Crataegus (sect. Coccineae) ser. Intricatae
Man. Cult. Trees ed. 2, 363. 1940.
Shrubs or trees, 10–60 (–80) dm, main trunk dominant. Stems: trunk bark gray and corrugated or buff to gray-brown and fibrous, checked into longitudinal plates, freshly exposed bark orangebrown; branches spreading; twigs ± straight, very rarely slightly flexuous, new growth usually glabrous, sometimes pubescent to tomentose, 1–2-years old gray to purple, purple-brown, reddish black or brown to very dark gray; thorns on twigs usually frequent, straight to recurved, 2-years old usually dark gray, almost black, sometimes purple or chestnut-brown, usually slender, (1–) 2–4 (–6) cm. Leaves: petiole length 20–66% blade, glabrous or pubescent, usually sessile, sometimes stipitate, glandular (often conspicuously so); blade mid to dark green, ovate, rhombic, elliptic, or broadly elliptic, (1.5–) 3–6 (–9) cm, thin to chartaceous, base cuneate to rounded, sometimes truncate to subcordate, lobes 0 or 1–4 (or 5) per side, sinuses shallow to ± deep, lobe apex usually acute, margins strongly serrate, often glandular, particularly toward base, venation craspedodromous, veins 3–5 (–7) per side, apex acuminate to obtuse, surfaces glabrous or pubescent. Inflorescences (2 or) 3–8-flowered, convex panicles; branches glabrous or hairy; bracteoles (not seen in 97. C. stonei and 98. C. ouachitensis), caducous, conspicuous, linear (oblong-linear in 96. C. biltmoreana), membranous (to nearly herbaceous in 90. C. intricata), margins stipitate-glandular, rarely shortly so. Flowers (12–) 14–20 (–22) mm diam.; hypanthium glabrous or hairy; sepals narrowly triangular (lanceolate in 95. C. nananixonii and 96. C. biltmoreana), much shorter than petals, margins glandular-serrate to glandular-pectinate; stamens (5–) 10 (–20), anthers ivory, cream, or pink to pale-purple; styles 2–5. Pomes dull yellow to orange, ruddy, russet, or scarlet to red, sometimes green, suborbicular, pyriform, obovoid, or oblong, sometimes broadly ellipsoid, (7–) 8–12 (–15) mm diam., glabrous or hairy; flesh ± hard to mealy; sepals usually on collar, patent to reflexed, nonaccrescent; pyrenes 2–5.
c, e United States
Species 12 (12 in the flora).
Members of ser. Intricatae are among the most characteristic hawthorns of the Appalachian foothills and valleys and extend beyond these areas less frequently. They are found in brush, open woodlands, and woodland edge habitats. The series includes the very rare Crataegus flava (the type of ser. Flavae), but ser. Intricatae is chosen for the name of the amalgamated series because, while both names have equal priority, the majority of ser. Flavae as previously understood are excluded from the combined series, and C. flava is now suspected of hybrid origin. Otherwise, ser. Intricatae is treated here in its traditional sense. Series Pulcherrimae, though always with 20 stamens, is similar to the glabrous inflorescence, southern elements of ser. Intricatae. This is seen particularly in the sometimes stipitate-glandular petioles, the usually densely bracteolate inflorescence, the bracteolar margins usually having relatively large, short-stipitate glands, and the fruiting calyx being usually elevated on a collar. Most varieties of C. chrysocarpa (ser. Rotundifoliae) also have similarities to hairy inflorescence members of ser. Intricatae but differ in lacking stipitate-glandular petioles, having less markedly glandular bracteoles, and having barely elevated fruiting calyx.
The most widespread members of ser. Intricatae are the glabrate Crataegus intricata and the hairy C. biltmoreana, while extremes of variation are toward the nearly entire-leaved C. padifolia among the glabrous group and the diminutive C. nananixonii among the hairy group.
|1||Inflorescence branches pubescent to villous or tomentose||> 2|
|1||Inflorescence branches glabrous or sparsely villous||> 6|
|2||Leaf blades 1.5–3.5 cm; shrubs 10–15 dm; stamens 10, anthers rose-purple; e Texas.||Crataegus nananixonii|
|2||Leaf blades (2–)3–8 cm; shrubs 10–60 dm; stamens (5–)10 or 20, anthers ivory to pale yellow, pink to purple; Louisiana to Florida and Missouri to Great Lakes and New England||> 3|
|3||Stamens 5–10||> 4|
|3||Stamens 20||> 5|
|4||Anthers cream; leaf blades narrowly to broadly ovate, lobes 3–5 per side, distinct; New England to Georgia and Arkansas.||Crataegus biltmoreana|
|4||Anthers pink; leaf blades narrowly ovate, lobes 0 or 1–3 per side, sinuses shallow; Massachusetts, New York, Pennsylvania.||Crataegus stonei|
|5||Anthers pink or rose to rose-purple; leaf blades ovate to deltate-ovate, (2–)3–4 cm; petioles 0.5 mm wide; leaf blade lobes 1–3 per side; pedicels ± tomentose young; Arkansas.||Crataegus ouachitensis|
|5||Anthers pale yellow or cream; leaf blades ovate to broadly elliptic, 4–8 cm; petioles 1–2 mm wide; leaf blade lobes 3 or 4 per side; pedicels pubescent; Appalachia.||Crataegus craytonii|
|6||Inflorescence branches glabrous or sparsely villous; stamens 13–16.||Crataegus flava|
|6||Inflorescence branches glabrous; stamens 10–20||> 7|
|7||Stamens 20; leaf blades ovate to deltate-ovate, 3–4 cm; petioles 0.5 mm wide.||Crataegus ouachitensis|
|7||Stamens 10(or 13–16); leaf blades ovate to elliptic, 2.5–8(–9) cm; petioles 1 mm wide||> 8|
|8||Leaf blades ± elliptic, rhombic-elliptic, or ± obtrullate to ± ovate, lobes 0 or mere apiculi, sinuses very shallow or margins sinuous||> 9|
|8||Leaf blades usually narrowly to broadly ovate, sometimes obovate or broadly elliptic, lobes evident, 1–5 per side, sinuses ± deep, margins not sinuous||> 10|
|9||Leaf blades rhombic-elliptic to ± obtrullate, marginal teeth strong; fruiting sepals on collar; pomes red to orange-red; e United States.||Crataegus rubella|
|9||Leaf blades elliptic to broadly elliptic, marginal teeth fine; fruiting sepals sessile; pomes dull orange-brown to ± shiny or red-orange to red; Ozarks.||Crataegus padifolia|
|10||Anthers ivory or cream||> 11|
|10||Anthers rose to purple||> 12|
|11||Shrubs 10–60 dm; leaf blades broadly elliptic to broadly ovate or oblong, lobe apices acute to acuminate, often reflexed; sepal margins glandular-serrate; pomes dull yellow to orange or russet; fruiting sepals on collar.||Crataegus intricata|
|11||Shrubs 40–60 dm; leaf blades ovate, lobe apices ± obtuse; sepal margins finely glandular-serrate distally; pomes red-orange to red; fruiting sepals sessile.||Crataegus padifolia|
|12||Leaf blades with sinuous lobes.||Crataegus flava|
|12||Leaf blades with acute or subobtuse lobes||> 13|
|13||Leaf blades usually ± ovate to broadly elliptic, sinuses shallow or moderately deep; pomes suborbicular||> 14|
|13||Leaf blades ± elliptic or rhombic-elliptic, sometimes ± obtrullate, sinuses shallow to non-existent; pomes usually oblong or short-oblong or obovoid, sometimes suborbicular||> 15|
|14||Shrubs, 20–40 dm; leaf blades trullate-ovate, bases ± cuneate, lobe apices acute; Ozarks, rare in se United States.||Crataegus neobushii|
|14||Shrubs or trees, 10–80 dm; leaf blades broadly elliptic to ovate or broadly ovate, bases broadly cuneate, lobe apices subacute; s Appalachia.||Crataegus buckleyi|
|15||Leaf blades ± elliptic or rhombic-elliptic, sometimes ± obtrullate, lobes 0, or 1 or 2 per side, sinuses shallow, lobe apices acute; pomes red to orange-red.||Crataegus rubella|
|15||Leaf blades broadly elliptic, lobes 0, or 2 or 3 per side, reduced to apiculi, lobe apices subobtuse; pomes yellow-green to dull orange, orange-red, or red.||Crataegus communis|