278 American Midland Naturalist Monograph No. 2 



Hypogynous. Borne on the receptacle beneath the ovary; said of stamens and petals. 



Imbricate. Overlapping, as shingles on a roof. 



Incised. Sharply and more or less deeply and irregularly cut. 



Included. Not at all exserted or protruded, as stamens not projecting from the corolla. 



Indehiscent. Not opening regularly. 



Indurate. Hardened. 



Indusium. The covering of the sori of some ferns. 



Inferior. Said of an ovary when the other floral parts appear to be inserted upon it. 



Inflorescence. The arrangement of the flowers on the stem. 



Internode. The portion of the stem between two nodes. 



Introduced. Brought mtentionally from another country or region. 



Involucel. a secondary involucre; that subtending the umbellets in the umbelliferae. 



Involucre. A whorl or group of bracts surrounding or subtending a single flower, or 



the collection of bracts aggregated at the base of an inflorescence, as the heads 



of Compositae, or in the umbels of Umbelliferae. 

 Involute. A type of vernation, in which the margins are rolled inward or toward the 



upper side. 

 Irregular (flower). See Zygomorphic. 



Keel. A central dorsal ridge like the keel of a boat; the structure formed by the 

 two lower united petals of a papilionaceous flower; the midvein of a compressed 

 floral bract m grasses and sedges. 



LaciNIATE. Cut into narrow pointed lobes. 



Lanceolate. Lance-shaped; much longer than broad, widening above the base, and 



tapering to the apex. 

 Lanceoloid. a solid body lanceolate in longitudinal section. 

 Leaflet. One of the blades of a compound leaf. 

 Legume. The fruit of certain Leguminosae, a pod formed from a simple pistil, and 



dehiscent along both sutures. 

 Lemma. The lower of the two bracts enclosing the flower in grasses. 

 Lenticular. Lentil-shaped, that is, with the shape of a biconvex lens. 

 Ligulate. Provided with or resembling a ligule. 

 Ligule. a thin, often scarious projection from the top of the leaf-sheath in grasses 



and similar plants; the principal part of the corolla of ray-florets in numerous 



Compositae; the membranous structure on the adaxial surface of the leaf of 



Isoeies and Selaginella. 

 Linear. Long and narrow with nearly parallel margins. 

 Lip. Either of the divisions of a bilabiate corolla; the peculiar upper (apparently 



lower) petal in orchids. 

 LocULE. One of the cavities or compartments of a pistil or anther. 

 Lobe. Any part or segment of an organ; specifically, a part of a petal, calyx, or leaf 



that represents a division to about the middle. 

 Loment. a jointed legume, usually constricted between the seeds, and at maturity 



breaking transversely into 1 -seeded, indehiscent segments. 

 Lunate. Crescent- or half-moon-shaped. 

 Lyrate. Lyre-shaped; descriptive of a pinnatifid leaf having a large, rounded terminal 



lobe, and the lateral lobes becoming gradually smaller toward the base. 



Megaspore. The larger of two kinds of spores of a plant, usually giving rise to a 



female gametophyfe. 

 Membranous. Thin, soft, pliable, sometimes more or less translucent. 

 Microspore. The smaller of two kinds of spores of a plant, usually giving rise to a 



male gametophyte. 

 MiCROspoROPllYLL. A sporophyll that bears microspores. 



MoNADELPllOUS. Said of stamens when the filaments are united into one tube. 

 MoNILlFORM. Resembling a string of beads, as the rhizome of certain species of 



5cu/e//ar(a. 

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



