Crataegus sheridana

A. Nelson

Bot. Gaz. 34: 370. 1902.

Common names: Great Plains hawthorn
Endemic
Treatment appears in FNA Volume 9. Treatment on page 521. Mentioned on page 516, 517.

Shrubs, 20–35 dm. Stems: twigs: new growth color not recorded, pubescent, 1-year old light-brown to olive-tan or mid brown, 2-years old dark gray or reddish-brown overlaid dark gray, older gray; thorns on twigs usually numerous, usually recurved, 2-years old very dark, shiny redbrown, slender to moderately thick, (2.5–) 3–5 (–7) cm. Leaves: petiole length 40–50% blade, pubescent (especially in adaxial sulcus), ± densely sessile-glandular; blade sometimes broadly ovate or suborbiculate, sometimes ± ovate, elliptic-ovate to ovate, 3.5–5 (–6) cm, nearly full grown at flowering, ± thin, base cuneate, broadly cuneate, or subtruncate to subcordate, lobes (3 or) 4 (or 5) per side, sinuses shallow, LII 5–15%, lobe apex acute (except where blades elliptic-ovate to ovate, then lobes deeper, LII 15–30%, lobe apex subacute), margins with subacute teeth, veins 3 or 4 per side, apex acute to obtuse, abaxial surface glabrous, veins glabrous or pubescent young, adaxial densely appressed-scabrous-pubescent young (variably persistent). Inflorescences 5–15-flowered; branches ± densely pubescent; bracteoles pallid, narrow, margins sessile-glandular. Flowers 14–16 mm diam.; hypanthium proximally ± tomentose, medially densely short-pubescent; sepals greenish, triangular, length not recorded, margins glandular-serrate, abaxially glabrous, adaxially pubescent; stamens 10, anthers ivory; styles 4 or 5. Pomes 1–6 in infructescences, bright red, broadly ellipsoid to suborbicular, 9–11 mm tall, pubescent, rarely glabrate; sepals ± spreading to reflexed; pyrenes 3 or 4, sides ± roughened with shallow, irregular pitting or diagonal scarring.


Phenology: Flowering May–Jun; fruiting Sep.
Habitat: Thickets, brush
Elevation: 300–1200 m

Distribution

V9 881-distribution-map.jpg

Alta., Sask., Minn., Mont., N.Dak., S.Dak., Wyo.

Discussion

Crataegus sheridana occurs only east of the Rocky Mountains and is abundant in the Cypress Hills of Alberta and Saskatchewan. Collections from the montane islands of Montana are also known. Until confusion with the superficially similar C. chrysocarpa of the Great Plains and Prairies is cleared up in all the relevant herbaria, we will have an incomplete knowledge of the distribution of C. sheridana; however, it is widespread in the Great Plains region. Its plants are usually taller than sympatric C. chrysocarpa and also C. macracantha.

Crataegus sheridana has superficial resemblances to the C. chrysocarpa group; it is distinguished by its pitted pyrenes and usually larger leaves. In the Cypress Hills, where this species has the shortest thorns of any hawthorn in the red-fruited group, it is further distinguished from most specimens of the C. chrysocarpa group by the densely hairy to tomentose inflorescence branches and hypanthia and by its leaf shape. Collections from the Cypress Hills indicate that form of C. sheridana to be peculiarly round-leaved with pallid bracteoles; Montana forms have longer thorns, longer, more acutely lobed leaves, more elliptic-ovate to ovate blades, and red-brown rather than pallid bracteoles.

In all likelihood, Crataegus sheridana represents a series of hybrid descendants between C. chrysocarpa and C. macracantha. The reasons for ignoring its existence over a long period were discussed by J. B. Phipps et al. (2007).

Selected References

None.

Lower Taxa

None.
... more about "Crataegus sheridana"
appressed-scabrous-pubescent +
0.8 cm8 mm <br />0.008 m <br /> (2.5 cm25 mm <br />0.025 m <br />) +
James B. Phipps +
A. Nelson +
compound +  and simple +
opposite +  and alternate +
subtruncate +  and subcordate +
Crataegus sect. Macracanthae +
less ovate or rhombic-elliptic +  and rhombic-elliptic +
5 cm50 mm <br />0.05 m <br /> (6 cm60 mm <br />0.06 m <br />) +
elliptic-ovate +  and ovate +
3.5 cm35 mm <br />0.035 m <br /> (5 cm50 mm <br />0.05 m <br />) +
adnate +  and distinct +
crowded +, scattered +  and alternate +
Great Plains hawthorn +
Alta. +, Sask. +, Minn. +, Mont. +, N.Dak. +, S.Dak. +  and Wyo. +
not +  and aggregated +
300–1200 m +
1.4 cm14 mm <br />0.014 m <br /> (1.6 cm16 mm <br />0.016 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 +, reddish-brown overlaid dark gray +, dark gray +, old +, brown +, light-brown +  and olive-tan +
older +  and new +
tomentose +  and glabrous +
Thickets, brush +
short-pubescent +  and tomentose +
constricted +
0.2 cm2 mm <br />0.002 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
crassinucellate +
deciduous +
craspedodromous +
entire +  and serrate +
not glandular-serrate +
pubescent +  and glabrous +
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 +
eglandular +  and glandular +
pubescent +
Flowering May–Jun +  and fruiting Sep. +
adnate +, free +, connate +  and distinct +
dark gray-brown +  and russet +
exfoliating +  and corrugated +
bright red +
0.9 cm9 mm <br />0.009 m <br /> (1.1 cm11 mm <br />0.011 m <br />) +
glabrate +  and pubescent +
broadly ellipsoid +  and suborbicular +
not arillate +
persistent +
free +  and distinct +
glandular-denticulate +  and glandular-laciniate +
less spreading +  and reflexed +
triangular +
1-50-flowered +  and few-leaved +
eroded +  and pitted +
free +  and distinct +
branched +  and simple +
persistent +
distinct +
exsert +  and lateral +
elongate +
glabrous +  and tomentose +
Crataegus sheridana +
Crataegus (sect. Macracanthae) ser. Macracanthae +
species +
5 cm50 mm <br />0.05 m <br /> (7 cm70 mm <br />0.07 m <br />) +
redbrown +  and dark +
slender +
3 cm30 mm <br />0.03 m <br /> (5 cm50 mm <br />0.05 m <br />) +
craspedodromous +  and gland-tipped +
subacute +
inconspicuous +
less erect +  and oblique +
1 +  and several +
determinate +
pubescent +  and glabrous +
4 +  and 3 +