Adenostoma

Hooker & Arnott

Bot. Beechey Voy., 139. 1832.

Common names: Chamise
Etymology: Greek a den, gland, and stoma, mouth, alluding to gland at rim of hypanthium
Treatment appears in FNA Volume 9. Treatment on page 392. Mentioned on page 393, 395.
 TaxonIllustrator 
FNA9 P33 Coleogyne ramosissima.jpegColeogyne ramosissima
Adenostoma fasciculatum var. fasciculatum
Chamaebatiaria millefolium
Marjorie C. Leggitt
Marjorie C. Leggitt
Marjorie C. Leggitt

Shrubs, erect to rounded-spreading, 8–60 dm; developing enlarged woody lignotubers. Stems 1–10+, erect to arching or spreading, branched, terete or decurrently grooved; bark of red brownish papery layers, weathering gray; short-shoots present or absent; hirtellous, pilose, or glabrous. Leaves persistent, cauline, alternate, sometimes opposite, juvenile 1–2-pinnatifid, mature simple; stipules reduced or absent; petiole present or absent; blade linear to terete or linear-oblanceoloid, (0.2–) 0.3–1.4 (–2.6) mm, leathery or not, base persistent, clasping, truncate, margins revolute, entire, abaxial surface glabrous or sessile-glandular. Inflorescences terminal, 2–400+-flowered, panicles well branched, pyramidal or racemes or spikes reduced to cylindric, glabrous or hirtellous; bracts present; bracteoles present. Pedicels absent or relatively short. Flowers 2–6 mm diam.; hypanthium cylindric to campanulate, inner rim annular gland thickened, undulate, 0.6–2.4 mm, glabrous or hirtellous; sepals 5, erect to reflexed, valvate, broadly ovate to semiorbiculate; petals 5, white becoming rusty brown, obovate-orbiculate or elliptic to ovate, base clawed; stamens 10 or 15 in groups of 2 or 3 alternate with petals, shorter than petals; carpels 1 (or 2), distinct, obliquely truncate distally, glabrous or sericeous, styles lateral, each bending over ovary, erect distally, stigmas capitate to truncate; ovules 1 (or 2). Fruits achenes, 1 (or 2), obovoid or ellipsoid, 1.1–1.8 (–2.4) mm, hirtellous distally (exposed part); hypanthium persistent; sepals persistent, moreorless spreading; styles not persistent. x = 9.

Distribution

Calif., nw Mexico

Discussion

Species 2 (2 in the flora).

Adenostoma is a Madro-Tertiary derivative of a lineage with compound leaves. Seedlings and sucker shoots have 1–2-pinnatifid leaves; mature leaves are simple, undivided. Both species occur in chaparral and resprout after fires from basal lignotubers. The single achenes are derived from ancestral 5-follicled fruits, each carpel retaining the ancestral marginal style. Stamens are arranged in groups of 2 to 3 alternate with petals; filaments expand sequentially, first 5 (1 opposite each sepal), followed by the second 5 and third 5 (when 15).

Selected References

None.

Key

1 Leaves crowded on short shoots, blades dark green, adaxial surfaces glabrous; stipules present on long-shoot leaves; subtending flower bracts 3-lobed, medial lobe largest; bracteoles 2, subulate; stamens (10–)15. Adenostoma fasciculatum
1 Leaves on slender long shoots (short-shoot fascicles absent), blades yellow-green, adaxial surfaces sparsely hirtellous and sessile-glandular; stipules absent; subtending flower bracts linear-subulate; bracteoles 5 or 6, outermost subulate, inner oblong-obovate; stamens 10(–12). Adenostoma sparsifolium
... more about "Adenostoma"
sessile-glandular +  and glabrous +
William Jones +  and James Henrickson +
Hooker & Arnott +
compound +  and simple +
opposite +  and alternate +
persistent +
0.14 cm1.4 mm <br />0.0014 m <br /> (0.26 cm2.6 mm <br />0.0026 m <br />) +
linear +  and terete or linear-oblanceoloid +
0.03 cm0.3 mm <br />3.0e-4 m <br /> (0.14 cm1.4 mm <br />0.0014 m <br />) +
Not (?) +  and Leathery (?) +
sericeous +  and glabrous +
opposite +  and alternate +
mature +  and juvenile +
1-2-pinnatifid +
Chamise +
Calif. +  and nw Mexico +
not +  and aggregated +
Greek a den, gland, and stoma, mouth, alluding to gland at rim of hypanthium +
0.2 cm2 mm <br />0.002 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
unisexual +  and bisexual +
not +  and aggregated +
not +  and aggregated +
0.18 cm1.8 mm <br />0.0018 m <br /> (0.24 cm2.4 mm <br />0.0024 m <br />) +
ellipsoid +  and obovoid +
0.11 cm1.1 mm <br />0.0011 m <br /> (0.18 cm1.8 mm <br />0.0018 m <br />) +
hirtellous +  and glabrous +
undulate +  and annular +
0.06 cm0.6 mm <br />6.0e-4 m <br /> (0.24 cm2.4 mm <br />0.0024 m <br />) +
crassinucellate +
red brownish +
opposite +  and alternate +
persistent +
toothed +, unlobed +  and lobed +
inferior +  and superior +
biseriate +  and clustered +
collateral +  and basal +
pyramidal +
0 (?) +  and 4 (?) +
free +  and distinct +
adnate +, free +, connate +  and distinct +
Bot. Beechey Voy., +
hirtellous +  and glabrous +
cylindric +
reduced +
not arillate +
persistent +
free +  and distinct +
spreading +, erect +  and reflexed +
broadly ovate +  and semiorbiculate +
glabrous +, pilose +  and hirtellous +
hirtellous +  and glabrous +
cylindric +
reduced +
free +  and distinct +
grooved +  and branched +
erect +  and arching or spreading +
1 +  and 10 +
capitate +  and truncate +
adnate +  and free +
not persistent +
distinct +
erect +  and bending +
not elongate +
Adenostoma +
Rosaceae tribe Sorbarieae +
inconspicuous +
erect +  and rounded-spreading +