OregonFlora: Grindelia hirsutula vs. Grindelia decumbens

	Grindelia hirsutula	Grindelia decumbens
	hairy gumweed
Habit	Plants perennial.
Stems	erect, 30–75 cm, glabrous to sparsely strigose.
Basal leaves	similar to cauline but larger and more strongly oblanceolate; up to 13 × 1.7 cm, usually present at flowering.
Cauline leaves	oblong to oblanceolate, 1–9 × 0.3–0.8 cm, bases narrowly cordate to cuneate; margins entire to sparsely toothed; tips rounded or obtuse, sometimes apiculate; surfaces glabrous and glandular-punctate; distal reduced in length, usually ± same width throughout.
Involucres	6–12 × 9–21 mm.
Ray florets	10–24; rays 7–9 × 1.8–2.4 mm.
Disc florets	5.5–6.5 mm.
Phyllaries	in 4–5 series, glabrous, tips of outer erect to recurved 90°, tips of inner usually erect.
Fruits	4.5–5 × 1.5–2 mm, white or light tan; crowns 0–0.2 mm; pappus awns ~5 mm.
Heads	3–15 per main stem; borne singly, radiate; peduncles 0.2–14 cm.
2n	=12, 24.

	Grindelia hirsutula	Grindelia decumbens
Distribution	[WildflowerSearch map] [BONAP county map]	[BONAP county map]
Discussion	Open serpentine areas. Flowering Jul–Sep. 0–1600 m. Sisk. CA; British Columbia. Native. Oregon plants of this species are distinct from other Grindelia in the state due to their rounded, mostly untoothed leaves, phyllaries that are usually erect, and distribution in serpentine areas in the southwestern part of the state. They are also distinct from the G. hirsutula from California, which have larger, usually tomentose heads and toothed leaves.
Source	Flora of Oregon, volume 2, page 275 Abigail (Abby) Moore
Sibling taxa	G. integrifolia, G. integrifolia x Grindelia nana, G. integrifolia x Grindelia nana var. nana, G. nana, G. squarrosa, G. stricta	G. hirsutula, G. integrifolia, G. integrifolia x Grindelia nana, G. integrifolia x Grindelia nana var. nana, G. nana, G. squarrosa, G. stricta
Synonyms	Grindelia camporum, Grindelia hirsutula var. davyi
Web links	Local floras: BC, CA, OR, WA Local Web sites: CalFlora, CalPhotos, Flora NW, PNW Herbaria WildflowerSearch iNaturalist (observations) USDA Plants Database LBJ Wildflower Center SEINet Plants of the World Online Encyclopedia of Life Wikipedia Google Image Search	Local Web sites: Flora NW, PNW Herbaria WildflowerSearch iNaturalist (observations) USDA Plants Database LBJ Wildflower Center SEINet Plants of the World Online Encyclopedia of Life Wikipedia Google Image Search

Grindelia decumbens

hairy gumweed

Habit

Plants perennial.

Stems

erect, 30–75 cm, glabrous to sparsely strigose.

Basal leaves

similar to cauline but larger and more strongly oblanceolate; up to 13 × 1.7 cm, usually present at flowering.

Cauline leaves

oblong to oblanceolate, 1–9 × 0.3–0.8 cm, bases narrowly cordate to cuneate;

margins entire to sparsely toothed;

tips rounded or obtuse, sometimes apiculate;

surfaces glabrous and glandular-punctate;

distal reduced in length, usually ± same width throughout.

Involucres

6–12 × 9–21 mm.

Ray florets

10–24;

rays 7–9 × 1.8–2.4 mm.

Disc florets

5.5–6.5 mm.

Phyllaries

in 4–5 series, glabrous, tips of outer erect to recurved 90°, tips of inner usually erect.

Fruits

4.5–5 × 1.5–2 mm, white or light tan; crowns 0–0.2 mm;

pappus awns ~5 mm.

Heads

3–15 per main stem; borne singly, radiate;

peduncles 0.2–14 cm.

=12, 24.

Grindelia decumbens

Distribution

[WildflowerSearch map]

[BONAP county map]

Discussion

Open serpentine areas. Flowering Jul–Sep. 0–1600 m. Sisk. CA; British Columbia. Native.

Oregon plants of this species are distinct from other Grindelia in the state due to their rounded, mostly untoothed leaves, phyllaries that are usually erect, and distribution in serpentine areas in the southwestern part of the state. They are also distinct from the G. hirsutula from California, which have larger, usually tomentose heads and toothed leaves.

Source

Flora of Oregon, volume 2, page 275
Abigail (Abby) Moore

Sibling taxa