Grindelia squarrosa
Grindelia howellii
curly-cup gumweed, curly-top gum-weed, resinweed, serrate resinweed
Howell's gumweed
erect, usually whitish or stramineous, sometimes reddish or grayish, glabrous.
erect, stramineous to red-brown, stipitate-glandular (at least distally).
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 spatulate or oblong to oblanceolate or lanceolate, 25–60(–90) mm, lengths 3–5(–7) times widths, bases cuneate to ± clasping, margins entire or serrate to denticulate (teeth apiculate), apices obtuse to acute, faces usually finely stipitate-glandular, sometimes glabrous (or scabridulous near margins) and gland-dotted.
broadly urceolate to hemispheric or globose, 6–11 × 8–20+ mm.
broadly urceolate to globose, 8–15 × 12–20(–30) mm.
0 or (12–)24–36(–40);
laminae 8–14 mm.
20–30+;
laminae 8–12 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 6–9 series, spreading to appressed, linear or linear-attenuate to lance-linear, apices mostly looped to hooked (inner sometimes recurved to straight), ± terete, moderately to strongly resinous.
usually in open to crowded, corymbiform arrays, rarely borne singly.
in open to crowded, corymbiform to 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.
whitish to stramineous, 4–5.5 mm, apices ± coronate, faces striate or furrowed;
pappi of 2 straight to curled, usually smooth, sometimes barbellulate, subulate scales 2.5–4+ mm, shorter than disc corollas.
= 12.
Grindelia squarrosa
Grindelia howellii
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.)
Of conservation concern.
But for the usually stipitate-glandular indument of the stems and leaves, plants called Grindelia howellii are very much like plants that have been called G. nana forma brownii Steyermark, G. nana forma longisquama Steyermark, and G. paysonorum H. St. John [= G. nana var. paysonorum (H. St. John) Steyermark], all typified by specimens included here in G. hirsutula. In some plants of G. howellii, the glands on the leaves range from stipitate to ± embedded (e.g., Pierce 1146, ID). Taxonomic rank for plants that have been called G. howellii should be reconsidered.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
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