20 



MISC. PUBLICATION 110, U. S. DEPT. OF AGRICULTURE 



petal in the orchid family (Orchi- 

 dacese) . 

 Lobed: Incised, but with rounded 

 rather than sharp margins, and not 

 deeper than about halfway between 

 the outer edge and the blade center 

 — usually less ; said of leaves, petals, 

 etc. (Fig. 40.) 



Figure 40. — Lobed leaves : A, Pal- 

 mately lobed leaf, as in floating 

 pennywort e (Hydrocotyle ranimcu- 

 loides) ; B, pinnately lobed leaf, as 

 in certain oaks (Quercus spp.) 



Lodicule: One of two (occasionally 

 three) small hyaline scales, repre- 

 senting the corolla, found in the 

 florets of most grasses inside the 

 lemma and palea and subtending the 

 floral organs (pistil and stamens). 



Loment: A legume, or pod, constricted 

 between the seeds. 



Lorate: Shaped like a strap or thong 

 (lorum). 



Lunate: Crescent shaped (from luna, 

 moon ) . 



Lyrate: Lyre shaped; more or less 

 spatulate in outline but with two 

 or more small basal lobes. 



M.: Meter (s), approximately 39 inches, 

 or about 3% feet. 



Major quadrat: A square sample plot 

 of vegetation larger than the usual 

 1 square meter quadrat unit. 



Marcescent : Withering but not decidu- 

 ous, as shown, for example, in the 

 dried persistent leaves in certain 

 bunch-grass tufts. 



Membranaceous: Thin and translucent, 

 resembling a membrane; membran- 

 ous. 



Membranous: Of or pertaining to a 

 membrane ; membranelike ; mem- 

 branaceous. 



Mericarp: A division of a compound 

 fruit, especially one of the separate 

 1-seeded carpels of a schizocarp or 

 one of the dry pendulous halves of a 



cremocarp, or fruit of the umbellifer 

 (parsnip) family. Literally, part 

 fruit. 



Meristem: Growing tissue; embryonic 

 or undifferentiated portions of a 

 plant whose cells are capable of ac- 

 tive division. 



Meristematic: Of or pertaining to 

 meristem. 



-merous: A suffix (Greek, meros, part) 

 indicating division into parts. For 

 example, a typical 4-merous or tetra- 

 merous flower has 4 sepals, 4 petals, 

 4 stamens, and a 4-celled ovary. 



Mesocarp: The middle layer of a 3- 

 layered pericarp (outer covering of 

 a fruit). In a fleshy fruit, the same 

 as sarcocarp. 



Mesophyte: A plant that grows under 

 medium or average moisture Condi- 

 tions ; neither an aquatic (hydro- 

 phyte) nor a desert species (xero- 

 phyte). The vast majority of plants 

 growing in the United States are 

 mesophytes. 



Metabolic: Of or pertaining to me- 

 tabolism. 



Metabolism: The life processes of 

 plants as summed up in the chemical 

 and physical changes involved in 

 their growth, reproduction, and de- 

 cay. Metabolism may be construc- 

 tive (ahabolism) or destructive 

 (catabolism). 



Micro-: A prefix (Greek) signifying 

 small, or minute. It has in general 

 a rather more intensive significance 

 than the Latin prefix parvi-, and is 

 preferably applied to microscopic ob- 

 jects and parts. 



Micropyle: The minute opening of an 

 ovule through which the pollen tube 

 enters and fertilization is accom- 

 plished. In the seed the micropyle 

 is closed and usually persists as a 

 small scar. 



Migrant: That which migrates or has 

 migrated ; a plant which, by seed or 

 other means, invades a new area or 

 habitat. As a tree migrant in a 

 meadow. 



Migration: Invasion, or the movement 

 of plants into new areas. 



Milacre: A plot one-thousandth part 

 of an acre in extent, one-tenth of a 

 chain or 6.6 feet square ; containing 

 43.56 square feet. 



Mm. : Millimeter ( s) , approximately 

 one twenty-fifth of an inch. 



Monadelphous : Literally in one broth- 

 erhood ; said of stamens where all 

 in a flower are united by their fila- 

 ments into a single tubelike or col- 

 umnlike cluster. 



Moniliform: Resembling a string of 

 beads, as the moniliform roots 



