32 
SILVA OF NORTH AMERICA. 
ROSACEA. 
however, several variations from this arrangement, and the number of styles and nutlets appears a less 
satisfactory character for distinguishing species than 
the number of stamens. The nature and amount 
of the hairy covering of the young branchlets, leaves, and calyx, and the time of flowering and of the 
ripening and falling of the fruit of Crataegus also afford useful characters for determining species.' 
1 In this restudy of the genus Crategus I have been assisted by 
many correspondents, particularly by Mr. C. D. Beadle of the 
Biltmore Herbarium, Mr. William M. Canby of Wilmington, Del- 
aware, Mr. B. F. Bush of Courtney, Missouri, Mr. E. J. Hill of 
Chicago, Illinois, Mr. D. W. Beadle of Toronto, Ontario, Mr. C. 
C. Laney and Mr. John Dunbar of the Park Department of the 
city of Rochester, New York, Miss Emma J. Cole of Grand 
Rapids, Michigan, Mr. J. G. Jack of the Arnold Arboretum, Mr, 
A. H. Curtiss of Jacksonville, Florida, Mr. Julius Reverchon of 
Dallas, Texas, and Mr. J. B. S. Norton of the Missouri Botanical 
Garden. 
CONSPECTUS OF THE NORTH AMERICAN ARBORESCENT SPECIES. 
MaAcrocarRP2&. 
Fruit medium size, black or blue; nutlets 5, grooved or ridged on the back; corymbs many- 
flowered. Melanocarpe. 
Leaves broadly ovate to oblong-ovate. 
Leaves rhombic or oval. Fruit blue-black 
Leaves oblong-lanceolate to ovate. 
slightly pruinose; nutlets 2 or 3 (Nos. 9, 3-4, 11, 3-5), 
Fruit black . 
Fruit bright blue . : 
Fruit medium size, dull red or green tinged with red (except Nos. 6, 7, 10, 13, and 15), often 
. Doveuasit.? 
. SALIGNA. 
. BRACHYACANTHA. 
bo 
obtuse, prominently ridged on the 
back ; corymbs many-flowered ; leaves subcoriaceous (except Nos. 8, 11, and 13), dark green 
and lustrous. Crus-galli. 
Stamens 10. 
Anthers rose color or purple. 
Leaves obovate-cuneiform to broadly ovate 
Leaves oblong-oval to ovate, usually acute . 
Leaves obovate or elliptical, villose . 
Leaves obovate, usually short-pointed 
Leaves thin, oblong-obovate to oval or broadly ovate 
Anthers probably yellow (No. 11 doubtful). 
Leaves broadly oval to obovate 
Leaves oval te oblong-obovate, acute or acuminate 
Leaves thin, obovate, rounded or acute . 
Stamens 20. 
Anthers rose color. 
Leaves obovate to elliptical . : 
Leaves thin, obovate, rounded at the apex, villose 
Leaves oblong-obovate, acute, scabrate . 
Anthers yellow. 
Leaves usually obovate, acute . 
Fruit medium size, red or green, often slightly five-angled, pruinose; nutlets 5, more or less 
. CRUS-GALLI. 
. CANBYI. 
. ENGELMANNI. 
PrEORIENSIS. 
. FECUNDA. 
- ERECTA. 
- ACUTIFOLIA. 
- SIGNATA. 
. Busurt. 
. BERBERIFOLIA. 
EDITA. 
. Mouri. 
grooved on the back; corymbs many-flowered ; stamens 20; anthers rose color; leaves blue- 
green, subcoriaceous, nearly glabrous. Pruinose. 
Leaves elliptical to ovate 
Leaves ovate, acute or acuminate 
Fruit medium size, greenish red or yellow; nutlets 3-5, ridged on the back; corymbs few- 
flowered ; leaves subcoriaceous, yellow-green. 
Stamens 10; anthers yellow. 
Leaves ovate or oval . 
Stamens 15-20 ; 
Leaves oval to ovate, acute . 
anthers yellow. 
Intricate. 
16. 
17. 
PRUINOSA. 
GEORGIANA. 
18. Boyntont. 
19. VENUSTA. 
