37 



COMPOSITAK. 



Vol. Ill 



perfect, or some of them only staminate, the corolla-limb 5-lobcd. Involucre ovoid, or 

 narrowly campanulate, its bracts coriaceous, imbricated in few series. Receptacle flat, convex 

 or conic, commonly foveolate. Anthers obtuse and entire at the base. Style-branches narrow, 

 flattened, their appendages slender. Achcnes terete, ribbed or 5-angled. Pappus of several 

 scales, those of the ray-flowers shorter than or equalling those of the disk. [Named from 

 Gutierrez, a noble Spanish family.] 



About 25 species, natives of western North America, Mexico and western South America. 

 Besides the following, several others occur in the western United States. Type species: Gutierrezia 

 linearifolia Lag. 



1. Gutierrezia Sarothrae (Pursh) Britton and Rusby. Broom-weed. Fig. 4190. 



Solidago S.arothrae Pursh, Fl. Am. Sept. 540. 1814. 

 Gutierrezia Euthamiae T.&G.F1. N. A. 2 : 193. 1S41. 

 Gutterrezia Sarothrae Britton & Rusby, Trans. N. V. 

 Acad. Sci. 7 : 10. 1887. 



Glabrous or minutely pubescent, bushy, woody 

 at the base, J-li high, the branches rigid, as- 

 cending. Leaves linear, J'-l4' long, "-1" wide, 

 acute; heads oblong, 1V-2" high, few-flowered, 

 usually in clusters of 2-5 at the ends of the 

 numerous branches; rays 1-6, scarcely 1" long; 

 scales of the pappus linear-oblong, subulate or 

 acuminate ; achenes pubescent. 



In dry or rocky soil. Manitoba and Minnesota to 

 western Nebraska, Kansas, Texas and Sonora, west to 

 Alberta and Utah. Adventive at Rochester, N. Y. 

 Far western plants formerly referred to this species 

 prove to be distinct. Rabbit-brush. Aug.-Sept. 



Gutierrezia linearis Rydb., of the Rocky Mountain 

 region, ranging eastward into Kansas and Nebraska, 

 differs in being more woody and has somewhat wider 

 leaves. 



11. AMPHIACHYRIS [DC] Nutt. Trans. Am. Phil. Soc. II. 7: 313. 1841. 



Erect, much branched, glabrous herbs, with small alternate entire leaves, and very 

 numerous small heads of both tubular and radiate yellow flowers, solitary or clustered at 

 the ends of the branches. Involucre ovoid or hemispheric, its bracts coriaceous, imbricated 

 in few series. Receptacle naked. Ray-flowers pistillate. Disk-flowers perfect, but sterile, 

 or staminate. Pappus of the ray-flowers obsolete or coroniform, that of the disk-flowers of 

 5-20 subulate scales or bristles somewhat united at the base. Achenes pubescent. [Greek, 

 chaff-around.] 



Two known species, natives of the south-central United States, the following typical. 



i. Amphiachyris dracunculoides (DC.) 

 Nutt. Amphiachyris. Fig-. 4191. 



Brachyris dracunculoides DC. Mem. Soc. Phys. Gen. 



7 : Part 2, 265. pi. 1. 1836. 

 Amphiachyris dracunculoides Nutt. Trans. Am. Phil. 



Soc. (II.) 7: 313. 1841. 



Annual, slender, much branched, 6'-i8' high, the 

 branches ascending. Leaves linear, 6"-i8" long, 

 l"-2" wide, acutish, the uppermost almost fili- 

 form ; heads solitary at the ends of short branches, 

 10-30-flowered, aDout 2" high ; involucre hemi- 

 spheric, its bracts oval, obtuse; rays 5-10, about 

 as long as the involucre ; disk-flowers mostly 

 staminate, their ovaries abortive, their pappus of 

 5-8 subulate aristate scales, united into a short 

 cup at the base. 



In dry soil, Missouri and Kansas to Texas and 

 New Mexico. Found adventive at Easton, Penna. 

 Sept.-Oct. 



