Journal article
STEPHANOSPERMUM-KONOPEONUS (LANGFORD) COMB-NOV - A MEDULLOSAN OVULE FROM THE MIDDLE PENNSYLVANIAN MAZON CREEK FLORA OF NORTHEASTERN ILLINOIS, USA
AN DRINNAN, JM SCHRAMKE, PR CRANE
Botanical Gazette | UNIV CHICAGO PRESS | Published : 1990
DOI: 10.1086/337839