John C. Semple    WAT                          

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  Bradburia Torr. & Gray 

The goldenaster genus Bradburia (Asteraceae: Astereae) includes two annual species native to eastern Texas (map).  Bradburia hirtella Torr. & Gray also has been reported from Louisiana. Bradburia pilosa (Nutt.) Semple [syn: Chrysopsis pilosa Nutt.] is common from central Texas to southwestern Missouri.

 Nesom (1991) placed both species in Chrysopsis, while Semple (1996) transferred C. pilosa to Bradburia.  In a cladistic study of the Chrysopsidinae, the two species of Bradburia always formed a clade that was never the sister group to Chrysopsis (Semple & Tebby, 1999. A cladistic analysis of subtribe Chrysopsidinae (Asteraceae: Astereae). XVI International Botanical Congress, August 1-7, 1999. St. Louis, MO. Abstract No. 2852; Poster No. 401.).  In most analyses, the Bradburia clade was sister group or part of the clade with Heterotheca and Croptilon. Recent unpublished DNA work indicates Bradburia is more closely related to Chrysopsis, but differs in pappus characteristics (Semple 2006 a, b).

Only the ray florets of Bradburia hirtella produce achenes which are not well adapted to long distance dispersal. The species is restricted to a narrow zone. In B. pilosa, both the rays and discs produce achenes.

SEMPLE, J.C. 2006. Bradburia Torrey & A. Gray. pp. 211-212. In Flora North America Editorial Committee, eds. Flora of North America. Vol. 20. Asteraceae, Part 2. Astereae and Senecioneae. Oxford University Press, New York.

Last update 5 March 2008 by J.C. Semple        © 2008, J.C. Semple