aFunnelform(Bot) Having the form of a funnel, or tunnel; that is, expanding gradually from the bottom upward, as the corolla of some flowers; infundibuliform.
Century Dictionary and Cyclopedia
funnelformHaving the form of a funnel, or inverted hollow cone; specifically, in botany, applied to a monopetalous corolla shaped like a funnel, in which the tube enlarges gradually from below, but expands widely at the summit; infundibuliform.
Perianth tubular or funnelform.
"The Manual of the Botany of the Northern United States" by Asa Gray