990 MISC. PUBLICATION 200, U. S. DEPT. OF AGRICULTURE 



Gregarious. Growing in groups or masses. 



Herbaceous. Having the characters of an herb; opposed to woody; thin in texture 



and green in color, as the herbaceous lemmas of Poa. 

 Hirsute. Pubescent with straight rather stiff hairs. Hirsutulous, hirtellous. 



Minutely hirsute. 

 Hispid. Pubescent with stiff or rigid hairs. Hispidulous. Diminutive of 



hispid. 

 Hyaline. Thin and translucent or transparent. 

 Imbricate. Overlapping, as the lemmas in many spikelets. 

 Implicate. Tangled, as the branches of the panicle of Panicum implicatum. 

 Indurate. Hard. Compare chartaceous and coriaceous. 

 Inflated. Puffed up, bladdery. 

 Inflexed. Turned in at the margins. Said especially of the margin of the glumes 



or lemmas in some species. 

 Inflorescence. The flowering part of a plant. 

 Innovation. The basal shoot of a perennial grass. 



Internerves. The spaces between the nerves. Said of glumes and lemmas. 

 Internode. The part of a stem between two successive nodes. 

 Interrupted. The continuity broken. Said especially of dense inflorescences 



whose continuity is broken by gaps. 

 Involucre. A circle of bracts below a flower or flower cluster. In grasses applied 



to the cluster of bristles or sterile branchlets below the spikelets in Pennisetum 



and a few other genera, and to the bony bead of Coix. 

 Involute. Rolled inward from the edges, the upper surface within. Said of 



blades. 

 Joint. The node of a grass culm. The internode of an articulate rachis. 

 Keel. The sharp fold at the back of a compressed sheath, blade, glume, or lemma. 



The palea and sometimes the glumes and lemmas may be two-keeled. Keel 



is used because of the similarity to the keel of a boat. 

 Lacerate. Torn at the edge or irregularly cleft, as in some ligules. 

 Lanate. Woolly, clothed with long tangled hairs. 

 Lanceolate. Rather narrow (surface) tapering to both ends, the broadest part 



below the middle. 

 Laterally (compressed). Flattened from the sides, as certain spikelets, glumes, 



and lemmas. 

 Lax. Loose. Said of a soft or open inflorescence and of soft or drooping foliage. 

 Leaf. The lateral organ of a stem, in grasses consisting of sheath and blade. 

 Lemma. The bract of a spikelet above the pair of glumes. 

 Ligule. The thin appendage on the inside of a leaf at the junction of sheath and 



blade. 

 Linear. Long and narrow with parallel sides. Said of surfaces, such as a blade. 



Said also of spikelets and other organs, having in mind the shape of a longi- 

 tudinal section. 

 Lobe. A segment of an organ, usually rounded or obtuse. Applied especially 



to the divisions of a cleft lemma. 

 Loose. Open. Said of panicles. The opposite of dense or compact. 

 Membranaceous. Thin like a membrane. 

 Monoecious. Unisexual, the two kinds of flowers on the same plant, as in Zca 



and Zizania. 

 Mucro. A minute awn or excurrent midnerve of an organ. Mucronate. Pro- 

 vided with a mucro. 

 Navicidar. Boat-shaped. Shaped like the bow of a canoe. Applied especially 



to the tip of blades. 

 Nerve. The vascular veins (mostly longitudinal) of the blades, glumes, and 



lemmas. 

 Neuter. Without stamens or pistils. Said of florets or spikelets. 

 Nodding. Inclined somewhat from the vertical. Said of panicles. 

 Node. The joint of a culm. 

 Ob-. A prefix meaning inversely, as obovate. 

 Oblong. Longer than wide, with parallel sides, but not so long as linear. Applied 



also to panicles and other parts, having in mind a longitudinal section. 

 Obsolete. Almost wanting. Applied to organs usually present. 

 Obtuse. Rounded at the apex. Contrasted with acute. 

 Open. Loose. Said of panicles. Opposite of dense or compact. 

 Oval. Broadly elliptic. 



Ovate. The shape of the longitudinal section of an egg, broadest below the middle. 

 Ovoid. An egg-shaped solid. 

 Palea. The inner bract of a floret. 



