The green links below add additional plants to the comparison table. Blue links lead to other Web sites.
enable glossary links

desert alyssum, desert madwort

Habit Annuals; canescent throughout except fruit, trichomes appressed, 8–20-rayed.
Stems

simple or few to several from base, erect, ascending, or decumbent, (0.2–)0.5–1.8(–2.8) dm.

Cauline leaves

subsessile or (proximal) attenuate to petiole-like base (to 0.5 cm);

blade linear to oblanceolate-linear, (0.3–)0.5–2.5(–3) cm × (0.5–)1–3(–4) mm (gradually smaller distally), base attenuate, apex acute.

Flowers

sepals oblong, 1.4–1.8(–2) × 0.4–0.5 mm, stellate-pubescent;

petals pale yellow, oblanceolate, 2–2.5 × 0.5–0.6 mm, base attenuate, apex obtuse or retuse, sparsely stellate-pubescent abaxially;

filaments: median pairs not toothed, gradually expanded from apex to narrowly winged base, lateral pair with broadly winged appendage apically notched into 2 teeth, 1–1.8(–2) mm;

anthers ovate, 0.1–0.2 mm.

Fruiting pedicels

ascending or subdivaricate, straight, stout, (1–)1.5–3.5(–4.5) mm, trichomes uniformly stellate.

Fruits

orbicular, 2.5–4(–4.5) mm diam., apex shallowly emarginate, usually glabrous;

valves uniformly inflated at middle, broadly flattened at margins, often glaucous, rarely sparsely pubescent (when young);

ovules 2 per ovary;

style 0.3–0.7 mm, glabrous.

Seeds

ovoid, slightly compressed, 1.2–1.5 × 0.9–1.1 mm, margined or not.

2n

= 32.

Alyssum desertorum

Phenology Flowering Apr–Jul.
Habitat Deserts, rocky areas, disturbed sites, roadsides, fields, meadows, sagebrush flats
Elevation 800-2000 m (2600-6600 ft)
Distribution
from FNA
CA; CO; ID; MT; ND; NE; NV; OR; SD; UT; WA; WY; AB; BC; SK; Europe; c Asia [Introduced in North America]
[WildflowerSearch map]
[BONAP county map]
Source FNA vol. 7, p. 248.
Parent taxa Brassicaceae > tribe Alysseae > Alyssum
Sibling taxa
A. alyssoides, A. murale, A. obovatum, A. simplex, A. szowitsianum
Name authority Stapf: Denkschr. Kaiserl. Akad. Wiss., Wien. Math.-Naturwiss. Kl. 51: 302. (1886)
Web links