ROSACEA. 4G3 



shrub or small tree, glabrous branching leafless ; branches remote 

 alternate terete striate rather thick, produced into elongated spines, 

 marked with small distant brown scars ; flowers subracemose at ends 

 of twigs ; pedicels spreading curved, articulated below middle." {N'eiv 

 Mexico.) See p. 391. 



VI. PYEE^. 



40. Pyrus T. — Flowers hermaphrodite, more rarely polygamous ; 

 receptacle urceolate, more rarely turbinate, lined by a disk swelling 

 more or less above ovary, ending at a variable distance below 

 stamens. Calyx 5-leaved ; sej)als imbricated in bud, then reflexed, 

 either persistent or deciduous with apex of receptacle. Petals 5, 

 shortly unguiculate ; prsefloration imbricated. Stamens 15-20, more 

 rarely oo (of the Bosace^e) ; filaments free, or shortly connate at base 

 1-adelphous; anthers dehiscing by 2 introrse clefts. Carpels 5, 

 alternipetalous, or 2-4 ; ovaries obliquely inserted within receptacle, 

 free on ventral margin, 1 -celled; styles terminal, all free or more 

 or less connate at base ; apex truncate or capitate, stigmatiferous. 

 Ovules 2 in each cell, collaterally ascending ; micropyle inferior 

 extrorse, often obturated. Fruit ovoidal globular or pyriform, 

 drupaceous ; mesocarp (receptacle) usually thick fleshy ; endocarp 

 1-5-celled, crustaceous or cartilaginous ; often 2-valvate. Seeds J , 2 

 in each cell, erect ; testa usually cartilaginous, slightly muci- 

 laginous ; embryo erect, radicle short inferior ; cotyledons plano- 

 convex fleshy. — Trees or shrubs ; leaves deciduous alternate, simple 

 or pinnate ; stipules 2 lateral deciduous ; flowers corymbose or 

 cymose, often precocious, coming out from rather thick buds before 

 the leaves. [North temperate regions of both JForlds.) See p. 392. 



41. Cydonia T. — Flowers hermaphrodite (nearly of P?/rus) ; re- 

 ceptacle campanulate. Sepals 5, leafy. Petals orbicular, imbricated 

 or rarely contorted in sestivation. Stamens 20- co. Ovary adnate 

 to receptacular cavity, incompletely 5-celled ; cells cleft lengthwise 

 internally, oo-ovulate ; ovules 2-seriate ascending ; styles 5, free. 

 Fruit pomaceous (of Fyrus) crowned by leafy calyx ; endocarp car- 

 tilaginous ; seeds oo in each incomplete cell ; testa crustaceous, 

 thickly mucilaginous outside. — Shrubs or small trees ; leaves alternate 

 (of Pyrus) ; stipules usually leafy ; flowers solitary terminal or few 

 corymbose. [Central Europe, Central and Eastern Asia.) See p. 395. 



