Holodiscus discolor var. discolor

Illustrated
Synonyms: Holodiscus australis A. Heller H. boursieri (Carrière) Rehder H. discolor var. delnortensis F. A. Ley H. discolor var. franciscanus (Rydberg) Jepson H. dumosus var. australis (A. Heller) F. A. Ley H. dumosus subsp. saxicola (A. Heller) Abrams Spiraea ariifolia
Treatment appears in FNA Volume 9. Treatment on page 418. Mentioned on page 419.

Stems 1–6 m. Leaves: long-shoots (predominant): petiole distinct, rarely with decurrent blades; blade broadly trullate or ovate to slightly rhombic, maximal width usually in proximal 1/4 of blade, 2–10 × 1–8 cm, base obtuse and truncate, sometimes to slightly acute, apex obtuse; short-shoots (absent or not predominant): petiole usually distinct, blade ovate to slightly rhombic, maximal width proximal to midpoint, 2–8 × 1–7 cm, base obtuse and truncate, sometimes acute, margins usually with secondary teeth, apex obtuse. Inflorescences (2–) 4–20 × (2–) 4–15 cm, multibranched, dense. 2n = 36.


Phenology: Flowering Apr–Aug.
Habitat: Open woodlands, forest edges, thickets, dry to moist, often partially shaded, rocky slopes
Elevation: 0–3000 m

Distribution

V9 704-distribution-map.jpg

B.C., Ariz., Calif., Colo., Idaho, Mont., Nev., N.Mex., Oreg., Tex., Utah, Wash., Wyo., Mexico (Baja California), Mexico (Chihuahua), Mexico (Distrito Federal), Mexico (Durango), Mexico (Guanajuato), Mexico (Nuevo León), Mexico (Querétaro), Mexico (San Luis Potosí), Mexico (Sonora), Mexico (Zacatecas)

Discussion

As treated here, var. discolor covers wide elevational and latitudinal ranges and displays significant variation. The variety includes populations that might best be segregated to produce a classification within the species that would more precisely reflect the morphologic, ecologic, and geographic patterns observed. In a detailed study of leaf variation and carpel morphology in northeastern Oregon and Washington, C. J. Antieau (1985) found that: phenotype is a reliable indicator of general patterns of genetic divergence; for the characters examined, inherent variation was non-random; and, morphologies observed in field collections were being maintained in cultivation. Although the study by Antieau was on a restricted region of the range of Holodiscus discolor, his observations may be applicable to the species as a whole; infraspecific taxa with consistent phenotypic expressions and genetic bases might be segregated after further study.

Selected References

None.

Lower Taxa

None.
glabrate +  and densely tomentose or villous +
beige +  and white +
stipitate-glandular +, hirsute +  and hispid +
0.1 cm1 mm <br />0.001 m <br /> (0.15 cm1.5 mm <br />0.0015 m <br />) +
glabrate +  and thinly puberulent +
0.5 cm5 mm <br />0.005 m <br /> (1 cm10 mm <br />0.01 m <br />) +
1 cm10 mm <br />0.01 m <br /> (8 cm80 mm <br />0.08 m <br />) +
abaxially puberulent +  and tomentulose +
1cm +  and 7cm +
Richard Lis +
(Pursh) Maximowicz +
light to dark gray +
exfoliating +
compound +  and simple +
opposite +  and alternate +
acute +  and obtuse +
Spiraea discolor +
3 cm30 mm <br />0.03 m <br /> (4 cm40 mm <br />0.04 m <br />) +
2 cm20 mm <br />0.02 m <br /> (8 cm80 mm <br />0.08 m <br />) +
proximal +  and midpoint +
ovate +  and slightly rhombic +
1 cm10 mm <br />0.01 m <br /> (10 cm100 mm <br />0.1 m <br />) +
? (?) +  and ? (?) +
1cm +  and 7cm +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (0.15 cm1.5 mm <br />0.0015 m <br />) +
glabrate +, usually tomentose +  and villous +
hispid +  and hirsute +
0.1 cm1 mm <br />0.001 m <br /> (0.15 cm1.5 mm <br />0.0015 m <br />) +
B.C. +, Ariz. +, Calif. +, Colo. +, Idaho +, Mont. +, Nev. +, N.Mex. +, Oreg. +, Tex. +, Utah +, Wash. +, Wyo. +, Mexico (Baja California) +, Mexico (Chihuahua) +, Mexico (Distrito Federal) +, Mexico (Durango) +, Mexico (Guanajuato) +, Mexico (Nuevo León) +, Mexico (Querétaro) +, Mexico (San Luis Potosí) +, Mexico (Sonora) +  and Mexico (Zacatecas) +
not +  and aggregated +
0–3000 m +
exfoliating +
puberulent +  and tomentose +
0.2 cm2 mm <br />0.002 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
unisexual +  and bisexual +
dolabriform +  and flattened +
not +  and aggregated +
not +  and aggregated +
stipitate +  and sessile +
Open woodlands, forest edges, thickets, dry to moist, often partially shaded, rocky slopes +
sessile-glandular +  and stipitate +
white +, tan +  and golden +
0.3 cm3 mm <br />0.003 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
2 cm20 mm <br />0.02 m <br /> (4 cm40 mm <br />0.04 m <br />) +
2 cm20 mm <br />0.02 m <br /> (4 cm40 mm <br />0.04 m <br />) +
4cm +  and 20cm +
pendulous +  and erect +
4cm +  and 15cm +
crassinucellate +
compound +  and simple +
deciduous +
4 cm40 mm <br />0.04 m <br /> (10 cm100 mm <br />0.1 m <br />) +
pleated +  and angled +
10 cm100 mm <br />0.1 m <br /> (200 cm2,000 mm <br />2 m <br />) +
simple-craspedodromous +
toothed +, unlobed +  and lobed +
inferior +  and superior +
biseriate +  and clustered +
collateral +  and apical +
tomentose +, villous +, puberulent +  and glabrate +
reddish +  and maroon +
0 (?) +  and 4 (?) +
free +  and distinct +
0.15 cm1.5 mm <br />0.0015 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
0.5 cm5 mm <br />0.005 m <br /> (3 cm30 mm <br />0.03 m <br />) +
Flowering Apr–Aug. +
adnate +, free +, connate +  and distinct +
Trudy Imp. S.-Peterburgsk. Bot. Sada +
0.1 cm1 mm <br />0.001 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
not arillate +
persistent +
free +  and distinct +
erect +  and spreading or slightly reflexed +
triangular-ovate +  and elliptic-ovate +
0.1 cm1 mm <br />0.001 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
pilose-tomentose +, canescent +, downy +, glabrate +  and glabrous +
pleated +, angled +  and long +
0.5 cm5 mm <br />0.005 m <br /> (2 cm20 mm <br />0.02 m <br />) +
Illustrated +
free +  and distinct +
2mm +  and 3.5mm +
branched +  and simple +
erect +  and arching +
1 +  and 10 +
100 cm1,000 mm <br />1 m <br /> (600 cm6,000 mm <br />6 m <br />) +
persistent +  and deciduous +
distinct +
basal +, lateral +, subterminal +  and terminal +
not elongate +
Holodiscus australis +, H. boursieri +, H. discolor var. delnortensis +, H. discolor var. franciscanus +, H. dumosus var. australis +, H. dumosus subsp. saxicola +  and Spiraea ariifolia +
Holodiscus discolor var. discolor +
Holodiscus discolor +
variety +
inconspicuous +
thickened +  and minute +
20 cm200 mm <br />0.2 m <br /> (150 cm1,500 mm <br />1.5 m <br />) +
erect +  and arching +