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

Walker's evening-primrose, Walker's sun-cup

golden suncup, Mojave suncup, yellow cups

Habit Herbs annual or short-lived perennial, villous, usually densely so proximally, less dense to glabrate distally, sometimes hairs somewhat appressed and shorter on leaves, also sometimes glandular puberulent on distal parts. Herbs annual, moderately to densely villous, sometimes strigillose.
Stems

slender, unbranched or branched from base, 10–60 cm.

branched, 3–75 cm.

Leaves

in basal rosette and/or cauline, often purple-dotted, 2–22 × 0.4–3.5 cm;

petiole 0.4–8 cm;

blade pinnately lobed, sometimes lateral lobes greatly reduced or absent and blade reduced to terminal lobe only, terminal lobe oblong or cordate to ovate, 1–5 × 0.5–3.2 cm, margins serrate, brown oil cells prominently lining veins abaxially.

primarily in basal rosette, cauline greatly reduced when present, 6–14 × 1.5–3.5 cm;

petiole 1.5–4(–11) cm;

blade pinnately lobed or lateral lobes greatly reduced or absent, often mixed on same plant, terminal lobe usually ovate, rarely elliptic, 2.5–6.9 × 1.5–7 cm, margins irregularly dentate, oil cells on abaxial surface inconspicuous.

Racemes

erect, elongating after anthesis.

nodding, mostly elongating after flowers.

Flowers

opening at sunrise;

buds individually reflexed, with apical free tips less than 1 mm;

floral tube 0.5–1.5 mm, glabrous or sparsely villous inside;

sepals 1.5–5 mm;

petals bright yellow, fading pale orange or lavender, 1–6 mm;

stamens unequal, filaments of antisepalous stamens 1–3 mm, those of antipetalous ones 0.3–2 mm, anthers 0.5–2 mm, glabrous or sparsely ciliate;

style 1.5–6 mm, stigma surrounded by anthers at anthesis.

opening at sunrise;

buds sometimes individually reflexed, without free tips or with subapical free tips 1–2 mm, or with minute, apical free tips less than 1 mm;

floral tube 3–8 mm, densely short-villous inside proximally;

sepals 5–9 mm;

petals bright yellow, sometimes with red dots at base, fading yellow to orange or reddish, 3–18 mm;

stamens subequal, filaments 3–6 mm, anthers 2.5–6 mm, ciliate;

style 10–18 mm, stigma exserted beyond anthers at anthesis.

Capsules

spreading or ascending, oblong-cylindrical, 11–45 mm;

pedicel 5–30 mm.

ascending or spreading, oblong-cylindrical, 18–92 mm;

pedicel 2–20 mm.

Seeds

0.6–1.2 mm.

1–1.5 mm.

Chylismia walkeri

Chylismia brevipes

Distribution
sw United States
[WildflowerSearch map]
[BONAP county map]
sw United States
[WildflowerSearch map]
[BONAP county map]
Discussion

Subspecies 2 (2 in the flora).

P. H. Raven (1962, 1969) determined this species to be self-incompatible and primarily autogamous.

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

Subspecies 3 (3 in the flora).

P. H. Raven (1962, 1969) determined this species to be self-incompatible.

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

Key
1. Leaves primarily cauline, rarely forming inconspicuous basal rosette, lateral lobes usually greatly reduced or absent; petals 1–3 mm; anthers 0.5–0.8 mm.
subsp. walkeri
1. Leaves primarily basal, forming conspicuous rosette, cauline reduced or absent, lateral lobes usually well developed; petals 2.8–6 mm; anthers 1–2 mm.
subsp. tortilis
1. Flower buds individually reflexed; petals often fading reddish, 3–8 mm.
subsp. arizonica
1. Flower buds not individually reflexed; petals fading yellow to orange, 6–18 mm.
→ 2
2. Plants stout, villous; buds with subapical free tips 1–2 mm; petals usually without red dots at base.
subsp. brevipes
2. Plants slender, usually strigillose, sometimes also villous proximally; buds with apical free tips 0–1 mm; petals often with red dots near base.
subsp. pallidula
Source FNA vol. 10. FNA vol. 10.
Parent taxa Onagraceae > subfam. Onagroideae > tribe Onagreae > Chylismia > sect. Chylismia Onagraceae > subfam. Onagroideae > tribe Onagreae > Chylismia > sect. Chylismia
Sibling taxa
C. arenaria, C. atwoodii, C. brevipes, C. cardiophylla, C. claviformis, C. confertiflora, C. eastwoodiae, C. exilis, C. heterochroma, C. megalantha, C. multijuga, C. munzii, C. parryi, C. scapoidea, C. specicola
C. arenaria, C. atwoodii, C. cardiophylla, C. claviformis, C. confertiflora, C. eastwoodiae, C. exilis, C. heterochroma, C. megalantha, C. multijuga, C. munzii, C. parryi, C. scapoidea, C. specicola, C. walkeri
Subordinate taxa
C. walkeri subsp. tortilis, C. walkeri subsp. walkeri
C. brevipes subsp. arizonica, C. brevipes subsp. brevipes, C. brevipes subsp. pallidula
Synonyms Camissonia walkeri, Oenothera walkeri Oenothera brevipes, Camissonia brevipes
Name authority A. Nelson: Bot. Gaz. 56: 66. (1913) — (as Chylisma) (A. Gray) Small: Bull. Torrey Bot. Club 23: 194. (1896) — (as Chylisma)
Web links