Ivesia lycopodioides var. lycopodioides
Ivesia sect. Ivesia
clubmoss ivesia, clubmoss mousetail
decumbent to ascending, 0.3–1(–1.5) dm.
(0.2–)0.3–2(–4) dm.
1–7 cm;
leaflets tightly overlapping, glabrous or sparsely short-hirsute, lobes ± orbiculate, ± 1 mm, apical setae 0(–0.5) mm.
usually loosely to very tightly cylindric (mousetail-like in I. muirii), rarely weakly planar (I. longibracteata);
stipules present;
leaflets overlapping, individually distinguishable or not, lobed to base, sparsely to densely hairy, sometimes glabrous or glabrate;
terminal leaflets indistinct.
0–1.
(0–)1–3, sometimes paired;
blade usually ± reduced to vestigial, rarely well developed.
usually ± capitate, 3–15(–20)-flowered, 0.5–1.5(–2) cm diam.
usually ± congested, sometimes becoming open in fruit, flowers mostly arranged in 1–few(–several in I. gordonii var. wasatchensis) loose to capitate glomerules.
remaining straight.
6–9 mm diam.;
petals obovate, 2–3 × 1 mm;
filaments 0.8–1.2 mm;
styles 1–2 mm.
hypanthium shallowly cupulate or campanulate, sometimes turbinate (I. gordonii);
petals not medially reflexed, golden to pale yellow, sometimes white (I. utahensis) and then sometimes pink-tinged, not or scarcely clawed, apex acute to truncate, rounded, or emarginate;
stamens 5 (10 in I. pygmaea), anthers longer than wide, laterally dehiscent;
carpels (1–)2–15(–30 in I. pygmaea).
vertical, smooth or nearly so, not carunculate.
= 28.
Ivesia lycopodioides var. lycopodioides
Ivesia sect. Ivesia
Variety lycopodioides occurs in the Sierra Nevada from El Dorado and Alpine to Fresno counties, and on the Sweetwater Mountains of Mono County, California. The voucher reported by D. D. Keck (1938) from the Carson Range of Washoe County, Nevada, has not been located for confirmation. Of the three varieties, var. lycopodioides tends to have plants with the smallest leaflet lobes (ca. 1 mm) which lack apical setae. Plants also have more consistently simple caudices bearing a single rosette of glabrous or sparsely hairy leaves atop an enlarged, fleshy taproot.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Species 8 (8 in the flora).
Species in sect. Ivesia tend to form compact rosettes or tufts in open montane to alpine areas, often where rocky but generally not growing in rock crevices (except Ivesia longibracteata). General characteristics of the section are an overall evident glandularity, loosely to tightly cylindric leaves (mousetail-like in I. muirii), relatively short ascending to erect stems, straight pedicels, and flowers that are typically congested into 1–few capitate clusters that sometimes become more open in fruit. The taproots of some species, especially I. lycopodioides, are markedly enlarged, an adaptation to alpine growing conditions. The inclusion of two anomalous species in the section, I. longibracteata and I. webberi, is tentative; it is also possible that I. cryptocaulis belongs here rather than in sect. Setosae.
Section Ivesia has its center of species diversity in the high Sierra Nevada of California, where Ivesia pygmaea, with its ten stamens and more open habit, is possibly transitional between sects. Ivesia and Setosae. Ivesia gordonii (the most widespread species), I. tweedyi, and I. utahensis form an arc around the northern Great Basin, as outliers from the core Sierran distribution of the section.
Some early floras treated Ivesia pygmaea and I. lycopodioides as varieties of I. gordonii (for example, W. H. Brewer et al. 1876–1880, vol. 1) or Potentilla gordonii (Hooker) Greene (W. L. Jepson [1923–1925], 1909–1943, vol. 2). Recent treatments follow D. D. Keck (1938) in recognizing all three as distinct species; some annotations and references are nevertheless carried over from the earlier expanded circumscription of I. gordonii.
Since Ivesia cryptocaulis is sometimes identified as a member of sect. Ivesia, it is included herein and keys out in the seventh couplet.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
1. Epicalyx bractlets longer than sepals, 2.5–5 mm; leaves weakly planar to loosely ± cylindric; leaflets 5–6 per side; Castle Crags, n California. | I. longibracteata |
1. Epicalyx bractlets shorter than sepals, 0.5–3(–4 in I. gordonii) mm; leaves loosely to tightly cylindric; leaflets mostly 10–40 per side (4–10 in I. webberi); w United States | → 2 |
2. Plants silvery; leaves very tightly cylindric (mousetail-like, with leaflets scarcely distinguishable); leaflets 0.4–1 mm. | I. muirii |
2. Plants ± green; leaves loosely to tightly cylindric; leaflets distinguishable, (0.5–)2–13(–18) mm | → 3 |
3. Cauline leaves 2, paired; basal leaves: leaflets 4–8(–10) per side; petiole hairs 2–4 mm. | I. webberi |
3. Cauline leaves 0–2(–3), not paired; basal leaves: leaflets (6–)10–35 per side; petiole hairs 0.2–1.5 mm | → 4 |
4. Hypanthia turbinate to campanulate, (1.5–)2–4(–4.5) mm (± as deep as wide); petals narrowly oblanceolate to narrowly spatulate. | I. gordonii |
4. Hypanthia shallowly cupulate or shallowly campanulate, 1–2 mm (wider than deep); petals oblanceolate or broadly elliptic to spatulate or broadly obovate | → 5 |
5. Carpels (1–)2–6(–9); Idaho, Utah, Washington | → 6 |
5. Carpels (5–)8–30; e California, Nevada | → 7 |
6. Petals white, sometimes pink-tinged; stems prostrate to ascending; leaflets 2–4 mm; Utah. | I. utahensis |
6. Petals golden yellow; stems ascending to erect; leaflets 4–7(–10) mm; n Idaho, Washington. | I. tweedyi |
7. Plants diffusely matted; Spring Mountains, s Nevada. | I. cryptocaulis |
7. Plants rosetted to tufted or ± tightly matted; Sierra Nevada, White Mountains, and Sweetwater Mountains of e California and adjacent w Nevada | → 8 |
8. Stamens 10; sheathing bases usually ± strigose abaxially; taproots stout, not fleshy. | I. pygmaea |
8. Stamens 5; sheathing bases glabrous abaxially; taproots fusiform, fleshy. | I. lycopodioides |
CA
WildflowerSearch
iNaturalist
USDA Plants Database
