This section is from the book "An Illustrated Flora Of The Northern United States, Canada And The British Possessions Vol2", by Nathaniel Lord Britton, Addison Brown. Also available from Amazon: An Illustrated Flora of the Northern United States, Canada and the British Possessions. 3 Volume Set..
C. lucorum Sarg. Bot. Gaz. 31: 227. 1901.
A shrub or tree, with ascending branches, the spines 1'-1 1/2' long. Leaves oblong-ovate to broadly ovate, ii'- 2 1/2' long, 3/4'-2' wide, acute or acuminate at the apex, •broadly cuneate or rounded at base, serrate or doubly serrate or lobed towards the apex, membranous, dark dull green above, glabrous and pale beneath; corymbs slightly villous; flowers about 10" broad; stamens about 20; anthers small, purple; styles and nutlets 4 or 5; calyx-lobes nearly glabrous on the inner surface, slightly glandular-serrate; fruit pyriform-ellipsoid, crimson, 5" or 6" thick, glabrous; calyx-lobes reflexed; flesh soft, succulent.
Northen Illinois and Wisconsin. May; fruit ripe September.
C. irrasa Sarg. Rhodora 5: 116. April 1903.
Crataegus irrasa var. divergens Peck, Bull. N. Y. State Mus. 75: 51. 1904. C. Blanchardi Sarg. Rhodora 7: 218. 1905.
A shrub, sometimes 12° high, with numerous spines 1'-3 1/2' long. Leaves ovate to elliptic, acute at the apex, broadly cuneate or truncate at the base, serrate, with 4-6 pairs of acute lobes, 1 1/4'-2 1/2' long, 1 1/4'-2 1/2' wide, membranous, slightly pubescent above, becoming glabrous but remaining pubescent along the veins beneath; corymbs villous; flowers about 8" broad; stamens about 20; anthers yellow or pink; styles and nutlets 3-5; fruit subglobose to short-ellipsoid, about 5" thick, slightly angled, red or scarlet, somewhat pubescent; calyx-lobes persistent; flesh soft, reddish.
A round-topped tree, sometimes 20o high, with somewhat pendulous branches. Leaves ovate to oval, 1 1/2'-2 1/2' long, 1 1/4'-2' wide, acute, broadly cuneate or rounded at the base, doubly serrate or lobed, dark yellow-green and shining above, membranous, glabrous; corymbs many-flowered, glabrous; flowers 8"-9" broad; calyx-lobes glabrous or pubescent on the inside, lanceolate, acuminate; stamens about 20; anthers yellow, small; styles and nutlets 4 or 5; fruit subglobose to short-ellipsoid, dark crimson, 5" or 6" thick, the calyx-tube prominent; flesh thin, yellow, dry.
Central and western New York. May; fruit ripe October.