The Collaborative International Dictionary
Umbraculiform
Umbraculiform \Um*brac`u*li*form\, a. [L. umbraculum any thing that furnishes shade, a bower, umbrella (dim. of umbra a shade) + -form.] Having the form of anything that serves to shade, as a tree top, an umbrella, and the like; specifically (Bot.), having the form of an umbrella; umbrella-shaped.
Wiktionary
umbraculiform
a. (context botany English) Having the form of anything that serves to shade, such as a treetop or especially an umbrella.