552 



BULLETIN OF THE BUREAU OF FISHERIES. 



Pyrenoid, a small, definite, rounded, colorless body 

 occurring in a chloroplast and serving as a center 

 of starch accumulation. 



Pyriform, pear shaped. 



Quadrate, four sided, square. 



Racemose, arranged in a cluster of branches along a 

 central axis, the branches becoming of approxi- 

 mately equal lengths and having the older ones 

 below. 



Radial, radiating, as from a center. 



Ramulus (pi., ramuli), a small branch. 



Receptacle, the enlarged fruiting portion of the 

 plant, bearing the sunken cavities (concep- 

 tacles), in the Fucaceae. 



Reticulate, forming a network. 



Rhizoid, a cellular filamentous outgrowth serving 

 as an organ of attachment. 



Rhizoidal, pertaining to rhizoids. 



Rhizome, a creeping portion of a thallus resembling 

 a horizontal stem and giving off upright stem- 

 like or leaflike branches. 



Rimose, having cracks in the surface, as in the old 

 bark of trees. 



Rotund, rounded in outline, but a little inclined 

 toward oblong. 



Scutellate, shaped like a small platter. 



Secund, bearing branches or organs on only one 

 side of an axis. 



Septate, bearing septa. 



Septum (pi., septa), a partition. 



Seriate, arranged in series or rows. 



Serrate, bearing numerous short, sharp, marginal 

 teeth, like those of a saw. 



Serration, the bearing of serrate teeth. 



Sessile, borne directly on the axis, not on a stalk. 



Setaceous, very slender and rigid, bristlelike. 



Silique, the peculiar pod of the mustard family. 



Sinus, the more or less acute angle formed by the 

 division of a thallus into approximately equal 

 parts. 



Sorus (pi., sori), a definite cluster of reproductive 

 organs. 



Spatulate, oblong, with the basal end attenuated, 

 like a spatula. 



Spermatangium (pi., spermatangia) , a more or less 

 specialized organ bearing male cells. 



Spermatium (pi., spermatia), a nonmotile male cell, 

 occurring in the Rhodophyceae. 



Sporangiferous, bearing sporangia. 



Sporangium (pi., sporangia), a specialized organ 

 bearing spores formed nonsexually. 



Spore, a cell specialized for propagation and cap- 

 able, without fusion with any other cell, of grow- 

 ing into a new plant. 



Sporocarp, a fruit produced as a result of the fer- 

 tilization of the egg in the carpogonium, includ- 

 ing the carpospores and the accessory structures, 

 occurring in the Florideae. 



Stellate, star shaped. 



Stichidium (pi., stichidia), a specialized branch 

 bearing tetrasporangia, occurring in a few Flor- 

 ideae. 



Stipe, the narrow, stemlike stalk by which a flat- 

 tened thallus is attached. 



Stipitate, possessing a stipe. 



Stolon, a horizontal, stemlike portion which, at- 

 taching itself and becoming separate from the 

 parent, forms a new plant. 



Sub-, used as a prefix to denote somewhat, to a 

 limited degree, as subacute; used as a prefix to 

 denote under, as subcortex. 



Substratum, the underlying substance on which a 

 plant is growing. 



Subulate, subuliform, awl shaped, long, slender, 

 and pointed. 



Sympodial, having an arrangement where each 

 branch forms a part of the main axis, the result- 

 ing axis thus being formed partly from the 

 branches, but resembling a simple axis. 



Synonym, an incorrect name used for a species 

 which has a correct name. 



Taxonomic, referring to the classification of plants 

 according to their relationships. 



Terete, cylindrical and usually tapering, circular 

 in cross section. 



Tetrahedral, four sided, used especially with refer- 

 ence to apical cells, and sometimes to tetra- 

 sporangia which are triangularly divided. 



Tetrasproangium (pi., tetrasporangia), a sporan- 

 gium whose contents are divided into four spores, 

 occurring in the Floridese and the Dictyotaceae. 



Tetraspore, one of the four spores formed in a tetra- 

 sporangium. 



Tetrasporic, bearing tetraspores, frequently used 

 with the same meaning as asexual. 



Thallus, a plant body not distinctly differentiated 

 into stem and leaf. 



Tortuous, bent or twisted in different directions. 



Torulose, cylindrical, with swollen portions at in- 

 tervals, somewhat moniliform. 



Triangular, a method of division of a tetrasporan- 

 gium by four walls formed in different planes and 

 meeting at the center, three of the resulting 

 tetraspores usually being visible on a single 

 surface, each appearing triangular in shape. 



Trichoblast, a filamentous, lateral outgrowth con- 

 sisting of a single row of cells, usually much 

 branched, borne on the surface of a thallus. 



