GLOSSARY 439 



Tu'berous. Bearing or resembling tubers. 



Tu'nicated. Covered with successively overlapping coats as the bulb of an 



Onion. 



Tur'binate. Top-shaped. 

 Turges'cent. Swelling. 

 Tylo'sis. A protrusion of the wall of a cell through the pit in the wall of an 



adjacent vessel and appearing in the cavity of the latter. 

 Type. An individual possessing the essential characteristics of the group to 



which it belongs. 



Um'bel. The typical inflorescence of the family Umbelliferae. A more or 

 less flat topped indeterminate inflorescence in which the pedicels spread 

 like the stays of an umbrella. 



Un'ciform. Hook-shaped. 



Un'dershrub. A low shrub-like plant whose base is woody and upper portion 

 herbaceous. 



Un'dulate. Having a wavy margin. 



Uni. A prefix of Latin origin meaning one. 



Unilateral. One-sided. 



Uniloc'ular. One-celled. 



Unise'riate. Arranged in a single row, as the cells of some plant hairs. 



Ur'ceolate. Urn-shaped. 



Ure'dospore. A one-celled spore produced during the life history of a Rust. 



U'tricle. An akene with a bladdery pericarp as Chenopodium fruit. 



Vacuole. A cavity within the protoplasm of a cell usually containing cell sap. 

 Valv'ate. Applied to the leaves of a flower in the bud stage when their margins 



meet but do not overlap. 

 Valve. One of the halves of a diatom. One of the parts of a pericarp that 



splits open when ripe. 

 Variety. A sub-species. 



Vas'culum. A collecting case used by botanists. 

 Veg'etable. A plant. 



Vein. A strand of fibrovascular tissue in a leaf. 

 Vala'men. An absorptive tissue composed of several layers of dead cells 



covering the roots of some tropical epiphytic orchids and aroids. 

 Vena'tion. The arrangement of veins in a leaf. 

 Ven'ter. The enlarged basal portion of an archegonium. 

 Ven'tral Canal' Cell. A cell beneath the entrance of the neck portion of an 



archegonium. 



Vermic'ular. Worm-shaped . 



Verna'tion. The manner in which leaves are disposed in the bud. 

 . Ver'rucose. Wart-like. 

 Verticillas'ter. A pair of dense cymes in the axils of opposite leaves. 



