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 Ec[uisetums, 



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-lik'e 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. 



