DEVELOPMENT OF HEAD AND FLOWER OF 
DIPSACUS SYLVESTRIS 
CONTRIBUTIONS FROM THE HULL BOTANICAL LABORATORY 278 
HILtary S. JURICA 
(WITH FOURTEEN FIGURES) 
Introduction 
Epigyny and its occurrence among the upper Sympetalae have 
frequently been studied, but epigyny begins with the Rubiales, 
and while almost every family in this region has received attention 
in this regard, the Dipsaceae have been overlooked altogether. 
Accordingly this investigation was begun in an endeavor to fill 
this vacancy: During the course of the study, however, the 
development of the head was found to be interesting, and since it 
raised the question as to the relation the developing head bears 
to the general topography of the plant, it was thought best to 
include both of these phases in the present work. 
For the material used in this study I am indebted to the 
generosity of CHarLtEs C. Dream, State Forester of Indiana, who 
not only collected the necessary plants at repeated intervals, but 
also loaned a number of mounted specimens from his herbarium. 
The fresh material was killed in a stock solution of chromoacetic 
acid and stained for the greater part with safranin, Delafield’s 
haematoxylin, and orange G, the latter stain being omitted in a 
few cases. 
My acknowledgment is due to Professor CHARLES J. CHAMBER- 
LAIN, at whose suggestion the work was undertaken, for valuable 
assistance rendered during the course of the investigation. 
General topography 
Dipsacus sylvestris is a biennial propagated by seeds. During 
the first season the plant develops a very flat rosette of crinkled 
leaves (2). These are oblong to lance-shaped, obtuse, tapering 
at the base and scalloped toothed. The surface of the wrinkled 
Botanical Gazette, vol. 71] [138 
