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PLANTS OF YELLOWSTONE NATIONAL PARK 
Woods rose ( Rosa woodsii) is much like the preceding species but is 
only 1 to 3 feet high, and the flowers are about 2 inches across. 
Bourgeau rose ( Rosa bourgeauiana) has also been reported in the 
park. 
APPLE PAMILY (POMACEAE) 
The chief distinction between the apple family and the rose family 
is that in the rose family the simple pistils are distinct, while in the 
apple family they are united into a compound pistil the ovary of 
which is surrounded by, and united with, the receptacle, so that the 
parts of the flower are attached above the ovary. The members of 
the family are all trees or shrubs, and many of them have edible 
fruits, most notably the various kinds of apples and pears. 
Saskatoon ( Amelanchier 
alnifolia) A shrub or 
small tree 6 to 12 feet high 
with simple, alternate 
leaves and dense clusters 
of white flowers. It is 
smooth throughout. The 
fruit is purple when ripe 
and is sweet and juicy. 
Also called serviceberry, 
shadbush, and Juneberry. 
Amelanchier elliptica is 
distinguished by the fact 
figure 57.— Saskatoon. White. Photograph by that the twigs, leaves, and 
Dr. Harvey E. Stork. . ’ ’ 
calyx are more or less 
hairy. The flowers are fewer but larger. 
Greene mountain-ash (Sorbus scopulina). —A stout shrub, 3 to 12 
feet high, with alternate, pinnate leaves and white flowers borne 
in flat-topped clusters. The 11 to 15 leaflets are oblong or lance¬ 
shaped and sharply toothed. The fruits are red and bitter. 
PLUM PAMILY (DRUPACEAE) 
The plum family differs from the rose and apple families by 
having the parts of the flower attached to the edge of a cup-shaped 
receptable, around the ovary but entirely free from it, and the fruit 
is a drupe or stone-fruit. The family seems to be represented here 
only by the Black chokecherry ( Prunus melanocarpa) , a shrub or 
small tree, 3 to 15 feet high, with alternate, ovate or oblong and 
finely toothed leaflets and white flowers borne in dense racemes. 
The fruits when fully mature are black. 
