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Crater Lake sandwort, pumice sandwort

ball-head sandwort, capitate sandwort

Habit Plants tufted, green, not glaucous, slightly woody at base. Plants tufted or sometimes matted, green, not glaucous, with woody base.
Stems

erect, 10–20 cm, stipitate-glandular.

± erect, 3–40(–50) cm, glabrous or often stipitate-glandular.

Leaves

basal leaves ± deciduous;

cauline leaves (2–)3–5 of equal size distally;

basal blades ascending to ± spreading, narrowly linear, 1.5–3.5 cm × 1–1.5 mm, ± flexuous, ± succulent, apex green, blunt or acute to apiculate, glabrous, not glaucous.

basal leaves persistent or not;

cauline leaves in 3–5 pairs, similar, but reduced distally;

basal blades erect-ascending to arcuate-spreading, subulate or needlelike to filiform, (0.8–)2–11(–14) cm × 0.4–2 mm, flexuous or rigid, herbaceous to ± fleshy, apex obtuse to sharply acute or spinose, glabrous, sometimes glaucous.

Inflorescences

7–40+-flowered, ± open cymes.

3–50+-flowered, congested and capitate or sometimes open, umbellate cymes.

Pedicels

3–20 mm, stipitate-glandular.

0.1–7(–15) mm or ± absent, usually glabrous, rarely stipitate-glandular.

Flowers

sepals 1–3-veined, lateral pair obscure, ovate, 3–3.8 mm, 4–4.5 mm in fruit, margins broad, apex obtuse to rounded or barely acute, stipitate-glandular;

petals white, narrowly spatulate, 6.6–7.5 mm, 2 times as long as sepals, apex rounded or emarginate;

nectaries as lateral and abaxial rounding of base of filaments opposite sepals, 0.3 mm.

sepals 1–3-veined, sometimes obscurely so, ovate to lanceolate, 3–6.5 mm, not expanding in fruit, margins narrow, apex obtuse or acute to acuminate, rarely spinose, glabrous (or glandular in var. prolifera);

petals white, oblong, 5–8(–10) mm, 1.5–2 times as long as sepals, apex entire to slightly emarginate;

nectaries as lateral and abaxial mound with crescent-shaped groove at base of filaments opposite sepals, 0.3 × 0.15–0.2 mm.

Capsules

4.5–5.5 mm, glabrous.

3.5–6 mm, glabrous.

Seeds

black to brown, oblong to pyriform, 1.8–2.4 mm, smooth to tuberculate.

reddish brown to black, broadly ellipsoid to ovoid, 1.4–3 mm, tuberculate;

tubercles low, rounded, often elongate.

Eremogone pumicola

Eremogone congesta

Phenology Flowering summer.
Habitat Areas with loose pumice
Elevation 1600-2800 m (5200-9200 ft)
Distribution
from FNA
OR
[WildflowerSearch map]
[BONAP county map]
from FNA
CA; CO; ID; MT; NV; OR; UT; WA; WY; AB; SK
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[BONAP county map]
Discussion

Eremogone pumicola is restricted to Crater Lake and vicinity, southwestern Oregon.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Varieties 9 (9 in the flora).

Eremogone congesta is highly polymorphic; it has been been divided into 11 varieties (nine recognized here), most of which are distinctive and locally distributed. M. F. Baad (1969) noted two patterns of variation of different origin within E. congesta, but he did not present a revised classification.

While most specimens of the four varieties with dense inflorescences do not exhibit evident pedicels, the occasional plant does bear one or more pedicels to 1–2 mm, sometimes in secondary inflorescences.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Key
1. Pedicels usually 0.1-0.2 mm or ± absent; inflorescences dense, tight cymes
→ 2
1. Pedicels 1-6(-15) mm; inflorescences somewhat to markedly open cymes or umbellate cymes
→ 5
2. Basal leaf blades filiform, 3-14 cm
→ 3
2. Basal leaf blades needlelike, 1-3.5 cm
→ 4
3. Inflorescences capitate, rounded cymes; sepal apices obtuse to rounded
var. congesta
3. Inflorescences capitate, pyramidal cymes; sepal apices narrowly acute to acuminate
var. cephaloidea
4. Sepals 5-6.5 mm, apex acute to acuminate; basal leaf blades herbaceous; California, Nevada
var. simulans
4. Sepals 3.5-4 mm, apex obtuse; basal leaf blades ± succulent; California, Oregon
var. crassula
5. Sepal apices obtuse
→ 6
5. Sepal apices acute to acuminate or spinose
→ 7
6. Inflorescences proliferating, ± loose cymes; bracts often not closely enveloping sepals; Alberta, Saskatchewan, Colorado, Idaho, Montana, Utah, Wyoming
var. lithophila
6. Inflorescences umbels, bracts clustered at umbel base; California
var. suffrutescens
7. Basal leaf blades (2-)3-8 cm, filiform; pedicels glabrous or sometimes stipitate-glandular (possible throughout range, true for Nevada populations); Idaho, Nevada, Oregon, Washington
var. prolifera
7. Basal leaf blades 0.5-2.5(-3.5) cm, needlelike or filiform; pedicels glabrous; California, Nevada, Utah
→ 8
8. Inflorescences proliferating, ± loose cymes; sepals 3.5-4.5 mm
var. subcongesta
8. Inflorescences capitate and often rounded, to subcongested, proliferating or open cymes; sepals 4.5-6.5 mm
→ 9
9. Sepals 4.5-5.5 mm, weakly to conspicuously 1-3-veined, apex spinose
var. charlestonensis
9. Sepals usually 5.5-6.5 mm, conspicuously 3-veined, apex acute to acuminate
var. simulans
Source FNA vol. 5, p. 69. FNA vol. 5, p. 60.
Parent taxa Caryophyllaceae > subfam. Alsinoideae > Eremogone Caryophyllaceae > subfam. Alsinoideae > Eremogone
Sibling taxa
E. aberrans, E. aculeata, E. capillaris, E. congesta, E. eastwoodiae, E. fendleri, E. ferrisiae, E. franklinii, E. hookeri, E. kingii, E. macradenia, E. stenomeres, E. ursina
E. aberrans, E. aculeata, E. capillaris, E. eastwoodiae, E. fendleri, E. ferrisiae, E. franklinii, E. hookeri, E. kingii, E. macradenia, E. pumicola, E. stenomeres, E. ursina
Subordinate taxa
E. congesta var. cephaloidea, E. congesta var. charlestonensis, E. congesta var. congesta, E. congesta var. crassula, E. congesta var. lithophila, E. congesta var. prolifera, E. congesta var. simulans, E. congesta var. subcongesta, E. congesta var. suffrutescens
Synonyms Arenaria pumicola Arenaria congesta
Name authority (Coville & Leiberg) Ikonnikov: Novosti Syst. Vyssh. Rast. 10: 140. (1973) (Nuttall) Ikonnikov: Novosti Syst. Vyssh. Rast. 10: 139. (1973)
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