FNA: Erysimum vs. Erysimum menziesii

Phenology

Flowering Jan–Aug.

Habitat

Stabilized coastal sand dunes

Elevation

0-300 m (0-1000 ft)

Distribution

North America; n Mexico; Central America; Europe; Asia; n Africa; Atlantic Islands (Macaronesia) [Introduced in South America, Australia]

[BONAP county map]

CA

[WildflowerSearch map]

[BONAP county map]

Discussion

Species ca. 150 (19 in the flora).

Erysimum is found in the northern hemisphere, primarily Asia and Europe, with eight species in northern Africa and Macaronesia, and one each endemic to Baja California (E. moranii Rollins) and Costa Rica and Guatemala (E. ghiesbreghtii J. D. Smith). Of the 21 species found in North America, four are naturalized. Most of the native species have x = 9 and are believed to represent a monophyletic group (R. A. Price 1987).

Erysimum is a taxonomically difficult genus much in need of comprehensive phylogenetic and systematic studies covering its entire range. The principal sources of difficulty are the inflation in the number of species described, the heavy reliance on vegetative morphological characters in the delimitation of species, and the inadequacy of most herbarium specimens. In order to reliably identify a given sample, one often needs a complete specimen that has basal leaves, flowers, mature fruits, and seeds. Unfortunately, plants of most species shed their basal leaves or have no flowers when at full fruit maturity. Another complicating factor in North America is that almost all of the native species readily hybridize in areas of overlap to produce wide arrays of intermediates that backcross with the parents and blur species boundaries.

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

Of conservation concern.

Erysimum menziesii is restricted to the coasts of Humboldt, Mendocino, and Monterey counties. R. A. Price (1993) divided the species into four subspecies, three of which were invalidly published.

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

Key

1. Petals 3-10(-15) × 1.5-3 mm; median filaments 2-7(-10) mm	→ 2
1. Petals (10-)13-30(-35) × 3-10(-15) mm; median filaments (6-)7-15 mm	→ 6
2. Fruit valves densely pubescent inside; sepals 1.8-3.2 mm; petal claws 1.5-3.5 mm.	E. cheiranthoides
2. Fruit valves usually glabrous inside, rarely sparsely pubescent; sepals 4-7(-8) mm; petal claws 3-8 mm	→ 3
3. Annuals; fruiting pedicels as wide as fruit.	E. repandum
3. Biennials or perennials (short-lived); fruiting pedicels narrower than fruit	→ 4
4. Stigmas entire; fruits appressed to rachises; leaf blade surfaces and fruit valves with 3- and 4-rayed trichomes.	E. hieraciifolium
4. Stigmas strongly 2-lobed; fruits not appressed or subappressed to rachises; leaf blade surfaces and fruit valves with 2- or 3-rayed trichomes	→ 5
5. Petals narrowly obovate to spatulate, (8-)10-15 × (2-)2.5-4 mm; fruits 1.8-2.5 mm wide; seeds 1.5-2 mm.	E. coarctatum
5. Petals oblanceolate, 6-9(-11) × 1-2 mm; fruits 1.2-1.7 mm wide; seeds 1.2-1.7 × 0.8-1 mm.	E. inconspicuum
6. Subshrubs (stems woody at base)	→ 7
6. Biennials or perennials (stems not woody at base)	→ 10
7. Fruit valve trichomes 2-rayed; stigmas strongly 2-lobed, lobes much longer than wide; petals orange, yellow, brown, red, purple, violet, or white.	E. cheiri
7. Fruit valve trichomes 2-4-rayed; stigmas not strongly 2-lobed, lobes as long as wide; petals yellow or cream	→ 8
8. Fruits angustiseptate; leaf trichomes 2- or 3-rayed.	E. insulare
8. Fruits latispetate or 4-angled; leaf trichomes 2-5-rayed	→ 9
9. Distal cauline leaves petiolate; fruits latiseptate, not 4-angled; fruiting pedicels stout, 5-17(-22) mm.	E. franciscanum
9. Distal cauline leaves sessile; fruits slightly latiseptate or 4-angled; fruiting pedicels slender, (3-)5-10 mm.	E. suffrutescens
10. Petals purple or lilac; leaf trichomes 2-rayed; sepals 5-9 mm; anthers 1-1.5 mm.	E. pallasii
10. Petals usually yellow or orange, rarely lavender or purplish; leaf trichomes (at least some) 3-7-rayed; sepals 7-14 mm; anthers 2-4 mm	→ 11
11. Basal leaf blades filiform to narrowly linear, (somewhat revolute, appearing terete).	E. teretifolium
11. Basal leaf blades not filiform or narrowly linear	→ 12
12. Fruits 4-angled, longitudinally 4-striped; valves densely pubescent between midvein and replum with 2-rayed trichomes; ovules 72-120 per ovary.	E. asperum
12. Fruits latiseptate, rarely 4-angled, not longitudinally striped; valves pubescent with 2-6-rayed trichomes; ovules 24-86 per ovary	→ 13
13. Leaf blades: surfaces with 2 (or 3)-rayed trichomes	→ 14
13. Leaf blades: surfaces with 2-5(-7)-rayed trichomes	→ 16
14. Fruits usually 4-angled, rarely latiseptate; ovules (40-)54-82 per ovary; seeds not winged, 1.5-2(-2.4) mm.	E. capitatum
14. Fruits strongly latiseptate; ovules 24-46 per ovary; seeds usually broadly winged all around or apically, rarely not winged, 2-3.5 mm	→ 15
15. Perennials; seeds not winged or winged distally; fruits 1.5-2.7 mm wide.	E. arenicola
15. Biennials; seeds winged all around; fruits (2-)2.4-3.7 mm wide.	E. occidentale
16. Fruits torulose; ovules 26-44 per ovary; petals 3.5-6 mm wide.	E. perenne
16. Fruits not torulose; ovules (32-)42-86 per ovary; petals (5-)6-16 mm wide	→ 17
17. Fruiting pedicels 2-4(-6) mm; seeds broadly obovate to suborbicular, 1.5-3 mm wide.	E. concinnum
17. Fruiting pedicels 4-17(-25) mm; seeds oblong, 1-2 mm wide	→ 18
18. Fruits divaricate, ascending, or erect; petals orange or orange-yellow to yellow; seeds winged distally; Midwestern, Mountain, Pacific states.	E. capitatum
18. Fruits spreading; petals yellow; seeds winged all around; California (Humboldt, Mendocino, Monterrey, Santa Cruz counties)	→ 19
19. Basal leaf blades linear-oblanceolate, 2-9 mm wide; stems 0.4-9(-13) dm; fruit valves each with prominent midvein; ovules 50-86 per ovary.	E. ammophilum
19. Basal leaf blades spatulate, 5-15 mm wide; stems 0.2-2.5(-3.5) dm; fruit valves each with obscure midvein; ovules 32-74 per ovary.	E. menziesii