GLOSSARY. 297 



Involucre. A bract or series of bracts subtending a flower-cluster or 



fruit-cluster, 

 Irregular. Said of flowers when the separate parts of each cycle are 



not of the same size and shape, (e, g. Locust,) 

 Lanceolate. Said of leaves when from four to six times as long as 



broad, the broadest part below the middle and tapering up- 

 ward or both upward and downward, (e, g. Black Willow.) 

 Larva, (pi, larvae) The worm-like stage of insects. 

 Layer. A shoot which, while attached to the plant, takes root at 



one or more places and forms a new plant, (Page 96.) 

 Leaf-mould. Decayed leaves and other organic matter constituting 



the forest floor, 



Leaflet. One of the wing divisions of a compound leaf. 

 Legume. A simple pod opening by both ventral and dorsal sutures; 



fruit of pea family, (e. g. Locust.) 

 Leguminous. Pertaining to the family Leguminosae; said of plants 



bearing legumes. 



Loam. Friable, mellow, rich soil containing much humus. 

 Lobe. A projection or division of a leaf not more than half the depth 



of the wing. 

 Lyrate. A pinnatifid leaf of an obovate or spatulate outline with 



the end lobe large and roundish and the lower lobes small, 



(e. g. Bur Oak.) 



Manure. Plant food; any substance which promotes plant growth. 

 Monadelphom Said of stamens when united by their filaments in 



one group. 



Mono. Prefix meaning one: 

 Monoecious. Both staminate and pistillate 'flowers borne on the 



same plant, (e. g. Black Walnut.) 

 Mound-layering. (Page 96.) 

 Mulch. Any loose material that protects the soil from frost or 



evaporation. 

 Muskeg. A term commonly applied to sphagnum swamps by the 



Indians and woodsmen of northern Minnesota. 

 Nursery. A plot of ground set apart for the raising of plants that 



are to be transplanted elsewhere. An establishment for the 



raising of plants. 

 Obcordate. The i-e verse of cordate. 

 Oblanccolate. The reverse of lanceolate, 



Oblong. About twice as long as broad with nearly parallel sides. 

 Obovate. The reverse of ovate. 



Obtuse. Blunt, not acute, (e, g, leaflets of Locust.) 

 Odd-pinnate. Applied to pinnately compound leaves having a termi- 

 nal leaflet, (e, g. Ash.) 



