Genus 85. 



THISTLE FAMILY. 



5'3 



4. Gaillardia suavis (A. Gray) Britt. & 

 Rusby. Rayless Gaillardia. Fig. 4548. 



Agassizia suavis A. Gray, Proc. Am. Acad. 1: 49. 1846. 

 Gaillardia simpler Scheele. Linnaea 22: 160. 1849. 

 Gaillardia suavis Britt. & Rusby, Trans. N. Y. Acad. Sci. 

 7: 11. 1887. 



Annual or biennial. Leaves in a basal tuft, or a 

 few near the base of the slender pubescent scape, 

 spatulate or obovate in outline, 2 - -6' long, pinnatifid, 

 dentate, or some of them entire; scape l-2 high, 

 monocephalous; head about 1' broad with the odor 

 of heliotrope, globose in fruit ; rays none, or short 

 and pistillate, or a few of them longer and neutral ; 

 bracts of the involucre oblong or lanceolate, spar- 

 ingly pubescent ; fimbrillae of the receptacle obso- 

 lete; style-appendages short, naked; achenes densely 

 villous; pappus scales broad, their awns very slender. 



In dry rocky soil, Kansas to Texas. April-June. 



86. BOEBERA Willd. Sp. PI. 3: 2125. 1804. 



Erect or diffuse, branching, annual, or perennial, strong-scented, more or less glandular 

 herbs, with opposite, mostly finely dissected leaves, and small peduncled heads of both tubular 

 and radiate yellow flowers. Involucre campanulate or nearly hemispheric, its bracts in 1 

 series, united into a cup, with small additional outer ones. Receptacle flat, pubescent. Ray- 

 flowers pistillate, the rays short. Disk-flowers perfect, their corollas 5-toothed. Anthers 

 entire or minutely 2-toothed at the base. Style-branches of the disk-flowers hirsute, apicu- 

 late. Achenes narrowly obpyramidal, 3-5-angled, striate. Pappus of about 10 scales, parted 

 to beyond the middle into numerous capillary, bristle-like segments. [In honor of J. von 

 Boeber, a Russian botanist, died 1820.] 



About 3 species, natives of the central United States and of Mexico, the following typical. 



i. Boebera papposa (Vent.) Rydb. Fetid Mari- 

 gold. False Dog-fennel. Fig. 4549. 



Tagetes papposa Vent. Hort. Cels. pi. 36. 1800. 

 Boebera chrysanthemoides Willd. Sp. PI. 3: 2125. 1804. 

 Dysodia chrysanthemoides Lag. Gen. et Sp. Nov. 29. 1816. 

 D. papposa Hitchc. Trans. St. Louis Acad. 5: 503. 1891. 

 B. papposa Rydb.; Britton, Manual 10 12. 1901. 



Annual, very leafy, glabrous or finely pubescent, 

 gland-dotted, much branched, 6'-l8' high, the branches 

 diffuse or erect. Leaves sessile, or short-petioled, i'-ii' 

 long, pinnately parted into linear or slightly spatulate, 

 sharply serrate or incised segments ; heads numerous, 

 short-peduncled, 3"~S" broad ; involucre campanulate. 

 of 8-10 appressed, oblong, obtuse, green or purplish, 

 glabrous or ciliate bracts, with several narrow shorter 

 outer ones; rays few, not longer than the width of the 

 disk; receptacle and achenes pubescent. 



Along streams and roadsides, Ohio to Minnesota, Mon- 

 tana, Louisiana, Mexico and Arizona. Occasionally found 

 as a weed in waste places in the Eastern and Middle States, 

 and in Ontario. Prairie-dogweed. July-Oct. 



87. THYMOPHYLLA Lag. Gen. et Sp. Nov. 25. 1816. 

 [Hymenatherum Cass. Bull. Soc. Philom. 1817: 12. 1817.] 



Annual or perennial herbs, some species low undershrubs, with gland-dotted foliage and 

 involucre, alternate or opposite leaves, and small heads of both tubular and radiate, mostly 

 yellow flowers. Involucre campanulate, its principal bracts united into a cup. sometimes 

 with smaller outer ones. Receptacle naked, or fimbrillate, not chaffy. Ray-flowers pistillate, 

 fertile. Disk-flowers perfect, fertile. Style-branches truncate or blunt. Achenes striate. 

 Pappus of several or numerous scales or bristles. [Greek, thyme-leaf, not applicable to the 

 following species.] 



About 15 species, natives of America. Besides the following, some 4 others occur in the west- 

 ern parts of the L'nited States. Type species: Thymophylla setifolia Lag. 



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