Crataegus suborbiculata

Sargent

Rhodora 3: 72. 1901.

Conservation concernEndemic
Treatment appears in FNA Volume 9. Treatment on page 574. Mentioned on page 572.

Shrubs or trees, 80 dm. Stems: twigs: new growth reddish, 1-year old tan, 2-years old light gray; thorns on twigs straight, 2-years old blackish, usually shiny, ± slender, 2.5–4.5 cm. Leaves: petiole length 50–100% blade, eglandular or with 1–2 (–3) glands; blade broadly elliptic or rhombic to suborbiculate, 4–6 cm, thin, base cuneate to broadly cuneate, lobes 3 or 4 per side, sinuses shallow, lobe apex acute, margins serrate, eglandular, veins 5 or 6 per side, apex acute to obtuse, surfaces glabrous, adaxial sparsely hairy young. Inflorescences 5–10-flowered; branches glabrous; bracteoles sometimes absent, margins glandular. Flowers 20–24 mm diam.; sepals narrowly triangular, 5–6 mm, margins subentire, abaxially glabrous; stamens 20, anthers cream, pink, or red, 0.7 mm; styles 4. Pomes pink mauve, ripening to orange-red or purplish, 10–14 mm diam., pruinose at first; sepals not on collar, spreading; pyrenes 3 or 4.2n = 68.


Phenology: Flowering May–Jun; fruiting Sep–Oct.
Habitat: Woodland margins, brush
Elevation: 50–300 m

Distribution

V9 976-distribution-map.jpg

Ont., Que., Conn., Mich., N.Y.

Discussion

Of conservation concern.

Crataegus suborbiculata is uncommon but is found in a number of locations in southern Ontario, and extends east to Quebec, New York, and Connecticut, and west to Michigan. Fruiting specimens, seemingly of this species but in poor condition, have been collected along the Skyline Drive of Virginia.

Very rare forms with slight inflorescence pilosity may occur and then Crataegus suborbiculata may look very much like some forms of C. florifera (ser. Anomalae), which is distinguished by its pyrenes. One large Ontario population is rather similar to C. compacta except that it is larger in all its parts and has proportionately slightly wider leaves. Very rare forms with narrower leaves (elliptic-rhombic) and small anthers may be referred to C. nitidula Sargent, known from southern Ontario, Michigan, Pennsylvania, and Wisconsin. Forms named C. umbratilis Sargent from Connecticut and Pennsylvania have slightly larger, more venous leaves with larger marginal teeth than the above and an elevated calyx in fruit. The poorly understood C. durobrivensis Sargent was suggested by E. J. Palmer (1952) to be a hybrid with C. pruinosa.

Selected References

None.

Lower Taxa

None.

"eglandular" is not a number.

... more about "Crataegus suborbiculata"
0.8 cm8 mm <br />0.008 m <br /> (2.5 cm25 mm <br />0.025 m <br />) +
red +, pink +  and cream +
0.7 cm7 mm <br />0.007 m <br /> (?) +
James B. Phipps +
Sargent +
orangebrown +
thin-exfoliating +  and corrugated +
compound +  and simple +
opposite +  and alternate +
cuneate +  and broadly cuneate +
Pruinosae +
8 cm80 mm <br />0.08 m <br /> (12 cm120 mm <br />0.12 m <br />) +
mid +  and dark green +
rhombic +  and suborbiculate +
4 cm40 mm <br />0.04 m <br /> (6 cm60 mm <br />0.06 m <br />) +
few +  and numerous +
adnate +  and distinct +
crowded +, scattered +  and alternate +
Ont. +, Que. +, Conn. +, Mich. +  and N.Y. +
not +  and aggregated +
50–300 m +
2 cm20 mm <br />0.02 m <br /> (2.4 cm24 mm <br />0.024 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 />) +
light gray +, tan +  and reddish +
old +  and new +
Woodland margins, brush +
constricted +
0.2 cm2 mm <br />0.002 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
crassinucellate +
deciduous +
subentire +
subentire +
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 +
with 1-2(-3) glands +
Flowering May–Jun +  and fruiting Sep–Oct. +
adnate +, free +, connate +  and distinct +
dark gray-brown +  and russet +
exfoliating +  and corrugated +
pruinose +
purplish +, orange-red +  and pink mauve +
1 cm10 mm <br />0.01 m <br /> (1.4 cm14 mm <br />0.014 m <br />) +
suborbicular +
not arillate +
persistent +
free +  and distinct +
triangular +
nonaccrescent +
0.5 cm5 mm <br />0.005 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
1-50-flowered +  and few-leaved +
Conservation concern +  and Endemic +
free +  and distinct +
branched +  and simple +
persistent +
distinct +
exsert +  and lateral +
elongate +
Crataegus suborbiculata +
Crataegus (sect. Coccineae) ser. Pruinosae +
species +
6 cm60 mm <br />0.06 m <br /> (10 cm100 mm <br />0.1 m <br />) +
straight +
slender +
2.5 cm25 mm <br />0.025 m <br /> (4.5 cm45 mm <br />0.045 m <br />) +
thick +  and fine +
craspedodromous +  and gland-tipped +
inconspicuous +
less erect +  and oblique +
1 +  and several +
straight +
determinate +
6 +  and 5 +
tree +  and shrub +