenes linear-oblong, angled or striate. Pappus of copious capillary soft smooth white 

 bristles. [Ancient name of some groundsel.! 



About 12 species, natives of America and Australasia, 

 species known to occur in North America. 



The following typical one is the only 



