PEACH FAMILY 465 



17. Rosa gymnocarpa Nutt. Wood Rose. Fig. 2518. 



Rosa gymnocarpa Nutt. ex Torr. & Gray, Fl. N. Amer. 1 : 461. 1840. 



Stems slender, erect, 1-3 m. high, often very bristly and with slender infrastipular prickles, 

 the floral branches often unarmed. Stipules narrow, glandular-ciliate and usually dentate; 

 petioles and rachis usually glandular-hispid ; leaflets 5-9, suborbicular to elliptic, 1-3 cm. long, 

 thin, glabrous on both surfaces, doubly serrate with gland-tipped teeth ; flowers usually solitary ; 

 hypanthium ellipsoid, in fruit 4-6 mm. broad; sepals ovate, acuminate, glabrous on the back, 

 deciduous with the styles. 



In shady woods, chiefly Humid Transition Zone; British Columbia to Montana and central California. Type 

 locality: in shady woods, Oregon. May-July. Bald-hip Rose. 



Greene (Leaflets Bot. Obs. 2: 255-266. 1912) has described ten segregates of this species based on minor 

 vegetative variations. 



18. Rosa Bridgesii Crepin. Bridges' Rose. Fig. 2519. 



Rosa Bridgesii Crepin, Bull. Soc. Bot. Belg. 15: 54. 1876. 



Rosa gymnocarpa var. pubescent S. Wats. Bot. Calif. 1: 187. 1876. 



Rosa crenulata Greene, Leaflets Bot. Obs. 2: 255. 1912. 



Rosa oligocarpa Rydb. N. Amer. Fl. 22: 532. 1918. 



Stems slender, low and spreading, 2-10 dm. high, armed with straight or slightly curved 

 infrastipular prickles, the floral branches often unarmed. Stipules glandular-ciliate; petioles 

 and rachis puberulent and glandular ; leaflets suborbicular to oval, 1-2 cm. long, doubly serrate 

 with gland-tipped teeth, finely pubescent on both surfaces; flowers mostly solitary; pedicels 

 glabrous or somewhat glandular-hispid ; hypanthium glabrous, globose, 6-7 mm. broad in fruit ; 

 sepals ovate, acuminate, about 8 mm. long, deciduous with the styles. 



Open pine forests, Arid Transition Zone; southern Oregon to the southern Sierra Nevada, California. Type 

 locality: California. June-July. 



Family 65. AMYGDAL-ACEAE. 

 Peach Family. 



Trees or shrubs, the bark exuding gum, and the leaves, bark, and seeds contain- 

 ing prussic acid and bitter. Leaves alternate, simple, petioled, serrate or entire, the 

 teeth and petioles often glandular, the stipules small, early deciduous. Flowers in 

 terminal or axillary racemes or corymbs, or sometimes solitary, regular and usually 

 perfect. Hypanthium campanulate or turbinate, free from the ovary, deciduous. 

 Sepals and petals 5, inserted on the rim of the hypanthium. Stamens 10-25, in- 

 serted with the petals. Pistils 1 or in one genus 5 ; ovary 1-celled ; ovules 2, pendu- 

 lous ; fruit a more or less fleshy drupe with a bony stone ; seeds 1 or rarely 2. 



About 6 genera and 120 species, widely distributed, most abundant in the northern hemisphere. 

 Pistil 1; flowers perfect; leaves serrate. *• Prunus. 



Pistils usually 5; flowers polygamo-dioecious; leaves entire. 2. Osmaronia. 



1. PRUNUS [Tourn.] L. Sp. PI. 473. 1753. 

 Trees or shrubs, with deciduous or evergreen leaves. Flowers umbellate, corymbose, 

 or racemose, appearing- before or with the leaves, on branches of the same or the previous 

 season. Petals spreading, white or pink. Style terminal. Ovary and fruit glabrous or 

 pubescent. Drupe with a fleshy or sometimes dry, usually edible exocarp, and a bony 

 endocarp, which is smooth or roughened, globose-ovoid, or compressed. [Ancient Latin 

 name of the plum.] 



A genus of about 95 species, natives of the north temperate zone, tropical America, and Asia. Type species, 

 Prunus domestica L. 



Flowers corymbose or umbellate, appearing with or before the leaves on twigs of the previous season; leaves 

 deciduous. 



Drupe glabrous (somewhat pubescent in P. subcordata oregana), with a pulpy exocarp. (Prunus.) 



Leaves oblanceolate to oblong-obovate, narrowed at base; drupe 5-6 mm. long, bright red, very bitter. 



1. P. emargmata. 



Leaves orbicular to ovate, rounded or subcordate at base; drupe 20-25 mm. long, purple, edible. 



2. P. subcordata. 



Drupe pubescent, with an almost dry exocarp. (Emplectocladus.) 



Leaves ovate or suborbicular, rounded or subcordate at base, serrate. 3. P. Fremontii. 



Leaves spatulate to oblanceolate. 



Leaves glabrous, obscurely serrulate; flowers long-pedicelled, 10-15 mm. broad. 



A. P. Andersonn. 



Leaves usually pubescent, entire; flowers subsessile, 4-6 mm. broad. 5. P. fasciculata. 



Flowers in narrow racemes. 



Racemes terminating leafy branches of the season; drupe with a thick fleshy exocarp; leaves deciduous. 



(Padus.) 6 - P - demissa. 



Racemes in the axils of the leaves on the twigs of the previous season: drupe with a large stone and thin 

 exocarp; leaves evergreen, entire or spinulose-dentate. (Laurocerasus.) 

 Leaves conspicuously spinulose-dentate, strongly undulate-crisped, 2-4 cm. long. 7. P. ilicifolia. 



Leaves entire or occasionally sparsely spinulose-denticulate, plane or nearly so, 4-8 cm. long. 



8. P. Lyonn. 



