300 CONTRIBUTIONS FROM THti NATIONAL HERBARIUM. 



Keeled. Provided with a more or less sharp longitudinal ridge, like the keel of a boat 



Lacerate. Irregularly cleft, as if torn. 



Laciniate. "Slashed "; cut into slender pointed segments. 



Lanceolate. Lance-shaped; 3 or 4 times as long as broad and tapering from the basal 



third to a narrow apex. 

 Leaflet. A single division of a compound leaf. 

 Legume. The fruit of Caesalpiniaceae and Fabaceae, one-carpeled, usually dry, 



two-valved. and dehiscing along the back. 

 Leguminous. Pertaining to a legume, or to the families Fabaceae and Caesalpini- 

 aceae. 

 Lemma. The outer bract of the floret of grasses, called also the flowering glume. 

 Lenticular. Having the shape of a double-convex lens. 

 Ligule. A strap-shaped corolla, as in the ray flowers of Asteraceae; also, in grasses 



and a few other families, an appendage, usually membranaceous, on the inner side 



of the junction of the sheath and blade. 

 Limb. The expanded portion of a ganiopetalous corolla or calyx above the throat. 

 Linear. Many times longer than broad, and with the sides parallel or nearly so. 

 Lip. The upper or the lower division of a bilabiate corolla or calyx; the peculiar 



upper (apparently lower) petal in Orchidaceae. 

 Lobed. Divided to about the middle, or bearing lobes. 

 Lunate. Crescent-shaped. 

 Lyrate. Pinnatifid and having the terminal lobe rounded and much larger than the 



others. 

 Megasporangium. The receptacle in which me.^aspores develop. 

 Meejasporc. The larger of two kinds of spores borne by a plant, particularly in certain 



families of Pteridophyta, giving rise to the female prothallium. 

 Membranaceous. Thin, membrane-like, and somewhat translucent. 

 Micropyle. Orifice of the ovule, and the corresponding point on the seed. 

 Microsporangium. The receptacle in which microspores develop. 

 Microspore. The smaller of the two kinds of spores borne by a plant, especially in the 



Pteridophyta, giving rise to the male prothallium. 

 Midrib. The principal, usually middle, rib of a leaf. 

 Mid vein. The middle vein of a leaf or other leaflike organ. 



Monadelphous. Referring to stamens united by their filaments into a tube or column . 

 Monocotgledonous . Having a single cotyledon. 



Monoecious . Having stamens and pistils in separate flowers on the same- plant . 

 Mucro. A short straight abrupt tip. 

 Mucronate. Ending in a short straight abrupt tip. 

 Multifid. Very freely and deeply cut into narrow segments or lobes. 

 Muricate. Rough with short hard prominences. 

 Naked. Lacking organs or protective parts normally present in related species 



or genera. 

 Naturalized, Not native, but having become thoroughly established as a part of the 



flora of a region. 

 Node. The point upon a stem at which a leaf or whorl of leaves is borne, frequently 



hard and thickened. 

 Nodose. Marked by numerous or conspicuous nodes; knobby or knotty. 

 Nodulose. Marked by small knotlike or knoblike nodes or by partitions. 

 Nut. An indehiscent one-celled one-seeded fruit with a hard or bony pericarp. 

 Nutlet. A diminutive nut; one of the achene-like parts of the fruit of Boraginaceae. 



Verbenaceae. Menthaceae. etc. 

 Ob-. A Latin prefix, usually signifying inversion. 

 Obconic. Inversely conic, being attached at the slender end. 

 Oblanceolate . Inversely lanceolate, the broadest part being above the middle. 



