GLOSSARY. 273 



Undulate. — Wavy-margined. 



\'allecula (Pl. Vallecul/e). — A hollow; especially the grooves 



in the stem of Equiseiutn. 

 VALLECULAR.--Pertaining- to the valleculje. 



Vascular. —Containing vessels, ducts, etc., as the stems of ferns. 

 \'ein. — One of the small branches in the framework of a leaf. 

 Velum.— The indusium in Isoeies. 

 \'ENATI0N. — The manner in which the veins are arranged in the 



leaf. 

 \'ernation. —The arrangement of leaves in the bud. 

 \'IVIPAR0US. —Producing young upon various parts of the plant. 

 Whorl. — A circle ; as of leaves on a stem. 

 Winged. — Bordered with tissue, as the rachis of some ferns. 



