Floral Form and Function in Asteridae

Focusing on members of the Asteridae, recent and current projects include studies of ontogenetic shifts in floral form and function in Scrophulariaceae and their systematic and evolutionary significance.  Mark Coykendahl's (MS 1999) study of Verbascum determined that the development provided confirmatory evidence of derived floral morphology in this genus, a marked departure from their originial interpretation as ancestral.  In prior work the flowers of Rhinanthoideae and Antirrhinoideae were found to have fundamental differences in floral development.  The genus Lindenbergia supposedly had Rhinanthoid morphology but was a full autotroph, whereas all other members of the subfamily are parasitic or hemiparasitic.   Specimens were collected in Thailand, and molecular studies in Claude dePamphilis' lab placed this genus basal to all parasitic members of the family.  The floral morphology concurs.  Other basal groups await study including the woody genus Paulownia.   In a recently completed study, the fringed marginal corollar appendages in Nymphoides (Menyanthaceae) were demonstrated to have a function of exerting an upward force in interaction with a water surface in addition to display.  Bruce Robart (PhD 2000, U. Pittsburgh Johnstown) studied the evolution of floral form and pollination among varieties of the alpine Pedicularis bracteosa, a study involving development, pollination biology, molecular systematics, and morphometrics. 

BACK to field research page.  BACK to Armstrong's main page.