Cercocarpus betuloides var. betuloides

Illustrated
Synonyms: Cercocarpus betulifolius var. minor C. K. Schneider C. betuloides subsp. macrourus (Rydberg) A. E. Murray C. betuloides var. macrourus (Rydberg) Jepson C. douglasii Rafinesque C. macrourus Nuttall ex Hooker & Arnott C. minutiflorus Rydberg C. montanus var. glaber (S. Watson) F. L. Martin C. montanus var. macrourus (Rydberg) F. L. Martin C. montanus var. minutiflorus (Abrams) F. L. Martin C. parvifolius var. glaber S. Watson C. rotundifolius
Treatment appears in FNA Volume 9. Treatment on page 334. Mentioned on page 333, 335.

Shrubs or trees, 10–50 (–80) dm. Young stems sericeous or with ascending hairs. Leaves: stipules 1.5–5 (–5.7) mm; blade narrowly to broadly obovate or rhombic to broadly ovate, (9–) 15–30 (–70) × (5–) 10–18 (–52) mm, subcoriaceous to coriaceous, margins serrate or dentate to crenate in distal 1/2–2/3 (–3/4), abaxial veins usually sericeous or with ascending, rarely erect, hairs 0.2–0.5 mm, areoles canescent or some or all glabrous, adaxial surface mostly sericeous, or with ascending, erect hairs, or glabrate. Flowers 1–3 (–10) per short-shoot; hypanthial tubes sericeous or mixed sericeous with spreading hairs. Achenes 8–13.5 × 1.5–2.2 (–2.9) mm; fruiting pedicels (1.5–) 3–7 (–21) mm; hypanthial tubes (5–) 8–12 (–17) mm; pedicel/tube ratio (15–) 30–60 (–126) %; fruit awns (3.5–) 4.5–7.5 (–12.5) cm.


Phenology: Flowering Mar–May.
Habitat: Rocky slopes, outcrops, ravines, upper chaparral, oak woodlands, yellow pine forests
Elevation: (50–)150–1800(–2200) m

Distribution

V9 547-distribution-map.jpg

Ariz., Calif., Oreg., Mexico (Baja California)

Discussion

Variety betuloides extends from transmontane southern California (the dry eastern side of the coastal ranges) except in San Diego and Orange counties (where it incorporates the small-leaved Cercocarpus minutiflorus), onto the western slopes of the Sierra Nevada and to central-northern California from Santa Barbara County to southwestern Oregon, where it incorporates what has been recognized as var. macrourus, extending into central Arizona, and into Baja California, Mexico. Leaves are similar to those of plants in coastal southern California in mesic sites, but more narrowly obovate, thicker, more coriaceous, and cuneate-based in drier sites. The leaves are usually closely sericeous, less frequently the hairs are ascending to erect; they never have coiled hairs. The pedicels and hypanthial tubes can be sericeous throughout or with some to many spreading hairs. The plants also usually have few flowers per short-shoot cluster. Intermediates occur in zone of overlap with var. blancheae.

In Orange, Riverside, and San Diego counties of California, plants with small leaves, shorter stipules, and glabrous abaxial areoles have been recognized as Cercocarpus minutiflorus. Similar plants also occur from Santa Barbara to Trinity counties, many with small leaves, slightly longer stipules but with all (or only some) of the leaves with glabrous abaxial areoles indicating that the glabrous areole character is under developmental, not genetic, control, associated with thin, vernal leaves. Some leaves of var. blancheae also have glabrous areoles.

In Arizona, var. betuloides generally occurs at elevations below 1100(–1400) m, usually below populations of Cercocarpus breviflorus. In Arizona, var. betuloides is known from Gila, La Paz, Maricopa, Mojave, Pinal, and Yavapai counties; it can be distinguished by its silvery stems (versus red-brown in C. breviflorus) and spring versus late summer flowering.

Cercocarpus betulifolius Nuttall ex Hooker is an illegitimate name linked to this variety.

Selected References

None.

Lower Taxa

None.
villous +, pilose +  and sericeous +
with ascending , rarely erect , hairs +  and sericeous +
1.1 cm11 mm <br />0.011 m <br /> (1.35 cm13.5 mm <br />0.0135 m <br />) +
0.7 cm7 mm <br />0.007 m <br /> (2.1 cm21 mm <br />0.021 m <br />) +
0.22 cm2.2 mm <br />0.0022 m <br /> (0.29 cm2.9 mm <br />0.0029 m <br />) +
0.8 cm8 mm <br />0.008 m <br /> (1.35 cm13.5 mm <br />0.0135 m <br />) +
1.5mm +  and 2.2mm +
glabrate +  and sericeous +
0.1 cm1 mm <br />0.001 m <br /> (0.15 cm1.5 mm <br />0.0015 m <br />) +
glabrous +, some +  and canescent +
James Henrickson +  and Brian D. Vanden Heuvel +
Nuttall in J. Torrey and A. Gray +
maroon-brown +, silvery +  and dark gray or brownish black +
compound +  and simple +
opposite +  and alternate +
cordate +, cuneate +  and rounded +
3 cm30 mm <br />0.03 m <br /> (7 cm70 mm <br />0.07 m <br />) +
5 cm50 mm <br />0.05 m <br /> (7.8 cm78 mm <br />0.078 m <br />) +
1.8 cm18 mm <br />0.018 m <br /> (5.2 cm52 mm <br />0.052 m <br />) +
1.5 cm15 mm <br />0.015 m <br /> (3 cm30 mm <br />0.03 m <br />) +
rhombic +  and broadly ovate +
0.5 cm5 mm <br />0.005 m <br /> (5 cm50 mm <br />0.05 m <br />) +
? (?) +  and ? (?) +
10mm +  and 18mm +
free +  and distinct +
hemispheric-campanulate +
Ariz. +, Calif. +, Oreg. +  and Mexico (Baja California) +
not +  and aggregated +
(50–)150–1800(–2200) m +
eglandular +  and veined +
hairy +  and glabrous +
0.1 cm1 mm <br />0.001 m <br /> (1 cm10 mm <br />0.01 m <br />) +
0.6 cm6 mm <br />0.006 m <br /> (1.5 cm15 mm <br />0.015 m <br />) +
1 +  and 3 +
unisexual +  and bisexual +
not +  and aggregated +
7.5 cm75 mm <br />0.075 m <br /> (12.5 cm125 mm <br />0.125 m <br />) +
4.5 cm45 mm <br />0.045 m <br /> (7.5 cm75 mm <br />0.075 m <br />) +
1.1 cm11 mm <br />0.011 m <br /> (1.35 cm13.5 mm <br />0.0135 m <br />) +
cylindro-fusiform +
0.6 cm6 mm <br />0.006 m <br /> (1.1 cm11 mm <br />0.011 m <br />) +
chartaceous-coriaceous +
Rocky slopes, outcrops, ravines, upper chaparral, oak woodlands, yellow pine forests +
0.08 cm0.8 mm <br />8.0e-4 m <br /> (0.13 cm1.3 mm <br />0.0013 m <br />) +
spreading +, erect +  and ascending +
curled +  and wavy +
0.02 cm0.2 mm <br />2.0e-4 m <br /> (0.05 cm0.5 mm <br />5.0e-4 m <br />) +
0.2 cm2 mm <br />0.002 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
0.4 cm4 mm <br />0.004 m <br /> (0.7 cm7 mm <br />0.007 m <br />) +
1.2 cm12 mm <br />0.012 m <br /> (1.7 cm17 mm <br />0.017 m <br />) +
sericeous +  and mixed +
0.8 cm8 mm <br />0.008 m <br /> (1.2 cm12 mm <br />0.012 m <br />) +
villous +, hirsute-pilose +  and sericeous +
cinnamon brown +, tinged reddish +  and greenish yellow +
1-3(-18)-flowered +
crassinucellate +
drought-deciduous +  and persistent +
reduced +
flexuous +  and straight +
2 cm20 mm <br />0.02 m <br /> (5.5 cm55 mm <br />0.055 m <br />) +
glabrescent +  and hairy +
0.3 cm3 mm <br />0.003 m <br /> (2 cm20 mm <br />0.02 m <br />) +
dentate to crenate +  and serrate +
crenate +, flat +  and revolute +
inferior +  and superior +
clustered +, biseriate +  and superposed +
0 (?) +  and 4 (?) +
free +  and distinct +
5 +  and 4 +
0.9 cm9 mm <br />0.009 m <br /> (1.6 cm16 mm <br />0.016 m <br />) +
0.15 cm1.5 mm <br />0.0015 m <br /> (0.9 cm9 mm <br />0.009 m <br />) +
Flowering Mar–May. +
adnate +, free +, connate +  and distinct +
0.27 cm2.7 mm <br />0.0027 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
in J. Torrey and A. Gray, Fl. N. Amer. +
not arillate +
deciduous +
free +  and distinct +
erect +  and reflexed +
acute-acuminate +  and deltate +
0.1 cm1 mm <br />0.001 m <br /> (0.25 cm2.5 mm <br />0.0025 m <br />) +
not +  and branched +
3 cm30 mm <br />0.03 m <br /> (5.5 cm55 mm <br />0.055 m <br />) +
0.3 cm3 mm <br />0.003 m <br /> (3 cm30 mm <br />0.03 m <br />) +
0.1 cm1 mm <br />0.001 m <br /> (0.25 cm2.5 mm <br />0.0025 m <br />) +
Illustrated +
free +  and distinct +
1 +  and 20 +
0.5 cm5 mm <br />0.005 m <br /> (0.57 cm5.7 mm <br />0.0057 m <br />) +
adnate +  and free +
0.15 cm1.5 mm <br />0.0015 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
persistent +
distinct +
basal +, lateral +, subterminal +  and terminal +
elongate +
Cercocarpus betulifolius var. minor +, C. betuloides subsp. macrourus +, C. betuloides var. macrourus +, C. douglasii +, C. macrourus +, C. minutiflorus +, C. montanus var. glaber +, C. montanus var. macrourus +, C. montanus var. minutiflorus +, C. parvifolius var. glaber +  and C. rotundifolius +
Cercocarpus betuloides var. betuloides +
Cercocarpus betuloides +
variety +
inconspicuous +
hemispheric +
tree +  and shrub +