Grindelia squarrosa
Grindelia decumbens
curly-cup gumweed, curly-top gum-weed, resinweed, serrate resinweed
reclined gumweed
erect, usually whitish or stramineous, sometimes reddish or grayish, glabrous.
erect, stramineous, glabrous.
blades oval, ovate, obovate, or oblong to spatulate, oblanceolate, lanceolate, or linear, (10–)15–70 mm, lengths 2–5(–10) times widths, bases ± clasping, margins usually crenate to serrate (teeth mostly 3–6+ per cm, rounded to obtuse, resin-tipped), rarely entire, apices obtuse to acute, faces glabrous, strongly gland-dotted.
blades oblong, spatulate, oblanceolate, lanceolate, or linear, 15–40(–80) mm, lengths 3–7(–15) times widths, bases ± cuneate or clasping, margins serrate (teeth mostly distal, apiculate) or entire, apices obtuse to acute, faces glabrous, moderately gland-dotted.
broadly urceolate to hemispheric or globose, 6–11 × 8–20+ mm.
broadly urceolate to hemispheric, 5–9(–11) × 6–10(–15+) mm.
0 or (12–)24–36(–40);
laminae 8–14 mm.
12–24;
laminae 7–12 mm.
in 5–6 series, reflexed to spreading or appressed, filiform or linear to lance-linear or lance-subulate, apices usually looped to hooked, sometimes recurved to nearly straight, subterete to subulate, moderately to strongly resinous.
in 4–5(–6) series, slightly spreading to appressed, lance-oblong or lance-linear to lance-subulate, apices hooked or strongly recurved to nearly straight, subterete to subulate, slightly to moderately resinous.
usually in open to crowded, corymbiform arrays, rarely borne singly.
in open, paniculiform arrays.
whitish, stramineous, brown, or gray, 1.5–4.5 mm, apices smooth, coronate, or knobby, faces smooth, striate, or ± furrowed;
pappi of 2–3(–8), straight or contorted to curled, smooth or barbellulate to barbellate, subulate scales or setiform awns 2.5–5.5 mm, shorter than disc corollas.
light brown to stramineous, 3–3.5 mm, apices smooth or coronate, faces striate;
pappi of 2–4 straight or slightly contorted, smooth or barbellulate, setiform awns or subulate scales 3.5–5 mm, shorter than to equaling disc corollas.
= 12.
= 12.
Grindelia squarrosa
Grindelia decumbens
Grindelia squarrosa is probably native to the Great Plains and, perhaps, Rocky Mountain areas; it is widely introduced in other areas. Some plants are intermediate between it and G. hirsutula (i.e., between G. squarrosa and G. perennis, which has been treated as a variety of G. squarrosa). Plants of G. squarrosa with relatively narrow leaf blades (lengths mostly 5–8 times widths), mostly from the western part of the range of the species, have been treated as G. squarrosa var. serrulata. G. L. Nesom (1990i) and others have treated discoid plants included here in G. squarrosa as distinct (as G. aphanactis, G. nuda, and/or G. nuda vars. aphanactis and nuda); Nesom reported cypselae to be dimorphic in heads of radiate plants and monomorphic in discoid plants and noted that populations with discoid plants occur mostly south and west of populations with radiate plants. According to Nesom, plants of G. nuda with stems usually reddish (versus sometimes greenish), lengths of blades of mid-cauline leaves 4–10 (versus 1.5–4) times widths, and cypselae ± deeply furrowed (versus striate to shallowly furrowed) should be called G. nuda var. aphanactis.
Hybrids between Grindelia squarrosa (nuda) and G. arizonica have been recorded from Arizona and New Mexico.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Plants of Grindelia decumbens with leaf blades oblanceolate or lanceolate to linear with lengths 6–15 times widths (versus oblong or spatulate to oblanceolate with lengths 3–7 times widths) and phyllary apices gradually (versus abruptly) recurved have been called var. subincisa. Hybrids between G. decumbens and G. squarrosa (G. nuda) are known from Colorado. Plants treated here as G. decumbens are very similar to plants treated here within G. hirsutula.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
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