Crataegus nananixonii

J. B. Phipps & O’Kennon

Sida 17: 569, fig. 1. 1997.

Common names: Nixon’s dwarf hawthorn
Endemic
Treatment appears in FNA Volume 9. Treatment on page 590. Mentioned on page 586.

Shrubs, 10–15 dm. Stems intricately branched; twigs: new growth reddish green, pubescent, 1-year old gray to gray-brown, older gray; thorns on twigs straight to slightly recurved, 2-years old dark dull gray, fine, 1–3 cm. Leaves: petiole length 20–40% blade, pubescence not recorded, gland-dotted; blade rhombic-ovate, 1.5–3.5 cm, base broadly cuneate, lobes 0 or with sinuses very shallow, margins ± irregularly serrate, some teeth gland-tipped, especially proximally, veins 3 per side, apex acute, abaxial surface glabrous, veins sparsely pubescent, adaxial sparsely scabrous young, glabrescent. Inflorescences 3–5-flowered; branches pubescent; bracteole margins short-stipitate-glandular. Flowers 12–15 mm diam.; hypanthium glabrous; sepals lanceolate, 4–5 mm, margins glandular, abaxially glabrous; petals slightly clawed; stamens 10, anthers rose-purple; styles 3–5. Pomes coppery red, suborbicular, 10 mm diam., glabrous; sepal remnants present or not, on collar, patent-reflexed; pyrenes 3–5.


Phenology: Flowering Apr; fruiting Sep–Oct.
Habitat: Open sandy sites
Elevation: 200 m

Discussion

Crataegus nananixonii is restricted to open sandy sites in Nacogdoches and nearby counties of eastern Texas. The species is a very dwarf and distinctive member of ser. Intricatae, similar to C. biltmoreana but with much smaller parts.

Selected References

None.

Lower Taxa

None.

"thin" is not a number."pubescence" is not a number."adnate" is not a number."dm" is not declared as a valid unit of measurement for this property.

... more about "Crataegus nananixonii"
0.8 cm8 mm <br />0.008 m <br /> (2.5 cm25 mm <br />0.025 m <br />) +
rose-purple +
James B. Phipps +
J. B. Phipps & O’Kennon +
orangebrown +
thin-exfoliating +  and corrugated +
compound +  and simple +
opposite +  and alternate +
cuneate +
Intricatae +
6 cm60 mm <br />0.06 m <br /> (9 cm90 mm <br />0.09 m <br />) +
rhombic-ovate +
1.5 cm15 mm <br />0.015 m <br /> (3.5 cm35 mm <br />0.035 m <br />) +
coriaceous +
short-stipitate-glandular +
adnate +  and distinct +
crowded +, scattered +  and alternate +
Nixon’s dwarf hawthorn +
not +  and aggregated +
less hard +  and mealy +
1.2 cm12 mm <br />0.012 m <br /> (1.5 cm15 mm <br />0.015 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 +  and gray-brown +
older +  and new +
Open sandy sites +
constricted +
crassinucellate +
deciduous +
craspedodromous +
glandular-serrate +  and glandular-pectinate +
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 (?) +
pale paper brown +
free +  and distinct +
post-mature +
stipitate +  and sessile +
gland-dotted +
Flowering Apr +  and fruiting Sep–Oct. +
adnate +, free +, connate +  and distinct +
dark gray-brown +  and russet +
exfoliating +  and corrugated +
pruinose +
coppery red +
10 cm100 mm <br />0.1 m <br /> (?) +
suborbicular +
not arillate +
persistent +
free +  and distinct +
patent +  and reflexed +
lanceolate +
nonaccrescent +
0.4 cm4 mm <br />0.004 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
1-50-flowered +  and few-leaved +
free +  and distinct +
persistent +
distinct +
exsert +  and lateral +
elongate +
pubescent +  and glabrous +
Crataegus sect. Flavae +  and Crataegus ser. +
Crataegus nananixonii +
Crataegus (sect. Coccineae) ser. Intricatae +
species +
4 cm40 mm <br />0.04 m <br /> (6 cm60 mm <br />0.06 m <br />) +
gray +  and dark +
straight +
slender +
1 cm10 mm <br />0.01 m <br /> (3 cm30 mm <br />0.03 m <br />) +
gland-tipped +
inconspicuous +
buff to gray-brown +  and corrugated +
less erect +  and oblique +
1 +  and several +
straight +
determinate +