Crataegus okennonii

J. B. Phipps

Sida 18: 170, figs. 2, 4a–c, f. 1998.

Common names: O'Kennon hawthorn
Endemic
Treatment appears in FNA Volume 9. Treatment on page 513. Mentioned on page 494, 511, 514.

Shrubs or trees, 30–100 (–140) dm. Stems usually single-trunked; 1-year old twigs deep mahogany, shiny, older gray-brown; thorns on twigs single, slightly recurved, usually brown young, 2 cm. Leaves: (fall color plum to crimson or light crimson); petiole 1–2 cm, pubescence and glandularity not recorded; blade elliptic to broadly elliptic, sometimes ± narrowly ovate or rhombic, 4–6 cm, lobes 2 or 3 per side, lobe apex acute to ± obtuse, margins serrate, venation craspedodromous, veins 4 per side, apex subacute to obtuse, abaxial surface glabrous except on veins, adaxial finely appressed-pubescent. Inflorescences 12–20-flowered; branches glabrous, sometimes ± sparsely pubescent; bracteole margins stipitate-glandular. Flowers 15–20 mm diam.; hypanthium glabrous; sepals broadly triangular, 3 mm, margins obscurely glandular; stamens 10–12, anthers pale-pink; styles 3 or 4. Pomes red-burgundy to chestnut or reddish-brown (late Aug), deep purple to black at full maturity, ± ampulliform-orbicular, 8–10 mm diam., glabrous; sepal remnants reflexed, apex obtuse; pyrenes 3 or 4, sides ± eroded, sometimes plane. 2n = 68.


Phenology: Flowering May; fruiting Sep–Oct.
Habitat: Mesic thickets, natural hedgerows, scrub
Elevation: 300–700 m

Discussion

Crataegus okennonii is common in southern interior British Columbia and the eastern half of northern Washington, extending to Idaho and northwestern Montana, usually along streams or other water sources.

Although Crataegus okennonii is treated as a microspecies of C. douglasii by T. A. Dickinson et al. (2008), the ease with which most specimens can be identified and its relatively wide range merits taxonomic recognition. The plants are often distinctively tall, usually with a straight trunk.

While Crataegus okennonii fits towards an extreme of C. douglasii on individual characters, for example, relatively short thorns, broad, shallowly incised leaves, and larger flowers, the ensemble is unique. Further, putatively later anthesis, crimson fall foliage, and the peculiar color of the subripe fruit, red, reddish brown, or deep tan, are unknown for C. douglasii.

Selected References

None.

Lower Taxa

None.
... more about "Crataegus okennonii"
appressed-pubescent +
0.8 cm8 mm <br />0.008 m <br /> (2.5 cm25 mm <br />0.025 m <br />) +
James B. Phipps +
J. B. Phipps +
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 +
elliptic +  and elliptic to broadly +
5 cm50 mm <br />0.05 m <br /> (8 cm80 mm <br />0.08 m <br />) +
rhombic +  and ovate +
4 cm40 mm <br />0.04 m <br /> (6 cm60 mm <br />0.06 m <br />) +
? (?) +  and ? (?) +
stipitate-glandular +
orange +  and dark gray-brown +
pubescent +  and glabrous +
adnate +  and distinct +
crowded +, scattered +  and alternate +
O'Kennon hawthorn +
B.C. +, Idaho +, Mont. +  and Wash. +
not +  and aggregated +
300–700 m +
1.5 cm15 mm <br />0.015 m <br /> (2 cm20 mm <br />0.02 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 />) +
usually tan +  and deep mahogany +
pubescent +  and glabrous +
Mesic thickets, natural hedgerows, scrub +
constricted +
0.2 cm2 mm <br />0.002 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
crassinucellate +
deciduous +
obscure +  and evident +
craspedodromous +
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 +
glandular +  and eglandular +
1.5 cm15 mm <br />0.015 m <br /> (2.2 cm22 mm <br />0.022 m <br />) +
pubescent +  and glabrous +
1 cm10 mm <br />0.01 m <br /> (2 cm20 mm <br />0.02 m <br />) +
Flowering May +  and fruiting Sep–Oct. +
adnate +, free +, connate +  and distinct +
dark gray-brown +  and russet +
exfoliating +  and corrugated +
red-burgundy +  and chestnut or reddish-brown deep purple +
0.8 cm8 mm <br />0.008 m <br /> (1 cm10 mm <br />0.01 m <br />) +
ampulliform-orbicular +
not arillate +
0.4 cm4 mm <br />0.004 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
persistent +
free +  and distinct +
patent-recurved +  and reflexed +
triangular +
3 cm30 mm <br />0.03 m <br /> (?) +
1-50-flowered +  and few-leaved +
free +  and distinct +
single-trunked +
persistent +
distinct +
exsert +  and lateral +
elongate +
glabrous +  and tomentose +
Crataegus okennonii +
Crataegus (sect. Douglasia) ser. Douglasianae +
species +
craspedodromous +
6 cm60 mm <br />0.06 m <br /> (10 cm100 mm <br />0.1 m <br />) +
straight +
slender +  and stout +
2 cm20 mm <br />0.02 m <br /> (?) +
craspedodromous +  and gland-tipped +
inconspicuous +
1 +  and few +
gray-brown +  and mahogany +
determinate +
older +  and old +
tree +  and shrub +