Crataegus (sect. Coccineae) ser. Tenuifoliae

Man. Cult. Trees ed. 2, 362. 1940.

Endemic
Basionym: Tenuifoliae Sargent Silva 13: 34. 1902
Synonyms: Crataegus sect. Tenuifoliae (Sargent) Eggleston
Treatment appears in FNA Volume 9. Treatment on page 561. Mentioned on page 494, 522, 527, 528, 530, 558, 566, 568, 569, 572, 573, 591, 594, 600, 641, 642.

Shrubs or trees, 20–70 (–80) dm, main trunk dominant. Stems: trunk bark buff to gray-brown, fibrous, checked into longitudinal plates, freshly exposed bark orangebrown; branches spreading; twigs ± straight, new growth usually glabrous, sometimes sparsely pubescent, 1-year old deep reddish-brown, older gray; thorns on twigs usually numerous, usually recurved, 1-year old shiny, dark-brown to black, stout to slender, 2.5–6 cm. Leaves: petiole 1–3 cm, length 30–60% blade, glabrous, sessile-glandular or eglandular; blade pale green abaxially, mid dark green adaxially, elliptic to ovate or ovate-deltate, 3–6 (–8) cm, thin to chartaceous, base cuneate to rounded or truncate to subcordate, lobes 0 or 3–6 per side, sinuses shallow to deep, lobe apex usually acute, margins serrate, venation craspedodromous, veins (3 or) 4–7 per side, apex usually acute, sometimes subacute or acuminate, abaxial surface glabrous, veins pilose young in some, adaxial appressed-scabrous-pubescent young, glabrescent. Inflorescences (4 or) 5–10 (–20) -flowered, convex panicles; branches glabrous or villous; bracteoles caducous, absent or few to several, narrow, membranous, margins short-stipitate-glandular. Flowers (10–) 13–17 (–26) mm diam.; hypanthium usually glabrous, sometimes villous at base; sepals narrowly triangular, much shorter than petals, margins subentire or glandular-serrate, rarely nearly eglandular; stamens 5–10 or 20, anthers pink to red or purple; styles 3–5. Pomes red, rarely with orange or orange-red spots, ellipsoid to suborbicular, sometimes broadly pyriform, 8–15 (–20) mm diam., glabrous; flesh mellow; sepals erect-patent to recurved or erose, nonaccrescent; pyrenes (2 or) 3–5.

Discussion

Species 7 (7 in the flora).

Members of ser. Tenuifoliae range through nearly the whole of the eastern United States (except Florida) and also in adjacent Canada. Crataegus wootonianais a disjunct species in the mountains of New Mexico.

Relatively small and thin leaves, entire or weakly serrate sepals, and pink to reddish anthers characterize most ser. Tenuifoliae. Bracteole frequency in this series appears to correlate positively with inflorescence hairiness; the species flower relatively early among sympatric congeners and are often strikingly tinged with anthocyanins at leaf expansion.

Members of ser. Tenuifoliae are most similar to those of ser. Coccineae (the latter usually being larger in all parts and usually more hairy), to ser. Rotundifoliae via Crataegus flabellata, and to some members of ser. Populneaeae, this last series a grouping of taxa intermediate between ser. Pruinosae and ser. Tenuifoliae.

The interserial hybrids Crataegus ×fretalis and C. ×lucorum key out in the eighth and fourth couplets, respectively.

Selected References

None.

Key

1 Stamens ca. 20 > 2
1 Stamens 5–10 > 6
2 Inflorescence branches glabrous > 3
2 Inflorescence branches hairy > 4
3 Leaf marginal teeth 1 mm; leaf blades on extension shoots ovate. Crataegus schuettei
3 Leaf marginal teeth 1.5–3 mm; leaf blades on extension shoots suborbiculate or broadly deltate. Crataegus roribacca
4 Leaf lobe apices acute, lobe sinuses shallow to moderately deep; anthers purple; adaxial leaf surfaces glabrous. Crataegus ×lucorum
4 Leaf lobe apices acute to acuminate, lobe sinuses deep; anthers usually pink or red; adaxial leaf surfaces appressed-scabrous young > 5
5 Leaf blades narrowly ovate; inflorescence branches sparsely pubescent. Crataegus schuettei
5 Leaf blades broadly elliptic to ovate; inflorescence branches villous. Crataegus flabellata
6 Inflorescence branches hairy > 7
6 Inflorescence branches glabrous > 8
7 Leaf blades not glossy, mid green, lobes usually acute, sinuses shallow to moderately deep; sepal margins usually eglandular, subentire in c and e of range; Minnesota to Quebec and Maine, uncommon in area of sympatry with C. flabellata. Crataegus fluviatilis
7 Leaf blades glossy, dark green, lobes acuminate, sinuses deep; sepal margins usually glandular, often serrate; Ontario to New England and Nova Scotia. Crataegus flabellata
8 Sepal margins coarsely glandular-serrate. Crataegus ×fretalis
8 Sepal margins usually subentire > 9
9 Leaves 40–60% mature size at anthesis; Louisiana to South Carolina piedmont north to se Virginia coastal plain. Crataegus iracunda
9 Leaves 70–100% mature size at anthesis; New Mexico or ne and midwestern United States and adjacent Canada south in the Appalachians at high altitudes to Georgia > 10
10 Flowers 13–17(–22) mm diam.; leaf sinuses moderately deep; petioles sparsely to densely glandular; e North America. Crataegus macrosperma
10 Flowers 10–12 mm diam.; leaf sinuses shallow; petioles eglandular or sparsely glandular; New Mexico. Crataegus wootoniana
appressed-scabrous-pubescent +
0.8 cm8 mm <br />0.008 m <br /> (2.5 cm25 mm <br />0.025 m <br />) +
pink +  and red or purple +
James B. Phipps +
Loudon +
orangebrown +
thin-exfoliating +  and corrugated +
compound +  and simple +
opposite +  and alternate +
cuneate +  and rounded or truncate +
Tenuifoliae +
8 cm80 mm <br />0.08 m <br /> (12 cm120 mm <br />0.12 m <br />) +
broadly ovate +  and suborbiculate +
1 cm10 mm <br />0.01 m <br /> (8 cm80 mm <br />0.08 m <br />) +
few +  and several +
villous +  and glabrous +
adnate +  and distinct +
crowded +, scattered +  and alternate +
North America +
not +  and aggregated +
1.3 cm13 mm <br />0.013 m <br /> (1.7 cm17 mm <br />0.017 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 />) +
gray +  and reddish-brown +
older +, old +  and new +
pubescent +  and glabrous +
villous +  and glabrous +
constricted +
0.2 cm2 mm <br />0.002 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
5-10(-20)-flowered +
crassinucellate +
deciduous +
eglandular +  and craspedodromous +
glandular-serrate +  and serrate +
short-stipitate-glandular +
subentire +
6 cm60 mm <br />0.06 m <br /> (8 cm80 mm <br />0.08 m <br />) +
3 cm30 mm <br />0.03 m <br /> (6 cm60 mm <br />0.06 m <br />) +
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 +
eglandular +  and sessile-glandular +
1 cm10 mm <br />0.01 m <br /> (3 cm30 mm <br />0.03 m <br />) +
adnate +, free +, connate +  and distinct +
dark gray-brown +  and russet +
exfoliating +  and corrugated +
pruinose +
Man. Cult. Trees ed. +
not arillate +
persistent +
free +  and distinct +
erect-patent +  and recurved +
triangular +
nonaccrescent +
1-50-flowered +  and few-leaved +
shallow +  and deep +
free +  and distinct +
branched +  and simple +
persistent +
distinct +
exsert +  and lateral +
elongate +
glabrous +  and tomentose +
Crataegus sect. Tenuifoliae +
Crataegus (sect. Coccineae) ser. Tenuifoliae +
Crataegus sect. Coccineae +
6 cm60 mm <br />0.06 m <br /> (10 cm100 mm <br />0.1 m <br />) +
dark-brown +  and black +
straight +
stout +  and slender +
2.5 cm25 mm <br />0.025 m <br /> (6 cm60 mm <br />0.06 m <br />) +
craspedodromous +  and gland-tipped +
inconspicuous +
less erect +  and oblique +
1 +  and several +
straight +
determinate +
glabrescent +  and pilose +
4 +  and 7 +
tree +  and shrub +