Euthamia gymnospermoides
Euthamia
Great Plains goldentop, Texas goldentop, viscid grass-leaf goldenrod
goldentop, grass-leaf goldenrod
(simple or branched) glabrous or with scabrous lines, not glaucous.
erect (nearly terete), simple or branched, glabrous or hairy.
usually ascending;
blades (1–)3- or -5-nerved, linear to lanceolate, 40–100(–120) × 1.4–4(–8) mm, lengths 12–49 time widths, gradually reduced distally, firm-herbaceous, margins scabrous, apices acuminate, faces abundantly and prominently gland-dotted (29–49 dots per mm²), glabrous or midveins with hairs.
cauline; alternate;
sessile;
blades (± uniform along stems) linear to lanceolate (40–130 mm), margins entire, faces glabrous or hairy, sparsely to densely gland-dotted (dots obscure or evident, 0.1–0.25 mm diam., 0–86 per mm²).
obconic, (4–)4.5–6.2 mm.
obconic to hemispheric, (2.5–6.3 ×) 2.1–8.1 mm.
flat, pitted (pit borders ± fimbrillate), epaleate.
9–13(–16).
7–22(–35) (usually more numerous than disc florets), pistillate, fertile;
corollas yellow.
3–9;
corollas (3–)3.3–4.8 mm.
3–22, bisexual, fertile;
corollas yellow, tubes shorter than tubular to slender-funnelform throats, lobes 5, erect to ascending, oblong-lanceolate;
style-branch appendages lanceolate.
usually green-tipped, outer ovate, inner linear-oblong, apices obtuse to acute (± strongly resinous).
11–29 in 3–5 series, 1-nerved (flat), linear to ovate, bases often stramineous or pale, margins chartaceous or weakly cartilaginous, not scarious (apices with green zones, erose to ciliate), abaxial faces glabrous, little to very resinous.
(some or all) pedunculate (rarely all glomerate), usually in flat-topped to slightly rounded, arrays (25–)35–60% of plant heights.
radiate, borne singly or (glomerulate) in corymbiform or paniculiform arrays.
oblong to narrowly ellipsoid, ± terete, 2–4-nerved, strigose;
pappi persistent, of 20–30, white, ± equal, antrorsely barbellate, apically attenuate bristles in 1 series.
= 9.
= 36, 54.
Euthamia gymnospermoides
Euthamia
Some plants from the southern Great Lakes area with tendencies to shorter involucres and narrower leaves, called Euthamia gymnospermoides by H. A. Gleason and A. Cronquist (1991) and D. J. Sieren (1981), are better included in E. caroliniana.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Species 5 (5 in the flora).
Euthamia was formerly included in Solidago. Arrangements of heads, gland-dotted leaves, and DNA sequence data demonstrate that Euthamia should be treated as distinct from Solidago (L. C. Anderson and J. B. Creech 1975; R. D. Noyes and L. H. Rieseberg 1999).
Ambiguous and contradictory information has led to much debate about who named Euthamia (D. J. Sieren 1981; K. N. Gandhi 1999; G. L. Nesom 1999; J. L. Strother 2000). I consider correct authorship for this genus to be as given in Index Nominum Genericorum (http://ravenel.si.edu/botany/ing).
Euthamia is capable of tremendous phenotypic variation. Transitional aspects of a given plant are much more likely to be related to environmental factors than to introgression. Heights of arrays are determined by measuring from the summit of the plant to the bases of proximalmost head-bearing branches.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
1. Stems glabrous and glaucous; arrays of heads not flat-topped, lengths of proximal branches 0.18–0.56 times array heights (creating multistoried aspects to arrays); apices of inner phyllaries acute to acuminate | E. occidentalis |
1. Stems glabrous or hairy, not glaucous; arrays of heads usually flat-topped or rounded, lengths of proximal branches 0.5–1 times array heights; apices of inner phyllaries obtuse to acute | → 2 |
2. Disc corollas 2.5–3.3(–3.4) mm; involucres 3–4.7(–5.3) mm | → 3 |
2. Disc corollas 3.3–4.8 mm; involucres (4–)4.5–6.3 mm | → 4 |
3. Stems glabrous or glabrate; leaf blades usually 1–3 mm wide (to 6 mm wide in some Maine and Nova Scotia populations), faces glabrous or glabrate, abundantly and prominently gland-dotted | E. caroliniana |
3. Stems glabrous or densely spreading-hirtellous; leaf blades usually 3–12 mm wide, faces glabrous or densely spreading-hirtellous, usually sparsely and obscurely gland-dotted | E. graminifolia |
4. Leaf blades linear to lanceolate, lengths 12–49 times widths, gradually reduced distally, faces abundantly and prominently gland-dotted, not pustulate; arrays (25–)35–60% of plant heights | E. gymnospermoides |
4. Leaf blades lanceolate to narrowly lanceolate, lengths 8–18 times widths, abruptly reduced distally, faces little and obscurely gland-dotted, sometimes pustulate;arrays 6–35% of plant heights | E. leptocephala |
IL Wildflowers
KS Wildflowers
LA Plants
MN Wildflowers
MO Plants
WildflowerSearch
iNaturalist
USDA Plants Database
CA
OR
WA
Flora NW
PNW Herbaria
