GONIDIA, green cells in the thallus of lichens. GRAIN, caryopsis, the fruit of grasses. GRUMOUS, collected into granular masses. GYMNOGEN, a plant with naked seeds, _i. e._, seed not in a true ovary. GYMNOSPERMOUS, plants with naked seeds, _i. e._, seeds not in a true ovary; such as conifers. GYNANDROUS, stamen and pistil united in a common column, as in the _Orchidaceæ_. GYNOBASE, a central axis, to the base of which the carpels are attached. GYNŒCIUM, the female organs of the flower. GYNOPHORE, a stalk supporting the ovary. GYRATE, same as circinate. H HABIT, general external appearance. HASTATE, halbert-shaped, applied to a leaf with two portions at the base projecting more or less completely at right angles to the blade. HAULM, dead stems of herbs, as of the potato. HAUSTORIUM, the sucker at the extremity of the parasitic root of dodder. HEART-WOOD, same as Duramen. HELICOIDAL, having a coiled appearance like the shell of a snail; applied to inflorescence. HERB, a plant with an annual stem, opposed to a woody plant. HERBACEOUS, green succulent plants which die down to the ground in winter; annual shoots, with green-colored cellular parts. HERMAPHRODITE, stamens and pistils in the same flower. HESPERIDIUM, the fruit of the orange and other _Aurantiaceæ_. HETEROCYSTS, peculiar large cells in _Nostochineæ_. HETEROGAMOUS, composite plants having hermaphrodite and unisexual flowers on the same head. HETEROPHYLLOUS, presenting two different forms of leaves. HILUM, the base of the seed to which the placenta is attached either directly or by means of a cord. The term is also applied to the mark at one end of some grains of starch. HIRSUTE, covered with long stiff hairs. HISPID, covered with long, very stiff hairs. HISTOLOGY, the study of microscopic tissues. HOMOGENEOUS, having a uniform structure or substance. HYALINE, transparent or colorless. HYBRID, a plant resulting from the fecundation of one species by another. HYMENIUM, the part which bears the spores in Agarics. HYPANTHODIUM, the receptacle of _Dorstenia_, bearing many flowers. HYPOCHILUM, the lower part of the labellum of orchids. HYPOCRATERIFORM, shaped like a salver, as the corolla of _Primula_. HYPOGEOUS, under the surface of the soil; applied to cotyledons. HYPOGYNOUS, inserted below the ovary or pistil. I IMBRICATE, parts overlying each other like tiles on a house. _Imbricated æstivation_, the parts of the flower-bud alternately overlapping each other, and arranged in a spiral manner. IMPARI-PINNATE, unequally pinnate; pinnate leaf ending in an odd leaflet. INARCHING, a mode of grafting by bending two growing plants toward each other, and causing a branch of the one to unite to the other. INARTICULATE, without joints or interruption to continuity. INCISED, cut down deeply.