Flora of North America species comparison

Occurrence of Grindelia hirsutula in Alaska was not verified for this treatment. As circumscribed here, Grindelia hirsutula includes 30 or more reputedly distinct, local, regional, or ecotypic facies that have been named at species or infraspecific rank. Locally, such facies are easily recognized; in a broad view, they intergrade with other facies and are parts of a heterogeneous continuum. Taxonomies that have attempted to recognize the facies as distinct “taxa” have led to almost as many specimens determined as “intermediate” as are assigned to the named “taxa.”

Following, alphabetically by epithet, we have summarized names, diagnostic traits (mostly as given in regional and/or state floras), and distributions for “taxa” treated as distinct in some taxonomies and included within Grindelia hirsutula here:

acutifolia: Grindelia acutifolia; cauline leaf blades firmly membranous, lengths 2.5–5 times widths, phyllary apices looped to hooked, pappi of 2–3, subulate scales; southeastern Colorado, northeastern New Mexico Hybrids between G. acutifolia and G. squarrosa (as G. nuda) have been recorded from the Colorado side of Raton Pass.

altissima: Grindelia nana var. altissima; distal cauline leaves smaller and more scattered than proximal, blades about as wide at bases as at mid points, heads relatively few, heights of involucres less than diams.; mostly inner coastal ranges, northern California, southern Oregon. M. A. Lane (1993b) considered altissima to apply to hybrids between davyi and nana.

angusta: Grindelia inornata var. angusta; cauline leaf blades oblong to oblong-lanceolate, lengths 3+ times widths, faces inconspicuously gland-dotted, ray florets 0, cypselae stramineous to pale brown; central Colorado.

angustifolia: Grindelia stricta var. angustifolia; see humilis.

blakei: Grindelia stricta subsp. blakei; see humilis.

bracteosa: Grindelia bracteosa; G. camporum var. bracteosa; G. robusta var. bracteosa; stems usually whitish and resinous, lengths of cauline leaf blades 3–5 times widths, phyllary apices usually looped, ray florets 0 or 2–27; southern California. M. A. Lane (1993b) suggested that bracteosa may have derived from hybridization between hirsutula and G. squarrosa (var. serrulata). See also, robusta.

camporum: Grindelia camporum; stems usually whitish and resinous, cauline leaf blades ovate to lanceolate, involucres seldom subtended by bracts, phyllary apices recurved to straight, ray florets 32–39; mostly interior north, central California.

columbiana: Grindelia nana [unranked] columbiana; G. columbiana; ray florets 0, otherwise much like nana; Idaho, Oregon, Washington (mostly Columbia River drainage).

davyi: Grindelia camporum var. davyi; G. hirsutula var. davyi; G. robusta var. davyi; phyllary apices recurved to straight, acuminate, pappi usually ± equaling disc corollas; interior northern California. M. A. Lane (1993b) suggested that davyi may have derived from hybridization between camporum and hirsutula.

fastigiata: Grindelia fastigiata; cauline leaf blades conspicuously gland-dotted, phyllary apices thick, coriaceous, ray florets 0, cypselae brown; western Colorado and eastern Utah. Hybrids between fastigiata and G. squarrosa have been recorded from Utah.

hallii: Grindelia hallii; G. hirsutula var. hallii; involucres 8–12 mm diam., phyllary apices slightly recurved and attenuate to nearly straight and deltate, pappi shorter than disc corollas; interior southern California.

hirsutula: Grindelia hirsutula; stems usually green to reddish, ± hirsutulous to arachnose (at least distally), cauline leaf blades usually widest proximal to their midpoints, involucres 12–23 mm diam., often subtended by leaflike bracts, phyllary apices mostly recurved to straight, slightly to moderately resinous, ray florets usually 20–60, laminae 14–20 mm, cypselae usually reddish; mostly coastal ranges of California.

humilis: Grindelia humilis Hooker & Arnott; about the nomenclatural type of G. humilis, M. A. Lane (1992b) stated “...clearly conspecific with G. hirsutula” and she used the name G. stricta var. angustifolia for plants others had treated as G. humilis; as used by others, humilis has been applied to subshrubs 100–150 cm with red-brown stems and phyllary apices recurved to nearly straight from tidal lands around San Francisco and Tomales bays in northern California; similar plants but for apices of phyllaries often looped to hooked from around Humboldt Bay in northern California have been called blakei.

inornata: Grindelia inornata; cauline leaf blades oblanceolate or ovate to oblong, lengths 1.5–3 times widths, faces inconspicuously gland-dotted, ray florets 0, cypselae stramineous to pale brown; central Colorado. Hybrids between inornata and G. subalpina have been recorded from Colorado.

integerrima: Grindelia nana var. integerrima; see integrifolia.

integrifolia: Grindelia nana var. integrifolia Nuttall (not G. integrifolia de Candolle); G. squarrosa var. integrifolia; cauline leaf blades oblanceolate, margins subentire, phyllary apices (at least the outer) looped to hooked, pappi of curled, smooth to barbellulate, subulate scales scarcely longer than cypselae; Idaho, Montana, Nevada, Oregon, Utah, Washington.

latifolia: Grindelia latifolia; stems herbaceous, decumbent to prostrate, leaf blade apices rounded, obtuse, or acute; coastal central and southern California (including Channel Islands).

macrophylla: Grindelia macrophylla; G. integrifolia var. macrophylla; G. stricta var. macrophylla; see stricta.

maritima: G. hirsutula var. maritima; G. maritima (Greene) Steyermark; G. rubricaulis var. maritima; stems ascending, 30–80 cm, openly branched, involucres 12–25 mm diam., phyllary apices slightly recurved to nearly straight, cypselae golden or grayish, lengths of pappi ± 1/2 disc corollas; coastal central California. M. A. Lane (1993b) suggested that maritima may have derived from hybridization between hirsutula and platyphylla.

nana: Grindelia nana; stems yellowish to reddish, not resinous, cauline leaf blades usually oblanceolate, lengths usually 5–8 times widths, margins entire or (distally) serrate, involucres mostly 7–10 × 9–15 mm, phyllary apices looped or nearly straight; interior British Columbia, northern California, Idaho, western Montana, northern Nevada, Oregon, Washington.

paludosa: Grindelia paludosa; the nomenclatural type may be a hybrid; stems herbaceous, 50–150 cm, cauline leaf blades coriaceous, little, or not at all, gland-dotted, outer phyllary apices looped, strongly resinous; around Suisun Bay, northern California.

parviflora: Grindelia camporum var. parviflora; see procera.

perennis: Grindelia perennis; perennials, cauline leaf blades oblong to oblanceolate, lengths 6–8 times widths, margins entire or remotely serrulate, phyllary apices strongly resinous, pappi of 2–4 subulate scales; Alberta, British Columbia, Manitoba, Northwest Territories, Ontario, Saskatchewan; Arizona, Colorado, Idaho, Illinois, Michigan, Minnesota, Missouri, Montana, Nebraska, Nevada, New Mexico, New York, North Dakota, Pennsylvania, South Dakota, Utah, Washington, Wyoming.

platyphylla: Grindelia latifolia subsp. platyphylla; G. robusta var. platyphylla; G. stricta var. platyphylla; stems herbaceous (caudices woody), greenish, decumbent to prostrate, cauline leaf blades widest proximal to mid points, apices rounded to truncate; dunes and coastal bluffs, central and southern California.

procera: Grindelia procera; stems erect, 80–180 cm, strictly branching distally, phyllary apices nearly patent to straight, glabrous, slightly resinous, ray florets 21–45, laminae 8–10 mm; mostly interior central California.

quasiperennis: Grindelia squarrosa var. quasiperennis; see perennis.

revoluta: Grindelia revoluta; perennials (possibly flowering first year), stems glabrous, cauline leaf blades subcoriaceous, thickened, lengths 2.5–5 times widths, margins entire or remotely dentate to denticulate with short, broad teeth, phyllary apices usually looped, strongly resinous, ray florets 21–37, pappi of 2–4 subulate scales; central and south central Colorado.

rigida: Grindelia robusta var. rigida; see camporum.

robusta: Grindelia robusta; fide M. A. Lane (1992b), the nomenclatural type of G. robusta is a hybrid that came from a cross between plants assignable to G. hirsutula in the sense of Lane and plants assignable to G. stricta in the sense of Lane. Within Lane’s interpretation and taxonomic constraints, G. robusta cannot be placed in synonymy of the species name of either “parent.” We believe instead that the type of robusta belongs to the “taxon” that has been called bracteosa.

rubricaulis: Grindelia rubricaulis; G. hirsutula subsp. rubricaulis; the type of rubricaulis is very much like the type of hirsutula [see above].

stricta: Grindelia stricta; stems usually green to reddish, prostrate to erect, usually ± hirsutulous to arachnose (at least distally), sometimes glabrous, cauline leaf blades usually widest distal to their midpoints, involucres mostly 10–50 mm diam., sometimes subtended by bracteoles, phyllary apices usually slightly recurved to straight, slightly to moderately resinous, ray florets 30–60, laminae 13–25 mm, scales of pappi 0.3+ mm wide at bases; mostly coastal beaches and marshes; British Columbia, Alaska, California, Oregon, Washington.

venulosa: Grindelia stricta subsp. venulosa; stems procumbent to decumbent, whitish to yellowish, cauline leaf blades fleshy, apices rounded, phyllary apices looped; coastal bluffs and marshes; California, Oregon.

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

Species ca. 30 (18 in the flora).

The last attempt to account for the whole of Grindelia was by J. A. Steyermark (1934b). After comparing Steyermark’s treatment with specimens, one gets the impression that Steyermark had a keen eye for subtleties and trends in variation and that he sometimes assigned taxonomic ranks (species, variety, and forma) to trends rather than to what most botanists would consider to be taxa. Subsequently, writers of local and regional floras have felt obliged to recognize Steyermark’s “taxa.” Here, some of Steyermark’s “taxa” have been included within more broadly drawn circumscriptions; attention is called to them in discussions.

Within and among populations of grindelias, some morphologic traits appear to vary more from plant to plant than in most genera of composites. M. P. Dunford (1964) reported grindelias he had tested to be “essentially self-incompatible” and (1986) stated, “...Grindelia species are outcrossing and self-incompatible....” Some patterns of variation within Grindelia are similar to those found in genera characterized by apomictic seed production (e.g., local morphologic variants such as discoid plants in otherwise radiate taxa, hairy plants in otherwise glabrous taxa, narrow-leaved plants in otherwise broad-leaved taxa, etc.). See comments in discussion under 13. G. hirsutula.

References here to hybrids are based on observations by M. A. Wetter and/or on statements by M. P. Dunford (1964, 1986) and J. A. Steyermark (1934b).

Morphologic details and descriptive conventions for grindelias as treated here are:

Margins of most cauline leaves of most grindelias are usually dentate to serrate and have sharp, apiculate to setose teeth. Some species characteristically have cauline leaves with ± crenate margins and rounded, obtuse, or truncate teeth tipped by resin globules. Sporadically, individual plants may have some teeth resin-tipped and some teeth apiculate; such specimens may be hybrids or may indicate that the developmental paths to the two forms may be easily redirected. Plants with margins of some or all leaves entire may be encountered in almost all species of Grindelia and may predominate in some plants, populations, or species.

Leaf faces are usually gland-dotted with glands embedded in (or sessile in pits in) both the abaxial and adaxial epidermes. In some plants, populations, or species, the glands may be characteristically stipitate; developmental control for the different forms is apparently easily redirected (see comments under 11. Grindelia howellii).

Phyllaries are usually ± chartaceous proximally and herbaceous distally. Orientations of whole phyllaries and of their herbaceous apices are addressed in keys and descriptions. Individually, orientations of phyllaries vary from reflexed through spreading to appressed (often, within an involucre, outer phyllaries are ± reflexed and inner phyllaries are ± appressed). The herbaceous apices of phyllaries may be terete to flat and subulate to acuminate or acute, and vary from looped (coiled through ca. 270–400+ degrees), hooked (bent ± like a crozier through ± 180+ degrees), patent (bent at ± 90 degrees), or ± recurved or arcuate (sometimes incurved) to straight. An outer phyllary may be reflexed and have a looped, hooked, patent, recurved, or straight tip; an inner phyllary may be appressed and have a looped to hooked or recurved to straight tip; etc. The resin glands on the apices are usually circular, sometimes linear.

Cypselae of grindelias differ markedly from ovaries as seen at flowering. Cypselae are usually whitish or stramineous, sometimes brownish, grayish, reddish, or yellowish. They are usually ± compressed and ± ellipsoid to obovoid, sometimes 3–4-angled and ± reniform or rounded-prismatic. They are usually ± continuously variable in color, shape, size, and/or ornamentation within heads; sometimes they are ± dimorphic within heads, the outer differing from the inner in color, shape, size, and/or ornamentation. Cypselae that are 3- or 4-angled may have the angles ± thickened or ribbed. Apices of cypselae may be knobby (1–4 bumps or toothlike projections), coronate (a ± pronounced ridge), or smooth (rounded to ± truncate, not ornamented). Faces of cypselae may be smooth, striate (finely longitudinally nerved), ribbed, furrowed, or ± rugose (bumpy to tuberculate or with longitudinal and transverse fissures, grooves, or wrinkles).

Pappus elements are usually subulate scales (greatest width about 3 times thickness), setiform awns (greatest width about 2 times thickness), or bristles (width about equal to thickness) and are usually falling (± persistent subulate scales or setiform awns subtended by bristles in Grindelia ciliata). They may be ± straight or contorted to curled and may be smooth or barbellulate to barbellate; they were described as “entire” or “serrulate” to “setulose” by J. A. Steyermark (1934b) and others.

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