Proceedings of the Ohio State Academy of Science. 303 



Rachis — The axis of a compound leaf, spike or raceme. 



Receptacle — The part to which the sporangia are attached. 



Reniform — Kidney-shaped. 



Reticulate — Arranged as a network. 



Revolute — -Rolled backward. 



Rhizoid — The filamentous, root-like outgrowths from the 



thallus of the gametophyte. 

 Rhizome — An underground stem. 

 Rootstock — Same as rhizome. 



Sagittate — Shaped like an arrow-head. 



Sclerenchyma — Bundles of thick walled fibers, in ferns usually^ 



brown or black. 

 Segment — One of the divisions of a pinnatifid or compound leaf.. 

 Serrate — With teeth projecting forward. 

 Sessile — Without a stalk. 



Silex — The silicious coating in the Equisetiuns. 

 Sinuate — With strongly wavy margins. 

 Sinus — The split or space between two lobes. 

 Sorus — A cluster of sporangia in the ferns. 

 Spatulate — Widened at the top like a spatula. 

 Spermatozoid — The male gamete. 

 Spinulose — With small, sharp spines. 



Sporangiophore — A leaf or other organ bearing sporangia. 

 Sporangium — A spore-producing organ. 

 Spore — A modified reproductive cell. 

 Sporocarp — A carpel-like spore-bearing organ. 

 Sporophyll — A spore-bearing leaf. 

 Sporophyte — The nonsexual generation of plants. 

 Stellate — Star-shaped. 

 Sterile — Not producing spores or seeds. 

 Stipe — Sometimes used for the petiole of a fern leaf. 

 Stoma — The transpiring pores in the epidermis of the higher 



plants. (Plural, Stomata.) 

 Subcoriaceous — Somewhat coriaceous. 

 Subulate — ■ Awl-shaped. 



