Crataegus ×rufula

Crataegus ×rufula Sargent

J. Arnold Arbor. 1: 251. 1920.

Common names: Rufous mayhaw
Endemic
Treatment appears in FNA Volume 9. Treatment on page 548. Mentioned on page 546, 547.

Shrubs or trees, 30–50 dm. Stems: twigs: new growth rusty-tomentose, 1-year old chestnut-brown; thorns on twigs 2-years old dark gray to black, 1–3 (–5) cm. Leaves: petiole length 10–15% blade; blade elliptic to ovate, 2.5–4.5 cm, lobes 0 or sinuate (those on rapidly elongating shoots larger, usually proportionately wider than those on short-shoots, sinuately lobed), margins entire or barely serrate or crenate in distal 1/3 or 1/2, teeth gland-tipped, veins 3–5 per side, apex subacute to obtuse, abaxial surface densely rufous-tomentose, especially on veins, adaxial densely white or rufous-tomentose young, scabrous mature. Inflorescences 2–5-flowered umbels; branches glabrous or rufous-tomentose; bracteoles narrow, margins glandular. Flowers ± precocious, 15–27.5 mm diam.; hypanthium glabrous or rufous-tomentose; sepal margins entire or slightly glandular-serrate; petals 12 mm; anthers red; styles (4 or) 5. Pomes red, 10 mm diam.; sepals short-triangular; pyrenes 5.2n = 34, 51.


Phenology: Flowering Feb–Mar; fruiting May–Jun.
Habitat: Seasonally inundated depressions, ditches, sink holes, streamsides
Elevation: 10–100 m

Discussion

Crataegus ×rufula is restricted to the Florida panhandle and adjacent Georgia and southeastern Alabama.

Crataegus ×rufula is a presumed hybrid between the other two mayhaws or descendants thereof (J. B. Phipps 1988b) as shown by morphometric analyses. Although in some characteristics (for example, the usually sinuate leaf margin) C. ×rufula is like C. opaca, it lacks the characteristic elongate leaves of the latter. Crataegus ×rufula also tends to intergrade with C. aestivalis, with which it is fully sympatric. The frequency of C. aestivalis-like intermediates could well be accounted for by pure C. aestivalis being reasonably common through the C. ×rufula range and C. opaca being scarce there. Some, not all, individuals of C. ×rufula have relatively large flowers. Crataegus ×rufula is locally common and conveniently treated as a species.

Selected References

None.

Lower Taxa

None.
... more about "Crataegus ×rufula"
mature +  and young +
0.8 cm8 mm <br />0.008 m <br /> (2.5 cm25 mm <br />0.025 m <br />) +
glossy +  and matte +
James B. Phipps +
Crataegus ×rufula Sargent +
thin-exfoliating +  and corrugated +
compound +  and simple +
opposite +  and alternate +
cuneate +
Aestivales +
8 cm80 mm <br />0.08 m <br /> (12 cm120 mm <br />0.12 m <br />) +
elliptic +  and ovate +
2.5 cm25 mm <br />0.025 m <br /> (4.5 cm45 mm <br />0.045 m <br />) +
rufous-tomentose +  and glabrous +
adnate +  and distinct +
crowded +, scattered +  and alternate +
Rufous mayhaw +
Ala. +, Fla. +  and Ga. +
not +  and aggregated +
10–100 m +
succulent +
1.5 cm15 mm <br />0.015 m <br /> (2.75 cm27.5 mm <br />0.0275 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 />) +
chestnut-brown +
old +  and new +
rusty-tomentose +
Seasonally inundated depressions, ditches, sink holes, streamsides +
rufous-tomentose +  and glabrous +
constricted +
0.2 cm2 mm <br />0.002 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
crassinucellate +
umbellate +  and 2-6-flowered +
deciduous +
sinuate +
craspedodromous +  and eglandular +
barely serrate or crenate +  and entire +
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 +
12 cm120 mm <br />0.12 m <br /> (?) +
rufous-tomentose +  and glabrous +
Flowering Feb–Mar +  and fruiting May–Jun. +
adnate +, free +, connate +  and distinct +
dark gray-brown +  and russet +
exfoliating +  and corrugated +
pruinose +
10 cm100 mm <br />0.1 m <br /> (?) +
suborbicular +
J. Arnold Arbor. +
not arillate +
persistent +
free +  and distinct +
short +  and much shorter +
glandular-serrate +  and entire +
short-triangular +
accrescent +
1-50-flowered +  and few-leaved +
free +  and distinct +
branched +  and simple +
persistent +
distinct +
exsert +  and lateral +
elongate +
hairy +  and glabrous +
Crataegus sect. Aestivales +
Crataegus ×rufula +
Crataegus (sect. Coccineae) ser. Aestivales +
species +
3 cm30 mm <br />0.03 m <br /> (5 cm50 mm <br />0.05 m <br />) +
dark gray +  and black +
straight +
slender +  and stout +
1 cm10 mm <br />0.01 m <br /> (3 cm30 mm <br />0.03 m <br />) +
gland-tipped +
inconspicuous +
less erect +  and oblique +
1 +  and several +
determinate +
few +  and numerous +
2-5-flowered +
3 +  and 5 +
tree +  and shrub +