ROSACEiE 365 



ornaments of parks and gardens, and several are cultivated. Of exotic species, the Old 

 World Cratcegus Oxyacantha, L., early introduced into the United States as a hedge 

 plant, has now become naturalized in many places in the northeastern and middle 

 states. Crataegus produces heavy hard tough close-grained red-brown heart wood 

 and thick lighter colored usually pale sap wood ; useful for the handles of tools, mal- 

 lets, and other small articles. 



The number of the stamens, although it differs on the same species within certain 

 usually constant limits, and the color of the anthers, which appears to be specifically 

 constant with two exceptions, afford the most satisfactory characters for distinguish- 

 ing the species in the different groups. 



Cratcegus, from Kparos, is in reference to the strength of the wood of these trees. 



CONSPECTUS OF THE NATURAL GROUPS OF THE NORTH 

 AMERICAN ARBORESCENT SPECIES. 



1. Nutlets without ventral cavities. 



*Veins of the leaves extending to the points of the lobes only. 

 -*-Petioles short, glandless or with occasional minute glands ; leaves obovate to ob- 

 long, cuneate at the base. 

 -M-Corymbs many-flowered. 



Leaves coriaceous or subcoriaceous, rarely thin, dark green and shining 

 above, usually serrate only above the middle, their veins thin except on 

 vigorous shoots ; fruit mostly globose to short-oblong, g-'-l' long, with 

 thin bright usually greenish flesh ; nutlets 1-3, thick, usually obtuse 

 and rounded at the ends, prominently ridged on the back. 



I. Crus-galli (page 367). 

 Leaves membranaceous or subcoriaceous, mostly acute, their veins promi- 

 nent; fruit oblong to globose, often conspicuously punctate, g-'-l' long; 

 flesh dry and mealy ; nutlets 2-5, prominently ridged on the back. 



II. Punctatae (page 388). 

 t-t-++ Corymbs few-flowered; flowers appearing with or before the unfolding of 

 the leaves ; "stamens 20-25 ; anthers large, dark rose color. 



III. -Slstivales (page 399). 



-t- -t-Petioles elongated, slender, glandless or with occasional minute glands ; leaves 



membranaceous to subcoriaceous, acute or acuminate at the ends, on one species 



broad at the base; corymbs many-flowered ; fruit subglobose to oblong, g'-f 



long. IV. Virides (page 400). 



- -+ -t- Petioles elongated, usually slender, glandular only at the apex (in Intricatce and 



BracteatcB sparingly glandular throughout). 



^Leaves mostly broad at the base ; corymbs many-flowered {few-flowered in 



one species of Dilatatce)'. 



Fruit subglobose to short-oblong, i'-f ' in diameter, red or green, often 

 slightly 5-angled, pruinose ; nutlets 5, grooved on the back ; stamens 20 ; 

 anthers rose color ; leaves blue-green, subcoriaceous, nearly glabrous. 



V. Pruinosae (page 411). 

 Fruit short-oblong to obovate, scarlet, 4^'-|' long, globose and greenish red 

 in one species ; flesh succulent, sometimes juicy ; anthers rose color or 

 purple ; leaves membranaceous, at maturity glabrous below. 



VI. Tenuifoliae (page 413). 

 Fruit subglobose, oblong or pyriform, crimson, scarlet, or rarely yellow, 

 usually about 1' in diameter; flesh thick, succulent, often edible; nut- 

 lets usually 5, occasionally 4, thin, pointed at the ends, mostly obscurely 



