_Tubercle_, a small wart-like excrescence. _Tubular_, hollow and cylindrical. _Turbinate_, top-shaped. _Typical_, agreeing closely with the characters assigned to a group or species. _Umbilicate_, having a central depression. _Umbo_, the boss of a shield; applied to the central elevation of the cap of some mushrooms. _Umbonate_, having a central boss-like elevation. _Uncinate_, hooked. _Unequal_, short imperfect gills interspersed among the others. _Universal_, used in relation to the veil or volva which entirely envelops the mushroom when young. _Variety_, an individual of a species differing from the rest in external form, size, color, and other secondary features, without perpetuating these differences only under exceptional circumstances. _Veil_, in mushrooms a partial covering of the stem or margin of the pileus. _Veliform_, a thin veil-like covering. _Venate_, _Veined_, intersected by swollen wrinkles below and on the sides. _Ventricose_, swollen in the middle. _Vernicose_, shining as if varnished. _Verrucae_, warts or glandular elevations. _Verrucose_, covered with warts. _Villose_, _villous_, covered with long, weak hairs. _Virescent_, greenish. _Virgate_, streaked. _Viscid_, covered with a shiny liquid which adheres to the fingers when touched. _Viscous_, gluey. _Volute_, rolled up in any direction. _Volva_, a substance covering the mushroom, sometimes membranous, sometimes gelatinous; the universal veil. _Walnut brown_, a deep brown like that of some varieties of wood. (Raw umber, and burnt sienna and white.) _Wart_, an excrescence found on the cap of some mushrooms; the remains of the volva in form of irregular or polygonal excrescences, more or less adherent, numerous, and persistent. _Zone_, a broad band encircling a mushroom. _Zoned_, furnished with one or more concentric circles. Although some writers apply the terms spore, sporidia, sporophore, sporules, and conidia somewhat indiscriminately to all spore bodies, in order to avoid confusion, it is now recommended by the best authorities that certain distinctive limitations should be adhered to in the use of these terms. Saccardo, in defining the terms which he employs, accepts the term spores as applicable exclusively to the naked spores supported on basidia, as found in the Basidiomyceteae. The term sporidia he limits to spores produced or enclosed in an ascus, as in the Ascomyceteae. The term sporules he applies to the spores of imperfect fungi, where they are enclosed in perithecia (microscopic cups or cells), such as the Sphaeropsidea. The term conidia he uses to designate the spores of imperfect fungi without perithecia or asci, such as the Hyphomyceteae and the Melanconieae. This arrangement is in accordance with M. C. Cooke's published views on the subject, except in the case of the spore bodies of the Melanconieae, which he prefers, for well-defined reasons, to call sporules.