GLOSSARY 247 



Host. A plant or animal ■which nourishes a parasite. 



Hybrid (a mongrel). The oflspring obtained by the action of the pollen 

 of one species on the pistil of another. The term is also used for 

 the offspring of any cross. 



Hydrophyte (water plant). A water plant. 



Hygroscopic (moisture seeing). Expanding or shrinking readily under 

 the influence of moisture. 



Hymenium (a membrane). An expanded fruiting surface of a fungus. 



Syphai, plu. hyphm (a web). The filament of a fungus. 



Hypocotyl. The portion of an embryo or very young seedling between 

 the cotyledons and the root. 



Hypogynous. A term applied to flowers in which the stamens and peri- 

 anth gi'ow from beneath the ovary. 



Indeterminate. A term applied to stems where the growth in length is 



indefinite because no terminal bud is formed, and to an inflorescence 



where there is no terminal flower. 

 Indusium. In ferns a protective outgrowth from the leaf covering a 



cluster of sporangia or soi-us. 

 Inferior ovary. See Epigynous. 

 Inflorescence (flowering). The manner in which the flowers are arranged 



in the flower cluster. 

 Intercellular. Between the cells or among them. 

 Internode. The portion of the stem between two nodes. 

 Involucre (a wrapper). A ring of bracts surrounding, several flowers or 



their flower stalks. 

 Irritability (easily excited). Sensitiveness to stimuli, such as light, heat, 



gravity, etc. 

 Isogamy (equal gametes). The condition where the pairing gametes are 



similar in form and structure. 



Lamina, plu. laminm (a layer). The blade of a leaf. 



Leaf trace. The group of nbro-vascular, bundles which connects the 

 veins of the leaf with the fi^bro-vascular system of the stem. 



Lenticel. A roundish or lens-shaped spot on young bark, marking the 

 former position of a stoma. 



Leptosporangiate. A term applied to pteridophytes in which the sporan- 

 gium arises from a single epidermal cell. 



Leucoplast (white molded). A protoplasmic body found in cells in the 

 interior of the plant body, often serving as a starch builder, — a 

 colorless plastid. 



Lignin (wood). The thickening material deposited in cell walls to pro- 

 duce woody tissue. 



Locule (a little compartment). A cavity or chamber, as of an ovary. 



Medullary (belonging to the marrow). Related to the pith, as the med- 

 ullary rays. 



