GLOSSARY. 



92S 



Sub-capitulum, a secondary capitulum. 



Suberin, a corky substance ; the substance or group 

 of suljstances present in cuticularized or corky cell- 

 walls. 



Subex, a stem bearing scale-leaves. 



Succulent, fleshy, pulpy. 



Sucker. See Surculus. 



Suffrutex, an under-shrub; a woody jolant of quite 

 humble growth. 



Suffruticose, somewhat shrubby. 



Surculus, or Sucker, a shoot arising from a sub- 

 terranean base. 



Suspensor, in Flowering Plants and in Selaginella ; 

 the filament of cells at the lower extremity of which 

 the embryo arises. 



Suture, a line of union, very frequently the line along 

 which dehiscence also takes jjlace. 



Swarm, a social aggregate of simple organisms which 

 live together but are not attached to any substratum. 



Swarm-spore, a motile, ciliated, asexual reproductive 



cell destitute of a cell-membrane. 

 Switch-plant, a jilant with reduced or wanting 



leaves, the shoots of which are green and subserve 



the functions of leaves. 

 Symbiosis, the association of two organisms which 



live together in intimate connection, both contri- 

 buting to their mutual welfare. 

 Syncarpous, said when the carpels of a gynoeceum 



are united. 

 Synconium, the fleshy excavated inflorescence of a 



Fig. 

 Synergidae, two naked cells situated at the micro- 



pylar end of the embryo-sac, and as.sisting in the 



passage of the male cell to the egg in porogamic 



fertilization. 

 Syngenesia, the 19th class of the Linnean system. 

 Syngenesious, having coherent anthers. 

 Systole, the rhythmic contraction of a contractile 



vacuole. 



Tagmata, aggregates of micellae. 



Tapetal cells, the layer of cells immediately external 



to the archesporium, and becoming latterly dis- 

 organized with the maturing of the spores (or 



pollen-grains). 

 Teleutospore, in Uredinese, a resting-spore which on 



germinating gives rise to a pro-mycehum or basi- 



dium. 

 Tenaculum, the clasj^ing, rosette-like clamps of 



Struvea, by means of which independent branches 



are held together. 

 Tendril, a filamentous branched or unbranched organ, 



usually sensitive to contact, by means of which a 



plant climbs. 

 Tentacle, an irritable hair or emergence on a leaf, 



as in Dionsea, Drosera, &c. 

 Terete, round, i.e. circular in transverse section. 

 Ternary hybrid, the plant resulting from crossing a 



hybrid with a species different from either of its 



parent forms. 

 Ternate, used of compound leaves with three leaflets, 



one terminal and two lateral. 

 Testa, the integument of a seed, often arising from 



the outer of the two ovular coats. 

 Tetrad, a group of four cells (e.g. spores, pollen-grains), 



usually arranged in the foiir corners of a 4-sided 



pyramid (tetrahedon). 



Tetradynamia, the 15th class of the Linnean sys- 

 tem. 



Tetradynamous, used of stamens when there are 

 six, of which four are longer than the other two — 

 as in Cruciferas. 



Tetraspores, the asexual spores of Red Sea-weeds, 

 usually aggregated in clusters of four. 



Thalamus, the floral receptacle. 



Thallidium, a vegetative reproductive body, espe- 

 cially amongst Thallophytes and Muscinese. 



Thallus, a vegetative body without differentiation 

 into stem and leaf. 



Thermal constants of vegetation. See vol. i, 

 p. 557. 



Tissue, a continuous aggregate of cells having a 

 common origin. 



Tomentose, felty or invested in tomentum. 



Tomentum, dense matted investment of woolly 

 hairs. 



Torus, (1) the floral recejjtacle ; (2) the thickening 

 on the jiit-closing membrane of a bordered pit. 



Trabeculae, folds or ridges projecting into a cell from 

 the wall; the term also given to strings of fila- 

 mentous cells bridging intercellular spaces. 



Tracheids, elongated, poiated, and more or less 

 lignified cells occurring in wood. 



Transpiration, the act of exhaling aqueous vapour 

 from foliage or other portions of jjlants. 



Trichoblasts, fusiform hard-walled cells. Not a 

 good term. 



Trichogyne, the filamentous portion of the female 

 sexual apparatus of a Red Sea-weed, which receives 

 the spermatia. 



Trichome, a hair-like or similar outgrowth of the 

 epidermis. 



Truncate, appearing as if cut short at the tip. 



Trunk, a main stem. 



Tuber, a subterranean, somewhat fleshy shoot. 



Tubercle, a small excrescence. 



Tumescent, becoming enlarged, distended. 



Turgescence, Turgidity, the state of tension set 

 up \\-ithin a cell owing to the jjressure of the osmo- 

 tic cell-contents upon the elastic cell-wall. 



Turion, a subterranean budding shoot, especially in 

 jjerennials. 



Umbel, an inflorescence in which a cluster of flower- 

 stalks arises all from the same point. 



Unguiculate, narrowed at the base into a claw: 

 used of petals. 



Urceolate, hollow and contracted at or below the 

 mouth hke an urn. 



Uredospore. See vol. ii. p. 686. 



Utricle, an archaic term for a jjarenchyma-cell. 



Vacuole, a cavity in the protoplasm containing cell- 

 sap. 



Vagina, the sheathing portion of a leaf-base. 



Valvate, having valves ; opening by valves ; also, 

 used of the arrangement of the parts of a flower- 

 bud when they just meet but do not overlap. Cf. 

 vol. ii. p. 210. 



Valve, (1) in flowering plants, the pieces into which 

 a capsule breaks are termed valves ; also the mov- 

 able flaps in the dehiscence of anthers ; (2) in Dia- 

 toms, the valves are the halves of the süicified 

 membrane or shell, also called frustules. 



