Membranaceous, Membranous. Thin and rather soft and more or less translucent.
Meniscoid. Concavo-convex.
Mericarp. One of the achene-like carpels of Umbelliferæ.
-merous. In composition, having parts, as 2-merous, having two parts of each kind.
Micropyle. The point upon the seed at which was the orifice of the ovule.
Microspore. The smaller kind of spore in Selaginellaceæ, etc.
Midrib. The central or main rib of a leaf.
Mitriform. Shaped like a mitre or cap.
Monadelphous (stamens). United by their filaments into a tube or column.
Moniliform. Resembling a string of beads; cylindrical with contractions at intervals.