180 FLOEA OF PHILADELPHIA. 



2. Aronia nigra (Willd.) Britton. M. p. 517. Swamps, low woods; also 

 dry soil. Spring. 



4. AMELANCHIER Medic. Junebkrry, Shadbush, Serviceberry. 



Leaves acute or acuminate at the apex; top of the ovary glabrous or 

 nearly so. 

 Leaves ovate, oval or ovate-lanceolate, glabrous when mature ; base cor- 

 date or rounded. 1. A. Canadensis. 

 Leaves oblong, oval, ovate or obovate, rarely subcordate at base, densely 

 white-wooUy beneath, at least when young. 2. A. Botryapium. 

 Leaves rounded, obtuse or subacute at the apex; top of ovary woolly. 



3. A. spicata. 



1. AMELANCHIER CANADENSIS (L.) Medic. M. p. 517. Dry, open wood- 



lands. Spring. 



2. AMELANCHIER BoTRYAPiUM (L. f.) DC. M. p. 517. Low, moist grounds 



or swampy woods. Spring. 



3. AMELANCHIER SPICATA (Lam.) Dec. M. p. 517. Dry, rocky places. 



Spring. 

 Bucks— Bidge Road near Tylersport (Fr.), Naseville (Ja.). North- 

 ampton — Pot Rock in Delaware above Easton, Porter (B. C). 



5. CRATAEGUS i L. Hawthorn. 



CONSPECTUS OF THE NATURAL GROUPS. 



A. Indigenous species ; veins of the leaves attaining the points of the lobes 

 only. 

 I. Nutlets without ventral cavities. 



Petioles short, glandless or with occasional minute glands; leaves 

 obovate to oblong, oval or rarely ovate, cuneate at the base; 

 corjmibs many-flowered. 

 Leaves coriaceous, dark green and shining above, mostly quite 

 glabrous, usually serrate only above the middle, their veins 

 thin except on vigorous shoots and sometimes within the 

 parenchyma ; corymbs glabrous ; fruit oblong to subglobose ; 

 nutlets 1-3, generally obtuse and rounded at the ends, prom- 

 inently ridged at the back. I. Crus-gaUi. 

 Leaves membranaceous to subcoriaceous, mostly acute or occa- 

 sionally rounded at the apex, their veins prominent ; corymbs 

 villose; fruit usually short-oblong, often conspicuously punc- 

 tate; flesh dry and mealy; nutlets 2-5, prominently ridged 

 on the back. TI. Punctatae. 

 Petioles elongated, usually slender (short and stout in Uniflorae), 

 glandular only toward the apex (in Intricatae sparingly 

 glandular throughout). 

 Leaves mostly broad at the base. 



Corymbs many-flowered (few-flowered in some species of 

 Pruincsae). 

 Fruit subglobose to short-oblong, rarely pyriform, red 

 or green, often slightly 5-angled, generally pruinose, 

 especially during the summer; leaves blue-green, 

 thin and firm to subcoriaceous or rarely coriaceous. 



III. Pruinosae. 

 Fruit short-oblong to obovate, ovate or subglobose, 



'Prepared by Mr. B. H. Smith. Based mainly upon the studies of Prof. C. S. Sargent in 

 The Genus Crataegus in New Castle County, Delaware, Botanical Gazette, xxxv, 99- 

 110, February, 1908, and Crataegus in Eastern Pennsylvania, Proceedings of the Acad- 

 emy of Natural Sciences of Philadelphia, Ivii. 



