Tetraneuris acaulis
Tetraneuris
perky sue, stemless four-nerve daisy, stemless hymenoxys, stemless woollybase
bitterweed, four-nerve daisy
± branched, branches notably thickened distally.
1–35(–60), erect, unbranched.
1–60, erect or ± decumbent, unbranched or sparingly branched distally.
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, or basal-proximal, or basal and cauline; alternate; petiolate or sessile;
blades (usually with distinct midribs) mostly oblanceolate to linear or filiform, sometimes lobed, ultimate margins usually entire, sometimes toothed, faces glabrous or ± hairy, eglandular or ± gland-dotted.
0.5–30 cm, ± hairy.
7–12 × 8–16 mm.
hemispheric to campanulate 6–20 mm diam.
hemispheric to conic, shallowly pitted or smooth, epaleate.
8–15(–21);
corollas 9–19 mm.
0 or 7–27, pistillate, fertile;
corollas (usually marcescent) yellow (laminae fan-shaped to oblanceolate, usually 3-lobed).
25–200+;
corollas yellow, 2.7–4.3 mm.
20–250+, bisexual, fertile;
corollas yellow proximally, yellow or purplish distally, tubes shorter than cylindric to cylindro-campanulate throats, lobes 5, ± deltate.
11–60+ in 3 series (mostly spreading to erect in fruit, distinct, herbaceous; outer with or without scarious margins, abaxial faces ± hairy; mid usually same number as, alternating with, and similar to outer, almost always with ± scarious margins; inner narrower than others, margins scarious).
6–12, 3.9–9(–11.5) mm, margins 0–0.4 mm wide, sometimes slightly scarious, abaxial faces ± hairy.
1–35(–60) per plant, borne singly.
radiate or discoid, borne singly or in paniculiform to corymbiform or fastigiate arrays.
2–4 mm;
pappi of 5–8 obovate to oblanceolate, aristate scales 2.2–3.7 mm.
± obpyramidal, moderately to densely hairy;
pappi persistent, of 4–8 usually aristate, scales.
= 15.
Tetraneuris acaulis
Tetraneuris
Varieties 4 (4 in the flora).
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Species 9 (9 in the flora).
Here, strigoso-canescent refers to often silvery induments (hairs tightly appressed, relatively short, 1–1.5 mm) of Tetraneuris argentea and T. acaulis var. acaulis. Such induments contrast with lanuginose or sericeous induments (hairs spreading, ca 1.5–3 mm) in other taxa, including T. ivesiana and the other three varieties of T. acaulis.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
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 |
1. Annuals | T. linearifolia |
1. Perennials (with caudices) | → 2 |
2. Caudices: branches not notably thickened distally; leaves all basal-proximal (not tightly clustered, internodes often evident) | → 3 |
2. Caudices: branches notably thickened distally; leaves all basal or basal and cauline (basal leaves tightly clustered, internodes usually not evident) | → 4 |
3. Stems erect; leaves sparsely to densely hairy, not woolly; Colorado, Kansas,Nebraska, New Mexico, Oklahoma, Texas | T. scaposa |
3. Stems erect or ± decumbent; leaves moderately to densely woolly; s Texas | T. turneri |
4. Leaves basal and cauline | → 5 |
4. Leaves all basal | → 6 |
5. Leaf blades ± densely strigoso-canescent | T. argentea |
5. Leaf blades glabrous or sparsely to moderately lanuginose to sericeous | T. ivesiana |
6. Ray florets 0 (leaves densely hairy, not strigoso-canescent; Yavapai County,Arizona) | T. verdiensis |
6. Ray florets usually 7–27 (if 0, leaves strigoso-canescent; widespread) | → 7 |
7. Rays 14–27; pappus scales usually non-aristate; Ontario, Illinois, Ohio | T. herbacea |
7. Rays 7–15(–21); pappus scales aristate; North Dakota to Texas and west | → 8 |
8. Leaves (midribs usually distinct) glabrous or usually sparsely, sometimes moderately or densely hairy (not strigoso-canescent or sericeous), gland-dotted; outer phyllaries 4–8, margins (0.3–)0.5–1.2 mm wide, usuallyconspicuously scarious | T. torreyana |
8. Leaves (midribs not very distinct) glabrous or ± hairy, often lanuginose, sericeous, or strigoso-canescent, eglandular or ± gland-dotted; outer phyllaries 6–12, margins 0–0.4 mm wide, sometimes slightly scarious | T. acaulis |
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