_Determinate_, ending definitely; having a distinctly defined outline. _Diaphanous_, transparent. _Dichotomous_, paired by twos; regularly forked. _Dimidiate_, applied to some gills of mushrooms which reach only halfway to the stem. _Disciform_, of a circular, flat form. _Dissepiments_, dividing walls. _Distant_, applied to gills which have a wide distance between them. _Divaricate_, separating at an obtuse angle. _Echinate_, furnished with stiff bristles. _Echinulate_, with minute bristles. _Effused_, spread over without regular form. _Elongate_, lengthened. _Emarginate_, applied to gills which are notched or scooped out suddenly before they reach the stem. _Embryo_, the mushroom before leaving its volva or egg stage; also any early stage of mushrooms which may have no volva. _Entire_, the edge quite devoid of serrature or notch. _Epidermis_, the external or outer layer of the plant. _Epiphytal_, growing upon another plant. _Equal_, all gills of the same, or nearly the same length from back to front. _Eroded_, the edge ragged, as if torn. _Etiolated_, whitened, bleached. _Even_, distinguished from smooth: a surface quite plane as contrasted with one which is striate, pitted, etc. _Excentric_, out of center. The stems of some mushrooms are always excentric. _Exotic_, foreign. _Family_, a systematic group in scientific classification embracing a greater or less number of genera which agree in certain characters not shared by others of the same order. _Farinaceous_, mealy. _Farinose_, covered with a white, mealy powder. _Fascia_, a band or bar. _Fasciate_, zoned with bands. _Fasciculate_, growing in small bundles. _Fastigiate_, bundled together like a sheath. _Favose_, honeycombed. _Ferruginous_, rust-colored. _Fibrillose_, clothed with small fibers. _Fibrous_, composed of fibers. _Filiform_, thread-like. _Fimbriated_, fringed. _Fissile_, capable of being split. _Fistular_, _fistulose_, tubular. _Flabelliform_, fan-shaped. _Flavescent_, yellowish, or turning yellow. _Flexuose_, wavy. _Flocci_, threads as of mold. _Floccose_, downy. _Flocculose_, covered with flocci. _Foveolate_, pitted. _Free_, in relation to the gills of mushrooms reaching the stem but not attached to it. _Fringe_, a lacerated marginal membrane. _Fructification_, reproducing power of a plant. _Fugacious_, disappearing rapidly. _Furcate_, forked. _Fuliginous_, blackish or sooty. _Fulvous_, tawny; a rather indefinite brownish yellow. _Furfuraceous_, with branny scales or scurf. _Fuscous_, brownish, but dingy; not pure. _Fusiform_, spindle-shaped. _Genera_, plural of genus. _Generic_, pertaining to a genus. _Genus_, a group of species having one or more characteristics in common; the union of several genera presenting the same features constitutes a tribe. _Gibbous_, in the form of a swelling; of a pileus which is more convex or tumid on one side than the other.