Crataegus aquacervensis

J. B. Phipps & O’Kennon

J. Bot. Res. Inst. Texas 1: 1061, plate 7.2c, fig. 11. 2007.

Common names: Elkwater hawthorn
Endemic
Treatment appears in FNA Volume 9. Treatment on page 506. Mentioned on page 504.

Shrubs, densely branched, 20–40 dm. Stems: twigs: new growth anthocyanin-rich, nearly glabrous, 1-year old medium to darker brown, older gray to dark gray; bark on 2–5 cm thick branches gray-brown; thorns on twigs usually recurved, ± stout, 3–6.5 cm, 2-years old dark redbrown. Leaves deciduous; petiole length 30–40% blade, hairy (only in adaxial sulcus), sessile-glandular; blade ovate or trullate-ovate to broadly elliptic, 3–3.5 cm at anthesis, 4–7 cm mature, ± coriaceous, base cuneate to broadly cuneate, lobes (2 or) 3 or 4 per side, pronounced, max LII 15–25%, lobe apex acute, margins serrate, teeth numerous, small, acute to subacute, veins (3 or) 4 or 5 per side, distinctly impressed adaxially, apex acute, shiny, abaxial surface glabrous, veins sometimes densely finely hairy along sides, adaxial ± densely appressed-scabrous hairy. Inflorescences 5–12-flowered; branches ± sparsely to moderately or densely pubescent; bracteoles light-brown, margins glandular. Flowers 15–18 mm diam.; hypanthium glabrate or sparsely to moderately pubescent; sepals pale with some anthocyanin or light-brown, triangular, 2.5 mm, margins denticulate to glandular-serrate, abaxially glabrous; stamens 10, anthers pale-pink or pink; styles 3 or 4. Fruiting pedicels glabrate or sparsely to moderately or densely hairy. Pomes reddish plum early (late Aug), dull purple mature (mid Sep), ellipsoid to broadly ellipsoid or ovoid, 10–12 mm diam., glabrate or moderately to densely pubescent; sepals usually erect-recurved, wide, 2.5–4 mm; pyrenes 3 or 4 (or 5), sides ± eroded, often shallowly.


Phenology: Flowering late May–early Jun; fruiting Aug–Sep.
Habitat: Thickets, light shade of Populus spp.
Elevation: 800–1200 m

Discussion

Crataegus aquacervensis is widely distributed in the northern part of the Cypress Hills westward from the Adams Creek area and Fort Walsh. The species is superficially similar to the sympatric C. rivuloadamensis (ser. Montaninsulae) and C. chrysocarpa (ser. Rotundifoliae), differing from both by the more or less eroded lateral faces of the pyrenes and from the latter by the larger, more venous leaves, prominent fruiting calyx, and ripe fruit color.

Selected References

None.

Lower Taxa

None.

"wide" is not a number.

... more about "Crataegus aquacervensis"
0.8 cm8 mm <br />0.008 m <br /> (2.5 cm25 mm <br />0.025 m <br />) +
pink +  and pale-pink +
James B. Phipps +
J. B. Phipps & O’Kennon +
exfoliating +  and plated +
2 cm20 mm <br />0.02 m <br /> (5 cm50 mm <br />0.05 m <br />) +
compound +  and simple +
opposite +  and alternate +
cuneate +  and broadly cuneate +
8 cm80 mm <br />0.08 m <br /> (12 cm120 mm <br />0.12 m <br />) +
trullate-ovate +  and broadly elliptic +
4 cm40 mm <br />0.04 m <br /> (7 cm70 mm <br />0.07 m <br />) +
adnate +  and distinct +
crowded +, scattered +  and alternate +
Elkwater hawthorn +
Alta. +  and Sask. +
not +  and aggregated +
800–1200 m +
1.5 cm15 mm <br />0.015 m <br /> (1.8 cm18 mm <br />0.018 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 to dark gray +  and darker brown +
older +, old +  and new +
Thickets, light shade of Populus spp. +
glabrate or +  and sparsely moderately pubescent +
constricted +
0.2 cm2 mm <br />0.002 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
crassinucellate +
deciduous +
pronounced +
light-brown +
denticulate +  and glandular-serrate +
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 +
glandular +  and eglandular +
hairy +  and glabrous +
1 cm10 mm <br />0.01 m <br /> (3 cm30 mm <br />0.03 m <br />) +
Flowering late May–early Jun +  and fruiting Aug–Sep. +
adnate +, free +, connate +  and distinct +
coriaceous-leaved +
dark gray-brown +  and russet +
exfoliating +  and corrugated +
reddish plum +
1 cm10 mm <br />0.01 m <br /> (1.2 cm12 mm <br />0.012 m <br />) +
glabrate or +  and moderately densely pubescent +
ellipsoid +  and broadly ellipsoid or ovoid +
J. Bot. Res. Inst. Texas +
not arillate +
0.25 cm2.5 mm <br />0.0025 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
persistent +
free +  and distinct +
erect-recurved +
triangular +
accrescent +
0.25 cm2.5 mm <br />0.0025 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
1-50-flowered +  and few-leaved +
shallow +  and deep +
free +  and distinct +
branched +  and simple +
persistent +
distinct +
exsert +  and lateral +
glabrate or +  and sparsely moderately or densely hairy +
elongate +
glabrous +  and tomentose +
Crataegus aquacervensis +
Crataegus (sect. Douglasia) ser. Purpureofructus +
species +
5 cm50 mm <br />0.05 m <br /> (7 cm70 mm <br />0.07 m <br />) +
dark redbrown +
straight +
slender +  and stout +
3 cm30 mm <br />0.03 m <br /> (6.5 cm65 mm <br />0.065 m <br />) +
craspedodromous +
acute +  and subacute +
inconspicuous +
1 +  and few +
straight +
determinate +
5 +  and 4 +