328 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM, 
Rydberg, in his recent treatment of the genus in the North American Flora, recognizes 
6 species in this group. The characters relied upon, however, are not at all convincing. 
P. confusus Piper is considered a valid species; P. columbianus Koehnea supposed to be 
from British Columbia, is identified with specimens here referred to P. gordonianus; and 
P. angustifolius Rydberg? is described from specimens collected at ‘Palace Camp” on 
the Willis trail to Mount Rainier. 
ROSACEAE. Rose Faminy. 
Carpels few, in fruit becoming 2 to several-seeded follicles or capsules; 
shrubs. 
Leaves palmately lobed; pods 2-valved...........-.-.-.-.- OpPuLasTer (p. 329). 
Leaves not palmately lobed. 
Stamens united at base; leaves twice or thrice palmately 
3-cleft; flowers racemose . __...- ee eee ee eee Lurkea (p. 329). 
Stamens not united at base; flowers in panicles or corymbs. 
Stamineal disk adherent, entire; ovules 2......... . Scuizonotus (p. 330). 
Stamineal disk free at the edge, not entire; ovules 
several. 
Shrubs with simple leaves; flowers perfect... . - SPIRAEA (p. 330). 
Herbs with compound leaves; flowers dioecious. ArUNCUS (p. 332). 
Carpels few to many, becoming akenes or drupelets in fruit. 
Fruit consisting of druplets, usually united .....2. 2.2.22... Rubus (p. 332). 
Fruit consisting of akenes. 
Akenes in fruit inclosed in the more or less enlarged tur- 
binate or campanulate receptacle. 
Receptacle cup-shaped and fleshy in fruit; prickly 
shrubs with pinnate leaves......-.2...2.22-.--- Rosa (p. 334). 
Receptacle dry in fruit; herbs. 
Petals yellow; calyx prickly. ...-... 2.2.22... AGRIMONIA (p. 335). 
Petals none; calyx not prickly. 
Leaves palmately lobed; flowers axillary... ALCHEMILLA (p. 335). 
Leaves pinnate; flowers spicate........... SANGUISORBA (p. 335). 
Akenes in fruit on a plane or merely concave receptacle. 
Herbs. 
Styles deciduous, naked, terminal or lateral. 
Styles terminal. 
Stamens inserted near the base of the 
receptacle cup on an annular thicken- 
ing; flowers yellow ............-.- POTENTILLA (p. 336). 
Stamens inserted well up in the recep- 
tacle cup; no annular thickening... Horkevta (p. 339). 
Styles lateral. 
Carpels hairy; shrubs... ..........-.- DasipHora (p. 341). 
Carpels glabrous; herbs. 
Stamens 5; carpels 10 to 15; leaves 
trifoliolate ... 2.2... .2...22.- SIBBALDIA (p. 340). 
Stamens 20; carpels numerous. 
Leaves trifoliolate; receptacle 
fleshy in fruit; petals white. FraGarta (p. 340). 
Leaves pinnate; receptacle 
not fleshy. 
aGartenflora 1896: 542, 1896. oN. Am. FI. 227: 166. 1905. 
