QUAKE-GRASS 551 



Pyrene, a single stone of a drupe. 



Pyrethrurn Hall. = Chrysanthemum Tourn. (Comp.). 



Pyriform, pear-shaped. 



Pyrola (Tourn.) L. (incl. Moneses Salisb.). Pyrolaceae. i=. N. temp. 

 (5 Brit., wintergreen). Evergreens with creeping stocks. P. (Moneses) 

 itniftora L. has adv. buds on the roots, and a solitary term. fl. The 

 fls. of 'P. minor L. are in racemes, pend., without discs. There is no 

 honey ; the stigma projects beyond the anthers, but pollen may at last 

 fall upon it from them. P.-rotundifolia L. is similar. The seeds of 

 P. are very light and are distr. by wind. 



Pyrolaceae (EP.; Ericaceae p. p. , Monotropeae BH.}. Dicots. (Sympet. 

 Ericales). 10 gen., 30 sp., cold N. temp, and arctic. The two Brit, 

 genera represent the two types of habit found in the order evergreen 

 plants with sympodial growth from rhiz. (Pyrola), and saprophytes 

 (Monotropa). The infl. is term.; it may be a true raceme (Pyrola), 

 or a cyme, leafless or with scaly bracts. Fl. 5 actinom. K 4 5 ; 

 C (4 5) or 4 5; A 8 10, obdiplost. ; G (4 =,). The petals and 

 sta. are often at the edge of a nectariferous disc. Anthers intr., 

 opening by apical pores or transv. valves; pollen simple or in tetrads. 

 Cpls. opp. petals; ovary imperfectly 4 5-loc. Style simple; ovules 

 minute, oo , anatr. , on thick fleshy plac. Capsule. Seeds oo , small, 

 in loose testa. Embryo of few cells, without differentiation of cotyle- 

 dons. Chief genera : Pyrola, Chimaphila, Monotropa, Sarcodes. 

 BH. unite Pyrola and the green-leaved forms to Ericaceae, making a 

 fam. Monotropeae for the saprophytes. 



Pyronia x Veitch. Rosaceae. Hybrid, Pyrus-Cydonia (pear and quince). 

 See_/0;'M. of Hered. 1916, p. 416. 



Pyrostegia C. Presl (Bignonia p.p. BH.}. Bignon. (i). 10 S. Am. 



Pyrostria Comm. ex Juss. Rubiaceae (ll. i). 8 Mauritius, Rodrigues. 



Pyrrhopappus DC. (Sitilias Rafin.). Compositae (13). 6 N. Am. 



Pyrrocoma Hook. (Aplopappus Cass.). Compositae (3). 20 N. Am. 



Pyrularia Michx. Santalaceae. 2 N. Am., Himalaya. 



Pyrus (Tourn.) L. (BH. incl. Cydonia, Mespilus}. Rosaceae (n). 65 

 N. temp.; 6 in Brit., incl. P. Aitcnparia Ehrh., the rowan or mountain 

 ash, P. Alalus L. the apple, &c. The recept is hollowed out and 

 united to the syncarpous ovary. The fls. are protogynous. and are 

 visited by bees and many other insects. Several var. of pear (P. 

 cominunis L.) are self-sterile. After fert. the fr. becomes a large fleshy 

 pseudocarp (pome), the flesh consisting of the enlarged recept., while 

 the gynaeceum forms the core. Several are cultivated for their fruit, 

 e.g: P. Mat 'us L. (apple), P. cominunis L. (pear), P. germanica Hook, 

 f. (medlar). P. japonica Thunb. is often grown upon walls. 



Pyxidantliera Michx. Diapensiaceae. i E. U.S. 



Pyxidanthus Naud. (Blakea BH.}. Melastomaceae (i). 3 N. trop. 

 S. Am. 



Pyxis, capsule opening by a lid that splits off, Anagallis. 



Quadrania Nor. Inc. sed. Nomen. 



Quadrasia Elmer. Flacourtiaceae (4). i Phil. Is. 



Quadri- (Lat. pref.), four. 



Quaternate, arranged in fours. 



Quake-grass, Briza. 



