Micranthes rhomboidea

(Greene) Small in N. L. Britton et al.

in N. L. Britton et al., N. Amer. Fl. 22: 136. 1905 ,.

Common names: Diamond-leaf saxifrage
Basionym: Saxifraga rhomboidea Greene Pittonia 3: 343. 1898
Synonyms: Saxifraga austrina (A. Nelson) A. Nelson Saxifraga rhomboidea var. austrina A. Nelson Saxifraga rhomboidea var. franciscana (Small) Kearney & Peebles
Treatment appears in FNA Volume 8. Treatment on page 69. Mentioned on page 51, 65.

Plants solitary or tufted, with bulbils on caudices. Leaves basal; petiole flattened, 1–3 cm; blade broadly ovate to triangular, 1–3 cm, fleshy, base attenuate, margins coarsely serrate, ciliate, surfaces sparsely to moderately tangled, reddish brown-hairy abaxially, glabrous adaxially. Inflorescences (5–) 10–40-flowered, congested, ± glomerate or capitate thyrses, 4–20 cm, usually densely yellow to cream-tipped stipitate-glandular. Flowers: sepals ascending, ovate; petals white, not spotted, oblong to elliptic, clawed, 2–4 mm, 1.5+ times as long as sepals; filaments linear, flattened; pistils connate to 1/2 their lengths; ovary inferior, appearing more superior in fruit. Capsules purple, folliclelike. 2n = 20, 38, 40, 56.


Phenology: Flowering late spring–summer.
Habitat: Subalpine and alpine meadows
Elevation: 1500-4600 m

Distribution

V8 135-distribution-map.gif

Ariz., Colo., Idaho, Mont., N.Mex., Utah, Wyo.

Discussion

Micranthes rhomboidea is somewhat polymorphic; variants have been given taxonomic designations with little consistency. The chromosome number variation needs thorough study, as in other species of Micranthes, because no obvious correlations with morphology or geographic distribution are known (B. L. Bethers 1973). Reports from Canada (Alberta, Saskatchewan) were rejected as misidentifications of M. occidentalis.

Selected References

None.

Lower Taxa

None.

"full" is not a number.

... more about "Micranthes rhomboidea"
56 +, 40 +, 38 +  and 20 +
epigynous +, perigynous +  and hypogynous +
palmate +  and pinnate +
acute +  and obtuse or rounded +
Luc Brouillet +  and Patrick E. Elvander† +
(Greene) Small in N. L. Britton et al. +
attenuate +
Saxifraga rhomboidea +
dentate +, serrate +  and entire +
glandular-ciliate +  and ciliate +
broadly ovate +  and triangular +
1 cm10 mm <br />0.01 m <br /> (3 cm30 mm <br />0.03 m <br />) +
3-carpellate +  and 2-carpellate +
connate +  and distinct +
Diamond-leaf saxifrage +
ebracteate +, bracteate +  and 2-300(-1000+)-flowered +
Ariz. +, Colo. +, Idaho +, Mont. +, N.Mex. +, Utah +  and Wyo. +
1500-4600 m +
flattened +
bracteate +  and 2-70+[-1000]-flowered +
unisexual +  and bisexual +
2 cm20 mm <br />0.02 m <br /> (125 cm1,250 mm <br />1.25 m <br />) +
2-3(-4)-beaked +  and folliclelike +
Subalpine and alpine meadows +
multicellular +
glabrous +, stipitate-glandular +  and hairy +
purplish +  and green +
free +  and adnate +
0 cm0 mm <br />0 m <br /> (0.05 cm0.5 mm <br />5.0e-4 m <br />) +
cream-tipped +, capitate +, glomerate +, congested +  and (5-)10-40-flowered +
stipitate-glandular +
4 cm40 mm <br />0.04 m <br /> (20 cm200 mm <br />0.2 m <br />) +
opposite +  and alternate +
crassinucellate +, unitegmic +  and bitegmic +
epigynous +, perigynous +  and hypogynous +
purple-margined +
not spotted +  and white +
reddish purple +  and purple +
distinct +
1.5+ times as long as sepals +
clawed +, oblong +  and elliptic +
0.2 cm2 mm <br />0.002 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
peltate +  and jointed +
flattened +
1 cm10 mm <br />0.01 m <br /> (3 cm30 mm <br />0.03 m <br />) +
Flowering late spring–summer. +
2(-3)-carpellate +
0 +  and 1/2 +
unequal +
in N. L. Britton et al., N. Amer. Fl. +
straight +
muricate +, cellular-rugulose +, tuberculate +, pitted +, papillate +  and wrinkled +
ovoid +, ellipsoid +  and oblong +
reddish +  and green +
distinct +
unbranched +  and branched +
persistent +
horizontal +  and erect +
2 +  and 3 +
connate +  and distinct +
reddish brown-hairy +
Saxifraga austrina +, Saxifraga rhomboidea var. austrina +  and Saxifraga rhomboidea var. franciscana +
Micranthes rhomboidea +
Micranthes +
species +
dentate +, serrate +  and entire +
stoloniferous +  and rhizomatous +
tufted +  and solitary +
annual +, biennial +  and perennial +