Crataegus (sect. Coccineae) ser. Pruinosae

Man. Cult. Trees ed. 2, 363. 1940.

Common names: Frosted thorns
Endemic
Basionym: Pruinosae Sargent Silva 13: 32. 1902
Treatment appears in FNA Volume 9. Treatment on page 571. Mentioned on page 516, 522, 527, 529, 535, 561, 564, 568, 572, 579, 637.

Shrubs or trees, (20–) 30–80 dm, main trunk dominant. Stems: trunk bark gray-brown, flattened-scaly, freshly exposed bark often orangebrown; branches spreading; twigs ± straight, new growth glabrous, 1-year old usually purple-brown, sometimes tan or reddish-brown, 2-years old grayish; thorns on twigs usually numerous, straight to recurved, 2-years old usually black or blackish, shiny, sometimes reddish-brown or purple, ± fine to slender or moderately thick, 1.5–5 cm. Leaves: petiole length (28–) 50–100% blade, glabrous, usually glandular, sometimes eglandular; blade mid to dark green or ± blue-green, ± ovate or ± trullate to rhombic or deltate, sometimes suborbiculate, (2–) 3–6 (–7) cm, thin to subcoriaceous, base cuneate to truncate, sometimes cordate or rounded, lobes (1–) 3 or 4 per side, sinuses shallow to moderately deep, lobe apex ± acute, sometimes ± obtuse, margins finely to coarsely serrate, venation craspedodromous, veins 4–7 per side, apex acute to obtuse, surfaces usually glabrous, sometimes adaxial sparsely hairy young. Inflorescences 4–10-flowered, convex panicles; branches usually glabrous, sometimes sparsely villous; bracteoles caducous, few to numerous, rarely absent, linear, membranous, margins sessile or short-stipitate-glandular. Flowers 15–30 mm diam.; hypanthium glabrous; sepals triangular, length 1/2 petal, margins usually subentire, sometimes entire, rarely glandular-serrate; stamens (10) 20, anthers white to pink or red, sometimes cream; styles 3–5. Pomes pink, mauve, or pale green, sometimes scarlet, deep crimson, or purple, suborbicular, (6–) 7–15 (–20) mm diam., strongly pruinose, glabrous; flesh hard (until overripe); sepals usually on prominent collar, spreading, nonaccrescent; pyrenes (2 or) 3–5, often angular.

Distribution

c, e North America

Discussion

Species 6 (6 in the flora).

Members of ser. Pruinosae are common from Wisconsin through the southern Great Lakes to southern Quebec and southern New England, to Arkansas and Louisiana to Georgia but absent from the southern coastal plain. In the north, they are found mainly in the open; southward they are more often found in woodland shade.

The core of ser. Pruinosae is a natural group of very thorny hawthorns with glabrous, somewhat blue-green, medium-sized to fairly large leaves, mid season anthesis relative to congeners, usually entire sepal margins, and hard, pruinose, often pink or mauve pomes, most with strikingly elevated fruiting calyx. All taxa except Crataegus pruinosa var. dissona have 20 stamens. Crataegus pruinosa var. virella, with the adaxial surface of younger leaves scabrous, might key to ser. Tenuifoliae when in flower. Crataegus gattingeri resembles C. iracunda (ser. Tenuifoliae) in fruit, though differing in leaf adaxial surface indumentum, leaf shape, stamen number, and anther size (see discussion below and under 58. C. iracunda). Members of ser. Pruinosae are similar to members of ser. Intricatae in many particulars, including range; they differ in bracteole form, fruit color, and leaf indumentum and often in stamen number.

The interserial hybrid Crataegus ×coleae keys out in the sixth couplet.

Selected References

None.

Key

1 Anthers 0.3–0.4 mm > 2
1 Anthers 0.6–0.8 mm > 3
2 Leaf blades trullate to rhombic-ovate, sinuses shallow, lobe apices subacute, bases cuneate, marginal teeth 1 mm. Crataegus compacta
2 Leaf blades ± deltate to narrowly ovate, sinuses shallow, lobe apices acute, bases rounded to broadly cuneate, marginal teeth 2 mm. Crataegus gattingeri
3 Leaf blades deltate, broadly elliptic, rhombic, or suborbiculate (widest near middle) > 4
3 Leaf blades ± ovate to oval, trullate, or broadly rhombic-elliptic (widest in basal 1/3) > 5
4 Anthers cream, pink, or red; flowers 20–24 mm diam. Crataegus suborbiculata
4 Anthers white; flowers 22–30 mm diam. Crataegus formosa
5 Anthers white. Crataegus cognata
5 Anthers pink to bright rose or dull purple, sometimes cream > 6
6 Pomes greenish with pink or mauve areas, sometimes bright crimson or scarlet, highly pruinose, not punctate; pyrene sides plane. Crataegus pruinosa
6 Pomes bright orange-red, at most slightly pruinose, punctate; pyrene sides each linearly scarred. Crataegus ×coleae
0.8 cm8 mm <br />0.008 m <br /> (2.5 cm25 mm <br />0.025 m <br />) +
cream +, white +  and pink or red +
James B. Phipps +
Loudon +
orangebrown +
thin-exfoliating +  and corrugated +
compound +  and simple +
opposite +  and alternate +
rounded +, cordate +, cuneate +  and truncate +
Pruinosae +
8 cm80 mm <br />0.08 m <br /> (12 cm120 mm <br />0.12 m <br />) +
mid +  and dark green +
broadly ovate +  and suborbiculate +
1 cm10 mm <br />0.01 m <br /> (8 cm80 mm <br />0.08 m <br />) +
few +  and numerous +
villous +  and glabrous +
adnate +  and distinct +
crowded +, scattered +  and alternate +
Frosted thorns +
c +  and e North America +
not +  and aggregated +
1.5 cm15 mm <br />0.015 m <br /> (3 cm30 mm <br />0.03 m <br />) +
unisexual +  and bisexual +
not +  and aggregated +
not +  and aggregated +
yellow +  and red or purplish +
0.6 cm6 mm <br />0.006 m <br /> (2 cm20 mm <br />0.02 m <br />) +
grayish +, reddish-brown +, tan +  and purple-brown +
old +  and new +
constricted +
0.2 cm2 mm <br />0.002 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
crassinucellate +
deciduous +
sessile +  and craspedodromous +
glandular-serrate +, entire +  and serrate +
subentire +
short-stipitate-glandular +
serrate +  and crenate +
inferior +  and superior +
biseriate +  and clustered +
collateral +  and basal +
0.8 cm8 mm <br />0.008 m <br /> (2.5 cm25 mm <br />0.025 m <br />) +
elliptic +  and circular +
0 (?) +  and 4 (?) +
free +  and distinct +
post-mature +
adnate +, free +, connate +  and distinct +
dark gray-brown +  and russet +
exfoliating +  and corrugated +
pruinose +
purple +, crimson +, deep +, scarlet +, pale green +, mauve +  and pink +
0.7 cm7 mm <br />0.007 m <br /> (1.5 cm15 mm <br />0.015 m <br />) +
suborbicular +
Man. Cult. Trees ed. +
not arillate +
persistent +
free +  and distinct +
triangular +
nonaccrescent +
1-50-flowered +  and few-leaved +
shallow +  and moderately deep +
free +  and distinct +
branched +  and simple +
persistent +
distinct +
exsert +  and lateral +
elongate +
hairy +  and glabrous +
Crataegus (sect. Coccineae) ser. Pruinosae +
Crataegus sect. Coccineae +
6 cm60 mm <br />0.06 m <br /> (10 cm100 mm <br />0.1 m <br />) +
purple +, reddish-brown +, blackish +, black +  and old +
straight +
slender +
1.5 cm15 mm <br />0.015 m <br /> (5 cm50 mm <br />0.05 m <br />) +
thick +  and fine +
craspedodromous +  and gland-tipped +
inconspicuous +
less erect +  and oblique +
1 +  and several +
straight +
determinate +
4 +  and 7 +
tree +  and shrub +