Adenostoma fasciculatum

Hooker & Arnott

Bot. Beechey Voy., 139. 1832.

Common names: Greasewood
Illustrated
Treatment appears in FNA Volume 9. Treatment on page 393.
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Plants decumbent or erect-ascending, 8–20 dm. Stems erect to arching; young stem internodes brown, 2–6.5(–12) mm, glabrous or hirtellous-pilose, rarely glandular. Leaves crowded on short shoots; stipules green, 0.5–1.5 mm on long-shoot leaves, smaller on fascicled leaves; blade dark green, linear-oblanceolate, (2–)3–10(–13) × 0.6–1(–1.7) mm, apex acute, apiculate to obtuse, abaxial surface glabrous or hirtellous or villous, adaxial glabrous. Inflorescences of alternately branched pyramidal panicles, 3.5–10(–17) × 1–9(–15) cm or reduced to cylindric racemes or spikes, glabrous; subtending flower bracts 3-lobed, medial lobe largest; bracteoles 2, subulate. Pedicels present, short. Flowers in clusters of 1–3(–7); hypanthium green, 1.5–2.4 × 1–1.6(–2) mm, obscurely 10-veined, conspicuously so when dry, glabrous or weakly hirtellous, inner rims whitish; sepals broadly ovate to semiorbiculate, 0.5–0.9 mm; petals tardily falling, white, turning rusty, obovate-orbiculate, to 1–2 mm diam.; stamens (10–)15, filaments 1–1.5 mm, anthers 0.4–0.8 mm; ovaries obconic; styles curved over ovary, erect distally, white, rarely pinkish distally, 1–1.4 mm. Achenes obovoid, 1.2–1.8(–2.4) mm, contained within hypanthium.

Discussion

Varieties 3 (3 in the flora).

Selected References

None.

Key

1 Stems decumbent (plants low, mounded); insular. Adenostoma fasciculatum var. prostratum
1 Stems erect-ascending, spreading (plants tall); mainland and insular > 2
2 Young stems glabrous, sometimes +/- hirtellous; leaves oblanceolate to linear, (2.5–)5–13 mm, apices acute-apiculate. Adenostoma fasciculatum var. fasciculatum
2 Young stems pubescent to villous; leaves oblanceolate-clavate, 4–6.5 mm, apices usually obtuse. Adenostoma fasciculatum var. obtusifolium