Ivesia lycopodioides |
Ivesia sericoleuca |
|||||||||
---|---|---|---|---|---|---|---|---|---|---|
club-moss ivesia, clubmoss mousetail |
Plumas ivesia, Plumas mousetail |
|||||||||
Habit | Plants green, usually rosetted, sometimes ± tufted; taproot fusiform, fleshy. | Plants silvery to grayish green; glands usually sparse, sometimes abundant. | ||||||||
Stems | decumbent to erect, 0.3–3 dm. |
decumbent to ascending, 1.5–4.5 dm. |
||||||||
Basal leaves | tightly to loosely cylindric, 1–15 cm; sheathing base glabrous abaxially; petiole 0.5–4 cm, hairs 0.2–1 mm; leaflets 10–35 per side, 1–8 mm, glabrous or short-hirsute, minutely glandular, lobes (2–)4–8(–10), linear to obovate or ± orbiculate, apex sometimes setose. |
10–20(–30) cm; sheathing base densely strigose abaxially; stipules absent; petiole 2–6(–10) cm, hairs abundant, usually spreading, 1–4 mm; leaflets 20–35 per side, loosely overlapping, 3–15 mm, lobes 0–4, oblanceolate to elliptic, hairs abundant, spreading to ascending, (0.5–)1–3(–4) mm. |
||||||||
Cauline leaves | 0–2(–3), not paired. |
3–8(–10). |
||||||||
Inflorescences | 3–20(–25)-flowered, (0.5–)1–2.5(–3.5) cm diam.; glomerules usually 1. |
20–120-flowered, (2–)4–14 cm diam., flowers mostly arranged in several to many tight glomerules of 5–10 flowers. |
||||||||
Pedicels | (0.5–)1–7(–11) mm. |
1–3(–12) mm. |
||||||||
Flowers | 6–12 mm diam.; epicalyx bractlets oblong to oval, 0.8–2.5(–3) mm; hypanthium shallowly cupulate, 1–2 × 2.5–5 mm; sepals (1.8–)2–4(–4.5) mm, obtuse to acute; petals golden yellow, obovate, 2–5 mm; stamens 5, filaments 0.8–2 mm, anthers yellow, 0.6–0.8 mm; carpels (5–)8–15(–18), styles 1–3 mm. |
10–15 mm diam.; epicalyx bractlets narrowly lanceolate to narrowly elliptic, (1.5–)2–2.5(–3) mm; hypanthium campanulate to shallowly turbinate, 1.5–3 × 2.5–4.5(–5) mm, often nearly as deep as wide; sepals sometimes purple-suffused, 3–5.5 mm, acute to acuminate; petals white, broadly spatulate to broadly obovate or obcordate, 4–7 mm; stamens 20, filaments filiform, 1.5–3 mm, anthers white to cream, 0.5–0.7 mm; carpels 2–7, styles 2.5–4 mm. |
||||||||
Achenes | greenish tan to light brown, 1.2–1.5 mm. |
brown, 2–3 mm. |
||||||||
2n | = 28. |
|||||||||
Ivesia lycopodioides |
Ivesia sericoleuca |
|||||||||
Phenology | Flowering summer. | |||||||||
Habitat | Dry gravelly meadows, margins of seeps, usually on vernally saturated volcanic soil, in sagebrush and grass communities, conifer woodlands | |||||||||
Elevation | 1300–2300 m (4300–7500 ft) | |||||||||
Distribution |
CA; NV
|
CA
|
||||||||
Discussion | Varieties 3 (3 in the flora). The three varieties of Ivesia lycopodioides are for the most part readily distinguished, though intergradation is known. The high-elevation var. lycopodioides extends farthest north; var. scandularis is the only variety in the White Mountains. Variety megalopetala is found mostly at somewhat lower (subalpine) elevations and generally has a more southern range. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Of conservation concern. Ivesia sericoleuca is known from valleys and flats in the northern Sierra Nevada. Many historic collections were identified and distributed as I. unguiculata, and circumscriptions prior to 1962 include I. aperta (hence reports from Nevada). Hairs are usually dense in plants of Ivesia sericoleuca, such that the leaves, and occasionally the stems and branches, are silvery gray, especially in Sierra Valley and the Feather River drainage. Plants in the Truckee River drainage tend to be less hairy with redder stems, less glomerate inflorescences, shallower hypanthia, and more conspicuous glandularity. As mentioned by J. T. Howell (1962), the chromosome count given for Ivesia sericoleuca by P. A. Munz (1959) most likely was based on a collection of I. aperta var. aperta. The chromosome count given here is instead based on Kruckeberg 3665, originally distributed as I. pickeringii. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
||||||||
Key |
|
|||||||||
Source | FNA vol. 9, p. 232. | FNA vol. 9, p. 240. | ||||||||
Parent taxa | Rosaceae > subfam. Rosoideae > tribe Potentilleae > Ivesia > sect. Ivesia | Rosaceae > subfam. Rosoideae > tribe Potentilleae > Ivesia > sect. Unguiculatae | ||||||||
Sibling taxa | ||||||||||
Subordinate taxa | ||||||||||
Synonyms | Potentilla lycopodioides | Horkelia sericoleuca, Potentilla sericoleuca | ||||||||
Name authority | A. Gray: Proc. Amer. Acad. Arts 6: 530. (1865) | (Rydberg) Rydberg: in N. L. Britton et al., N. Amer. Fl. 22: 284. (1908) | ||||||||
Web links |