GLOSSARY. 791 



Stipe. The stalk or petiole, as in the fronds of ferns (p. 91) ; also ap- 

 plied to the stalk of mushrooms (p. 57). 



Stipule. A pair of leaf-like structures at the base of some leaves (p. 348). 

 Stolon. See Runner. 

 Stoma (pi. Stomata). A physiological structure developed from the 



epidermal cells and consisting of two guard cells separated by an 



opening. The term is incorrectly applied, by authors, solely to the 



pore or opening between the guard cells. 

 Stones cells (Sclerotic cells). A parenchymatous type of cell, having 



thick, lignified walls (p. 267). 



Strigose (Strigous). Hairs that are straight and sharp pointed or bristle- 

 like ; applied to stems and leaves. 

 Strobile (Strobilus). A cone-like fruit, consisting of bracts and their 



achenes, as in the hop (p. 515). Distinguished from the pine cone 



which contains a pair of seeds at the base of the open scales. 

 Strophiole. A small aril-like appendage, developed at or near the hilum 



of certain seeds, as in Sanguinaria. 



Style. The neck-like portion of the pistil subtending the stigma (p 378). 

 Stylopodium. A disk-like development at the base of the style in the 



fruits of the Umbelliferae. 

 Subulate. Applied to leaves which are narrow, more or less cylindrical 



and tapering to a sharp point, as of some of the junipers. 

 Superior. An ovary which is free from the calyx (p. 78) ; also applied 



to fruits, the pericarp of which has been derived from the walls of the 



ovary only. 



Suture. The line of union of contiguous carpels (p. 377). 

 Symmetrical. Applied to flowers in which the parts of each circle are 



alike in form and number and in which the numerical plan has been 



perfectly carried out (p. 392). 



Sympetalous. Flowers in which the petals are united (pp. 385 and 643). 

 Syncarpous. Applied to a pistil composed of two or more united carpels 



(p. 376). 



Terete. Slenderly cylindrical or slightly tapering, as the stems of bluets. 

 Testa (Episperm). The outer layer of the seed coat (p. 425). 

 Tegmen (Endopleura). The inner layer of the seed coat (p. 425). 

 Tetradynamous. Applied to the stamens of the flowers of the Cruciferae. 



which are 6 in number and occur in 2 sets, one set consisting of 4 



stamens having long filaments, and the other set of 2 stamens having 



short stalks (p. 381). 

 Thallus. The vegetative organ of the Thallophytes. It may consist of 



a single cell, a filament, or a group of cells which gives rise to a more 



or less flattened leaf-like structure (p. 6). 

 Thyrse (Thyrsus). A compact panicle, the flowers of the primary axis 



being of the centripetal class, while the branches are of a centrifugal 



character, as in the lilac. 

 Tomentose (Tomentous). A surface densely covered with matted wooly 



hairs, as of the common mullein (p. 354). 

 Torus. The summit of a stem, forming the receptacle of a flower and 



on which the floral organs are borne (p. 389). 

 Tracheae (Vessels or Ducts). The conducting cells in the woody or xylem / 



portion of the plant. They usually consist of a longitudinal row of 



cells in which the transverse walls are more or less absorbed (p. 273). 

 Tracheids. The characteristic conducting cells comprising the wood or 



xylem of the Coniferae. The cells resemble in form libriform but 



usually are marked by bordered pores (p. 275). 

 Trimorphous. Plants having 3 kinds of flowers, differing in the relative 



lengths of the stamens and style, as in the spiked loose strife (p. 399). 



