Sibara
Sibara deserti
wing rockcress
desert rock cress, desert wing rockcress
erect, unbranched or branched distally.
often branched distally, 1–3.5(–4.5) dm, puberulent or glabrous.
basal and cauline;
petiolate;
basal rosulate or not, blade margins pectinate or pinnatisect;
cauline blade (base not auriculate), margins pectinate or pinnatisect, (terminal lobes filiform and semiterete, or linear and flat).
sometimes withered by flowering; rosulate or not.
petiole 5–1.7 cm;
blade (distal linear), margins pinnatisect: lobes linear to linear-lanceolate, 0.2–2 cm × 0.3–3 mm, margins entire, (surfaces glabrous or puberulent).
(several-flowered), considerably elongated in fruit.
(corymbose), rachis straight.
sepals erect, oblong [ovate], lateral pair not saccate basally (usually glabrous, rarely pubescent);
petals white, purple, or lavender, spatulate [oblanceolate] (longer than sepals), claw differentiated from blade, (often oblanceolate, equal to or longer than sepals, apex obtuse to emarginate);
stamens slightly tetradynamous;
filaments not dilated basally;
anthers ovate or oblong;
nectar glands lateral, semi-annular or annular, median glands absent.
sepals 1.5–2 × 0.5–0.7 mm, puberulent;
petals white, 2–3.5 × 0.5–1 mm, claw ca. 1.5 mm;
median filaments 1.2–1.5 mm;
anthers ovate, 0.3–0.4 mm.
divaricate-ascending, divaricate, horizontal, or reflexed, slender [stout].
divaricate or horizontal to reflexed, straight, recurved, or curved upward, (2–)3–5.5(–10) mm, glabrous or puberulent.
sessile or shortly stipitate, linear, smooth or torulose, latiseptate [terete];
valves each with prominent or obscure midvein, pubescent or glabrous;
replum rounded;
septum complete;
ovules [14–]16–40[–94] per ovary;
style distinct;
stigma capitate, entire.
divaricate-ascending to spreading or reflexed, often curved, smooth, (0.8–)1.2–2.5(–3.2) cm × 1.2–1.5 mm;
valves puberulent or glabrous;
ovules 16–24 per ovary;
style 1–2.5(–3) mm.
uniseriate or biseriate, (yellowish brown), flattened or plump, not winged, oblong;
seed coat not mucilaginous when wetted;
cotyledons accumbent [incumbent].
0.9–1.4 × 0.6–0.9 mm.
= 13, 14.
= 26, 28.
Sibara
Sibara deserti
Species 6 (2 in the flora).
As recognized by R. C. Rollins (1947, 1993), the limits of Sibara are highly artificial. One of the ten species that he recognized, S. virginica, is here placed in the monotypic genus Planodes of the tribe Cardamineae. Another, S. viereckii, is assigned to Dryopetalon, and S. grisea is reduced to synonymy under Thelypodium texanum. The four Mexican species recognized in the genus are S. angelorum (S. Watson) Greene (Baja California, Sonora), S. brandegeeana (Rose) Greene (Baja California), S. laxa (S. Watson) Greene (Baja California), and S. mexicana (S. Watson) Rollins (Guanajuato).
(Discussion copyrighted by Flora of North America; reprinted with permission.)
California collections examined are from Inyo County, and the only Nevada material I have studied is the type collection, from Amargosa Desert in southern Nye County.
R. C. Rollins (1947, 1993) separated Sibara deserti from S. rosulata primarily by having pendent to reflexed fruits less than 1–1.5 cm (versus divaricate-ascending fruits 1.5–3 cm), slender (versus club-shaped) styles, and presence (versus absence) of basal rosettes. These characters show continuous variation from one extreme to the other and are found in various combinations. The length and orientation of fruits can vary substantially in a single population or even on the same plant. For example, in Rollins & Munz 6743 and Rollins & Munz 6744 (both at GH and collected from the same general area) the fruits are ascending, divaricate, or reflexed and are 1.5–2.5 cm. Styles can be slender to stout, cylindrical to slightly club-shaped, and 1–3 mm; their considerable variation is independent of fruit length and orientation. Sibara deserti and S. rosulata are identical in leaf and trichome morphology, flower color and size, seed size, the overall range of variation in fruit size and length, and the orientation of fruiting pedicels. The complex represents a single species easily distinguished from the remaining North American members of Sibara by having minute, dendritic to forked (instead of simple) or no trichomes.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
1. Plants pubescent; petals 2-3.5 × 0.5-1 mm; fruits often curved, (0.8-)1.2-2.5(-3.2) cm × 1.2-1.5 mm; ovules 16-24 per ovary; deserts of e California, s Nevada. | S. deserti |
1. Plants glabrous; petals 3.5-6 × 2-3 mm; fruits straight, 2.5-4.1 cm × 0.7-0.9 mm; ovules 32-40 per ovary; Santa Cruz Island, California. | S. filifolia |
CA
WildflowerSearch
iNaturalist
USDA Plants Database
