XXII 



GLOSSARY. 



Proliferation or prolification. — An extension, in the same or 

 another form, of the organ or of subsidiary parts of it. 



Prothallus. — The non-vascular individual of the sexual gene- 

 ration in vascnlar Cryptogams and Gymnosperms. 



Protonema. — The green filament, belonging to the sexual 

 generation, which results from the germination of a 

 spore in mosses. 



Pseudo-bulb.- — An aerial tuberous shoot borne by epiphytic 

 orchids. 



Pseudo- -stipules. — The basal segments of a leaf (as in Crataegus) 

 which have been derived from the lamina and not from 

 the leaf-sheath. 



Rachis. — The central axis of an inflorescence or leaf. 



Radicle. — The root of the embryo and seedling. 



Ramenta. — Membranous, scale-leaf-like outgrowths occurring 

 on the petioles and shoots of some plants, e. g. ferns. 



Rejuvenescence. — The return to a youthful or ancestral con- 

 dition. 



Reversion. — A return to an older, ancestral condition. 

 Rhizogenous. — Root-producing. 



Rhizoid. — The colourless modification of the protonemal 

 filament in Bryophytes serving to attach the plant to the 

 substratum ; in Fungi the mycelial threads which serve 

 the same purpose. In both cases the rhizoid may be 

 regarded as a " root." 



Rhizophore. — A highly modified, leafless, downward-growing 

 shoot, producing adventitious roots near its tip; it occurs 

 in the Lycopodiales. 



Ring or Annulus. — The lower part of the ruptured veil, 

 forming a frill upon the stipe, in Fungi. 



Ring -fasciation. — A stem-structure, resulting either from 

 dichotomy or fusion, in which the tissues are composed 

 of two concentrically-arranged sets ; an external, nor- 

 mally orientated, and an internal, inversely orientated one. 



Rudimentary . — Not having a full and complete development. 



Sarcody. — The change to a fleshy consistence. 



Scale-leaf. — A scarious or fleshy foliar organ, devoid of 

 chlorophyll, situated on the vegetative axis. 



Scape. — A completely or almost leafless peduncle, springing 

 from the centre of a rosette of foliage-leaves and bear- 

 ing a single terminal flower or capitulum. 



Schizocotyly. — The forking and multiplication of cotyledons. 



Sclerotium. — The compact resting-mass of fungal hyphae. 



Sepalody. — The change into a sepal. 



Seta. — The stalk bearing the capsule in the sporogonium. 



