Psilactis

Psilactis Asters

Psilactis A. Gray is a small southwestern U.S. and Mexican genus of six species following Morgon (1993; Syst Bot 18: 290-308.) differing from other Symphyotrichinae. Species are annuals, biennials or rhizomatous perennials and have dimorphic cypselae with the ray fruit lacking a well developed crown of bristles. Species have been included in Machaeranthera (in the broad sense) in the past (Turner & Horne 1964). The relationships of Psilactis to other Symphyotrichinae taxa was explored by Morgan and Holland (2012); questions about the phylogenetic relationships of the genera and subgenera in the Symphyotrichinae remain unsettled. The treatment followed here is that of D.R. Morgan (2006 Flora North America.

Psilactis asteroides A. Gray
Psilactis brevilingulata Schultz-Bipontinus ex Hemsley
Psilactis gentryi (Standley) D.R. Morgan
Psilactis heterocarpa (R.L. Hartman & M.A. Lane) D.R. Morgan
Psilactis odysseus (G.L. Nesom) D.R. Morgan
Psilactis tenuis S. Watson

Morgan, D.R. and B. Holland. 2012. Systematics of Symphyotrichinae (Asteraceae: Astereae): Disagreements Between Two Nuclear Regions Suggest a Complex Evolutionary History. Syst. Bot. 37: 818–832.

revised 10 May 2013 by J.C. Semple