108 PBACTICAL BOTANY. 



PcBERULENT : clothed with almost imperceptible down. 

 PcBESCENT : hairy or downy. 



Pyxis : a pod (sometimes membranaceous) opening by a circum- 

 soissile — namely, horizontal — circular line. 



Quadrangular : four-angled. 



QuiNCUNOiAL ^STIYATION : tliat variety of imbricated aestivation in 

 which 2 of 5 leaves of a floral circle are wholly without, 2 wholly 

 within, and one, one margin out, the other within. 



Raceme: a sort of centripetal inflorescence, a flower-cluster with 

 pedicelled flowers, arranged along the sidi;s of the axis of inflo- 

 rescence. 



Racemed, Racemose : arranged in a raceme. 



Radiant: outer flowers enlarged, and often neutral, as in Hydran- 

 gea, or in Viburnum Opulus, or the same as radiate. 



Radiate elowurs : ray-flowers, the ligulate flowers of Composites in 

 the margin of each head. 



Radical : proceeding from the root ; radical leaves : root-leaves. 



Radicle : the stem-part of the embryo. 



Ramose : branching. 



Ray : a ligulate marginal flower in a head. 



Receptacle : 1, the summit of the peduncle or pedicel, into which 

 the parts of a single flower are inserted ; 3, an expansion of the 

 top of the stalk, which bears a flower-head (in the Composites, etc.). 



Reduplicate (in sestivation) : valvate with the margins turned out- 

 ward. 



Replexed : bent outward and backward. 



Rbgulab : with the parts similar. 



Reniform : kidney-shaped. 



Repand : wavy-margined. 



Reticulated : with a network of veins. 



Revolute: rolled backward. 



Rhachis : the axis of a spike. 



Rhizome : a root-stock. 



RiNGENT : gaping open ; a term applied to some 2-lipped corollas. 



Root-stock : a root-like portion of the stem under ground, usually 



horizontal, as in Polygonatum. 

 Rosette : a cluster of leaves at about the same height of the axis, 



usually near the ground, directed to all sides, and almost whorled. 

 Rostrate : furnished with a beak. 

 Rotate: wheel-shaped. 

 Rudimentary : poorly, imperfectly, or not yet properly developed. 



