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brittle sandwort, musk-flower, Nuttall sandwort, Nuttall's sandwort, Nuttall's stitchwort

annual sandwort, dwarf sandwort, dwarf stitchwort

Habit Plants perennial, mat-forming. Plants annual.
Taproots

thickened, woody;

crown, many-branched, woody;

rhizomes and trailing stems to 60 cm.

threadlike.

Stems

ascending to erect, ± green, 2–20 cm, densely glandular-hairy throughout, internodes of flowering stems 0.2–2 times as long as leaves.

spreading to erect, green, 1–5 cm, glabrous, internodes of all stems 2–10 times as long as leaves.

Leaves

tightly appressed to spreading, ± evenly spaced, connate proximally, with ± loose, scarious sheath 0.1–0.7 mm;

blade straight to recurved, ± green, flat, prominently 1-veined abaxially, broadly lanceolate to linear, 5–20 × 0.5–1.5 mm, ± rigid, margins rounded, scarious in proximal 1/3–1/4, apex green to purple, acute to acuminate or spinescent, navicular with small mucro or spinescent, dull, stipitate-glandular;

axillary leaves present proximally to throughout.

not overlapping, irregularly spaced, connate proximally, with loose, mostly herbaceous sheath 0.2–0.3 mm;

blade ascending to widely spreading, green, concave proximally, flat distally, obscurely 1-veined, awl-shaped to lanceolate, 1.5–5 × 0.2–1.5 mm, flexuous, margins not thickened, scarious throughout or proximally, smooth, apex green or purple, acute to obtuse, flat to navicular, often shiny, glabrous;

axillary leaves absent.

Inflorescences

(3–)6–30-flowered, open cymes;

bracts lanceolate to subulate, usually scarious.

2–9-flowered, open cymes;

bracts subulate, herbaceous, margins scarious proximally.

Pedicels

0.2–2 cm, stipitate-glandular.

0.1–0.5 cm, glabrous.

Flowers

hypanthium disc-shaped;

sepals 1–3-veined, narrowly lanceolate to lanceolate or ovate (herbaceous portion narrowly lanceolate to lanceolate or ovate), 3–6(–7) mm, not enlarging in fruit, apex often purple, acute to acuminate or spinescent, not hooded, stipitate-glandular;

petals obovate, 0.5–1.6 times as long as sepals, apex rounded, entire.

hypanthium disc-shaped;

sepals 1-veined, or weakly 3-veined in proximal 1/5, ovate to lanceolate (herbaceous portion lanceolate to narrowly so), 1.5–3.5 mm, not enlarging in fruit, apex green or purple, acute to acuminate, not hooded, glabrous;

petals narrowly lanceolate, 0.5–1 times as long as sepals, apex narrowly acute, entire, or absent.

Capsules

on stipe ca. 0.1–0.2 mm, ovoid, 5 mm, usually shorter than sepals.

on stipe ca. 0.1 mm, ± ovoid, ca. 3 mm, equaling or longer than sepals.

Seeds

reddish brown to dark brown, oblong-elliptic with hilar notch on 1 end, 1.5–2.7 mm, tuberculate;

tubercles low-rounded.

brown or reddish, asymmetically reniform with radicle prolonged into beak, not compressed, 0.5–0.6 mm, minutely papillate.

Minuartia nuttallii

Minuartia pusilla

Phenology Flowering spring–summer.
Habitat Plains, pine barrens, dry rock cliffs
Elevation 50-2400 m (200-7900 ft)
Distribution
from FNA
CA; CO; ID; MT; NV; OR; UT; WA; WY; AB; BC
[WildflowerSearch map]
[BONAP county map]
from FNA
CA; ID; NV; OR; UT; WA; BC
[WildflowerSearch map]
[BONAP county map]
Discussion

Varieties 4 (4 in the flora).

Minuartia nuttallii, M. decumbens, M. rosei, and M. stolonifera form a complex that, together with the eastern species M. caroliniana and M. michauxii, comprise sect. Sclerophylla Mattfeld. The four western species all have capsules that contain one to three(?) large (1.5–2.8 mm) seeds; unfortunately, these plants appear to be collected only rarely in fruit.

Minuartia nuttallii includes four varieties, which can, for the most part, be easily recognized. There is some overlap between var. gracilis and var. fragilis in western Nevada and southeastern Oregon, where some plants exhibit prominently arcuate-spreading leaves (as in var. fragilis) and weakly veined sepals (as in var. gracilis).

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

Key
1. Leaf blade apices spinecent; sepal apices spinescent
→ 2
1. Leaf blade apices acute to acuminate, somewhat navicular; sepal apices acuminate
→ 3
2. Leaves prominently arcuate-spreading, blade 10-20 mm; sepals (1-)3-veined
var. fragilis
2. Leaves appressed to occasionally arcuate- spreading, blade 5-7 mm; sepals 1(-3)-veined
var. gracilis
3. Sepals lanceolate to narrowly so; petals 0.5-1.2 times as long as sepals
var. nuttallii
3. Sepals ovate to lanceolate; petals 1.1-1.6 times as long as sepals
var. gregaria
Source FNA vol. 5, p. 129. FNA vol. 5, p. 132.
Parent taxa Caryophyllaceae > subfam. Alsinoideae > Minuartia Caryophyllaceae > subfam. Alsinoideae > Minuartia
Sibling taxa
M. arctica, M. austromontana, M. biflora, M. californica, M. caroliniana, M. cismontana, M. cumberlandensis, M. dawsonensis, M. decumbens, M. douglasii, M. drummondii, M. elegans, M. glabra, M. godfreyi, M. groenlandica, M. howellii, M. macrantha, M. macrocarpa, M. marcescens, M. michauxii, M. muscorum, M. obtusiloba, M. patula, M. pusilla, M. rosei, M. rossii, M. rubella, M. stolonifera, M. stricta, M. tenella, M. uniflora, M. yukonensis
M. arctica, M. austromontana, M. biflora, M. californica, M. caroliniana, M. cismontana, M. cumberlandensis, M. dawsonensis, M. decumbens, M. douglasii, M. drummondii, M. elegans, M. glabra, M. godfreyi, M. groenlandica, M. howellii, M. macrantha, M. macrocarpa, M. marcescens, M. michauxii, M. muscorum, M. nuttallii, M. obtusiloba, M. patula, M. rosei, M. rossii, M. rubella, M. stolonifera, M. stricta, M. tenella, M. uniflora, M. yukonensis
Subordinate taxa
M. nuttallii var. fragilis, M. nuttallii var. gracilis, M. nuttallii var. gregaria, M. nuttallii var. nuttallii
Synonyms Arenaria nuttallii, Minuopsis nuttallii Arenaria pusilla, Alsinopsis pusilla
Name authority (Pax) Briquet: Annuaire Conserv. Jard. Bot. Genève 13–14: 385. (1911) (S. Watson) Mattfeld: Bot. Jahrb. Syst. 57(Beibl. 126): 28. (1921)
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