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

perky sue, stemless four-nerve daisy, stemless hymenoxys, stemless woollybase

stone rubberweed, Torrey's four-nerve daisy

Habit Perennials, 2–30+ cm. Perennials, 2–15+ cm.
Caudices

± branched, branches notably thickened distally.

± branched, branches notably thickened distally.

Stems

1–35(–60), erect, unbranched.

1–30(–40), erect, unbranched.

Leaves

all basal, new leaves tightly clustered;

blades spatulate or oblanceolate to linear-oblanceolate, entire, glabrous or ± hairy, often lanuginose, sericeous, or strigoso-canescent, eglandular or ± gland-dotted.

all basal, new leaves tightly clustered;

blades (midribs usually pronounced) spatulate or oblanceolate to linear-oblanceolate, entire, glabrous or usually sparsely, sometimes moderately to densely, hairy, densely gland-dotted.

Peduncles

0.5–30 cm, ± hairy.

(0.5–)2–15 cm, ± hairy proximally, almost always densely lanate distally.

Involucres

7–12 × 8–16 mm.

10–12 × 12–15 mm.

Ray florets

8–15(–21);

corollas 9–19 mm.

7–14;

corollas 11–17 mm.

Disc florets

25–200+;

corollas yellow, 2.7–4.3 mm.

25–150+;

corollas yellow, 4–4.7 mm.

Outer phyllaries

6–12, 3.9–9(–11.5) mm, margins 0–0.4 mm wide, sometimes slightly scarious, abaxial faces ± hairy.

4–8, 6–8.5 mm, margins (0.3–)0.5–1.2 mm wide, usually conspicuously scarious, abaxial faces ± hairy.

Heads

1–35(–60) per plant, borne singly.

1–10(–40) per plant, borne singly.

Cypselae

2–4 mm;

pappi of 5–8 obovate to oblanceolate, aristate scales 2.2–3.7 mm.

3–4 mm;

pappi of 5–7 obovate to oblanceolate, aristate scales 3–4(–4.5) mm.

Tetraneuris acaulis

Tetraneuris torreyana

Phenology Flowering May–Jun(–Sep).
Habitat Roadsides, hillsides, slopes, open treeless areas, edges of woods
Elevation (1300–)1700–3100 m ((4300–)5600–10200 ft)
Distribution
from FNA
AZ; CA; CO; ID; KS; MT; ND; NE; NM; NV; OK; SD; TX; UT; WY; AB; SK
[WildflowerSearch map]
[BONAP county map]
from FNA
CO; MT; UT; WY
[WildflowerSearch map]
[BONAP county map]
Discussion

Varieties 4 (4 in the flora).

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

Key
1. Leaves sparsely to densely hairy, often lanuginose, sometimes sericeous, not strigoso-canescent; peduncles 0.5–8(–12) cm; outer phyllaries 6.8–9(–11.5) mm; growing at (2100–)3000–3900 m
var. caespitosa
1. Leaves sparsely to densely hairy, often strigoso-canescent; peduncles (1–)5–20(–30) cm; outer phyllaries 4–7.5 mm; growing at 700–2900(–3500) m
→ 2
2. Leaf blades usually densely, sometimes sparsely, strigoso-canescent; e of continental divide (except for 2 reports from nw Idaho)
var. acaulis
2. Leaf blades glabrous or sparsely to moderately to sometimes densely hairy, not strigoso-canescent; w of continental divide
→ 3
3. Leaf blades glabrous or usually sparsely to moderately or sometimes densely hairy, densely gland-dotted; n Arizona, se California, w Colorado, s Idaho, e Nevada, Utah
var. arizonica
3. Leaf blades glabrous or sparsely to moderately hairy, at least some (usually most or all) eglandular or sparsely gland-dotted; w Colorado, c, ne Utah, and sw Wyoming
var. epunctata
Source FNA vol. 21, p. 451. FNA vol. 21, p. 451.
Parent taxa Asteraceae > tribe Heliantheae > subtribe Gaillardiinae > Tetraneuris Asteraceae > tribe Heliantheae > subtribe Gaillardiinae > Tetraneuris
Sibling taxa
T. argentea, T. herbacea, T. ivesiana, T. linearifolia, T. scaposa, T. torreyana, T. turneri, T. verdiensis
T. acaulis, T. argentea, T. herbacea, T. ivesiana, T. linearifolia, T. scaposa, T. turneri, T. verdiensis
Subordinate taxa
T. acaulis var. acaulis, T. acaulis var. arizonica, T. acaulis var. caespitosa, T. acaulis var. epunctata
Synonyms Gaillardia acaulis, Hymenoxys acaulis Actinella torreyana, Hymenoxys depressa, Hymenoxys lapidicola, Hymenoxys torreyana, T. depressa
Name authority (Pursh) Greene: Pittonia 3: 265. (1898) (Nuttall) Greene: Pittonia 3: 265. (1898)
Web links