Lewisia

Pursh

Fl. Amer. Sept. 2: 360. 1814.

Etymology: For Meriwether Lewis, 1774–1809, American explorer
Synonyms: Erocallis Rydberg Oreobroma Howell
Treatment appears in FNA Volume 4. Treatment on page 476. Mentioned on page 458, 461.
 TaxonIllustrator 
FNA4 P77 Claytonia virginica.jpegClaytonia virginica
Lewisia cantelovii
Lewisia pygmaea
Lewisia rediviva var. rediviva
Barbara Alongi
Barbara Alongi
Barbara Alongi
Barbara Alongi
FNA4 P78 Lewisia triphylla.jpegLewisia triphylla
Montia chamissoi
Montia fontana
Barbara Alongi
Barbara Alongi
Barbara Alongi

Herbs, perennial, with enlarged caudices. Roots taproots, gradually ramified distally or fusiform to napiform, rarely globose and cormlike, fleshy. Stems deciduous, prostrate to erect, scapelike, simple or branched; nodes glabrous. Leaves basal or basal and cauline; basal leaves evergreen or ephemeral, in basal rosettes or tufts (except in L. triphylla); cauline leaves, if present, alternate, opposite, or whorled, ± sessile or gradually or abruptly narrowed basally into broad, clasping petiole; blade fleshy, margins entire, toothed, or crisped, often hyaline near base. Inflorescences racemose, paniculate, or subumbellate cymes, pedunculate, or with flowers borne singly; bracts persistent, 2 (–9) at each flowering node, subequal, margins entire, toothed, or glandular-toothed, herbaceous or scarious. Flowers pedicellate or sessile, persistent or disarticulate in fruit; sepals persistent, 2 (–9), equal or subequal when paired, margins entire, toothed, or glandular-toothed, herbaceous or scarious; petals (4–) 5–10 (–19), twisting about and falling away with capsules after anthesis; stamens 1–50, distinct to scarcely connate and/or adnate to petals basally; ovules 1–50; style branched; stigmas 2–8. Capsules dehiscence circumscissile near base, splitting from base toward apex. Seeds 1–50, brown or black, smooth or minutely sculpted, estrophiolate. x = 10, 11, 12, 13, 14, 15.

Distribution

w North America (including Mexico)

Discussion

Species 16 (16 in the flora).

The number and circumscription of species in Lewisia are not widely agreed upon because of morphological variability and intergradation. Natural hybridization is inferred for some plants. In cultivation, the species reputedly freely intercross; most hybrid offspring are sterile. Most species are cultivated by alpine/succulent plant enthusiasts. In the wild, the plants usually occur in small, isolated populations in rocky or gravelly places, especially in canyons or alpine flats.

The key to species here has been modified from B. Mathew (1989b). Hybrids, cultivars, and plants in cultivation may not key satisfactorily.

Key

1 Roots globose, cormlike; basal leaves usually senescent before anthesis; cauline leaves in single pair or whorl of 3(-5) Lewisia triphylla
1 Roots elongate, gradually ramified distally, or fusiform to napiform; basal leaves evergreen or senescent at or immediately following anthesis; cauline leaves in more than 1 opposite pair or alternate, or absent > 2
2 Basal leaves evergreen > 3
2 Basal leaves senescing at or soon after anthesis > 6
3 Basal leaf blades linear to narrowly oblanceolate, margins entire > 4
3 Basal leaf blades oblanceolate, spatulate, obovate, orbiculate, or very rarely nearly linear, margins entire or toothed > 5
4 Leaves ± terete Lewisia leeana
4 Leaves flattened or adaxial surface grooved Lewisia columbiana
5 Petals 5-9 mm, white to pale pink with darker veins; cymes loosely paniculate Lewisia cantelovii
5 Petals (8-)10-20 mm, usually pink-purple with pale and darker stripes, less often white, cream with pink-orange stripes, ± orange, or yellow; cymes densely paniculate to subumbellate Lewisia cotyledon
6 Flowers sessile; bract and sepal pairs decussate and appearing to form 4-merous calyx > 7
6 Flowers pedicellate; bracts and sepals not resembling 4-merous calyx > 8
7 Sepal margins toothed, sometimes glandular; petals 10-15 mm Lewisia kelloggii
7 Sepal margins entire, not glandular; petals 12-26 mm Lewisia brachycalyx
8 Flowers disarticulate in fruit; sepals 2-9, scarious at anthesis, margins entire to somewhat erose, not toothed > 9
8 Flowers not disarticulate in fruit; sepals 2, herbaceous at anthesis, margins entire, toothed, or glandular-toothed > 11
9 Sepals (4-)6-9; petals 10-19; proximalmost bracts in whorl of 4-7(-8) Lewisia rediviva
9 Sepals 2-4; petals 5-9; proximal bracts in 1 pair or whorl of 3-4 > 10
10 Sepals 2; petals 5-8; bracts ovate to lanceolate; flowers borne singly; s Sierra Nevada, California Lewisia disepala
10 Sepals 3-4; petals 7-9; bracts oblong to oblong-ovate; inflorescences 2-3-flowered or flowers borne singly; Nye County, Nevada Lewisia maguirei
11 Cauline leaves opposite, in 1-3 pairs, not markedly smaller than basal leaves Lewisia oppositifolia
11 Cauline leaves absent or alternate, markedly smaller than basal leaves > 12
12 Basal leaf blades oblanceolate, spatulate, or obovate; inflorescences paniculate or subumbellate cymes, 3-100-flowered > 13
12 Basal leaf blades linear to linear-oblanceolate; inflorescences 2-7-flowered racemose cymes or flowers borne singly > 14
13 Inflorescences 3-7-branched paniculate cymes, 20-100-flowered; petals 6-7, pale pink with yellow-green bases; stamens 4-5; Mari- posa County, California Lewisia congdonii
13 Inflorescences 1-3-branched subumbellate cymes, 3-11-flowered; petals 7-10, magenta or carmine with whitish bases; stamens 10-13; n Coast Ranges, California Lewisia stebbinsii
14 Flowers 2.5-4 cm diam.; Eldorado County, Nevada, and Placer County, California Lewisia longipetala
14 Flowers 0.5-2 cm diam.; more widely distributed > 15
15 Sepal margins mostly entire, sometimes obscurely or irregularly toothed, not glan- dular, apex acute to subacute; taproot napiform to shortly fusiform Lewisia nevadensis
15 Sepal margins regularly toothed, usually glandular-toothed (rarely ± entire), apex truncate or sometimes rounded, obtuse, subacute, or apiculate; taproot gradually ramified distally or shortly fusiform, rarely subnapiform Lewisia pygmaea

"broad" is not a number.

... more about "Lewisia"
Mark A. Hershkovitz +  and Sean B. Hogan +
ephemeral +  and evergreen +
occasionally dentate;crisped +
persistent +
subequal +
circumscissile +
enlarged +
gradually +  and sessile +
whorled +, opposite +  and alternate +
subumbellate +
w North America (including Mexico) +
For Meriwether Lewis, 1774–1809, American explorer +
sessile +  and pedicellate +
disarticulate in fruit +  and persistent +
paniculate +  and racemose +
terminal +  and axillary +
exstipulate +  and secund +
subrosulate +, rosulate +, alternate +, subopposite +  and opposite +
cauline +  and basal +
glandular-toothed +, toothed +, entire +  and crisped +
scarious +  and herbaceous +
plurilocular +
connate +  and distinct +
Fl. Amer. Sept. +
davidson2000a +, dempster1993a +, hohn1975a +  and mathew1989a +
estrophiolate +
black +  and brown +
1 +  and 50 +
sculptured +  and smooth +
sculpted +
persistent +
subequal +
distinct +  and scarcely connate and/or adnate +
1 +  and 50 +
branched +, simple +  and scapelike +
deciduous +
prostrate +  and erect +
2 +  and 8 +
Erocallis +  and Oreobroma +
Lewisia +
Portulacaceae +
fleshy +  and succulent +
15 +, 14 +, 13 +, 12 +, 11 +  and 10 +