ROSACE, SILVA OF NORTH AMERICA. 87 
CRATAiGUS SERA. 
Haw. 
STAMENS 20; anthers pale yellow. Leaves oblong-ovate, membranaceous. 
Cratzgus sera, Sargent, Bot. Gazette, xxxiii. 115 (1902). 
A tree, from thirty to forty feet in height, with a tall straight trunk twelve or eighteen inches 
in diameter covered with pale slightly fissured bark, and thick branches forming a broad round- 
topped symmetrical head. The branchlets are slender, somewhat agzag, marked by small oblong pale 
lenticels, and unarmed, or armed with occasional straight slightly curved bright chestnut-brown lustrous 
spines from an inch and a quarter to an inch and a half in length; coated when they first appear with 
thick hoary tomentum, they are light red-brown and puberulous during their first summer, and ulti- 
mately pale orange-brown. The leaves are oblong-ovate, acute at the apex, rounded, truncate or 
slightly cordate, particularly on vigorous shoots, at the broad base, irregularly divided into four or five 
pairs of short acute lateral lobes, and sharply and sometimes doubly serrate nearly to the base, with 
straight glandular teeth; unfolding about the first of May with the opening of the flowers, they are 
then covered above with short soft white hairs and coated below with thick hoary tomentum ; and at 
maturity they are membranaceous, dark yellow-green and glabrous on the upper surface, pubescent 
on the lower surface, from two to four inches long and from two and a half to three inches wide, 
with slender midribs slightly impressed above and thin remote primary veins extending to the points 
of the lobes; they are borne on slender tomentose ultimately pubescent petioles which vary from an 
inch to an inch and a half in length. The stipules are linear, acute, glandular-serrate, villose, a quarter 
of an inch long, and on vigorous leading shoots often lunate, abruptly acuminate, and half an inch in 
length. The flowers are three quarters of an inch in diameter, and are borne in compact compound 
many-flowered tomentose corymbs, with lanceolate or oblanceolate coarsely glandular-serrate villose or 
tomentose bracts and bractlets. The calyx-tube is broadly obconic and coated with long matted pale 
hairs, and the lobes are broad, acute or acuminate, glandular-serrate, with large dark glands, tomentose 
on the outer surface, and villose on the inner surface. There are twenty stamens with pale yellow 
anthers, and four or usually five styles. The fruit ripens about the first of October and is borne on 
stout puberulous pedicels, in drooping few-fruited clusters; it is obovate or oblong, dull dark red, 
marked by small pale dots, usually slightly villose or pubescent at the ends, two thirds of an inch 
long and half an inch wide; the calyx-cavity is broad and shallow, and the lobes are enlarged, coarsely 
glandular-serrate, erect and incurved, and often deciduous before the ripening of the fruit; the flesh 
is thick, yellow, dry, and mealy. The four or usually five nutlets are thin, light brown, irregularly 
depressed on the back, with broad shallow grooves, and a quarter of an inch in length. 
Crategus sera grows in low moist ground in the neighborhood of streams on Belle Isle in the 
Detroit River, Michigan, and near Chicago, Illinois, on the bottoms of the Calumet and Desplaines 
rivers.! 
1 T first noticed this handsome Thorn-tree on Belle Isle in May, sera will be found to be common in southern Michigan, northern 
1899. It had been previously collected by Mr. E. J. Hill in rich Indiana, and northern and central Illinois. From Crategus mollis it 
woods adjacent to the Calumet River in 1896 and 1897, and near differs in its more oblong and much thinner leaves and in its late 
Glendon Park on the Desplaines River in 1900. Itis probable that ripening fruit. 
it has often been confounded with Crategus mollis, and that Crategus 
