Practical ecological knowledge for the temperate reader.

Entire-Leaved Gumweed - Grindelia stricta



Medicinal Uses


"an extremely variable species and so has been described under a number of different names." [PCBC2004]

General Often somewhat woody at base. More or less succulent.[HNW] 15-80cm tall.[PCBC2004] nearly glabrous or with long, soft hairs. [IFBC][E-flora]
Lifecycle Perennial.[HNW]
Flowers Yellow ray flowers.[HNW] 10-35 or more [IFBC][E-flora], single to several on leafy stalks.[WildPNW] 10-35 or more; involucral bracts slightly or moderately sticky.[IFBC][E-flora]
Fruits Achenes.[HNW] "compressed, scarcely nerved; pappus of 2-several deciduous, firm bristles."[IFBC][E-flora]
Leaves Leaves fleshy, oblong to lanceolate, broad, entire or sharply toothed[HNW] and "resin-dotted. basal leaves lance-shaped, up to 40 cm long; stem leaves alternate, stalkless and often clasping at their bases." [PCBC2004]
Stem Stout, several, somewhat hairy.[WildPNW]
Root Taproot.[PCBC2004]
Properties Grindelia Spp. Resinous, sticks to teeth, pleasant. [Tilgner HMHE]
Habitat Salt marshes, tidal flats[HNW], wet meadows[WildPNW], dry beaches and coastal bluffs.[IFBC][E-flora]
Range Common in coastal BC; S to N CA. [IFBC][E-flora]
Status Native [E-flora]
Notes A highly variable species. "Douglas (1995) concluded that it was best to recognize only one environmentally variable species."[IFBC] [E-flora]

The genus Grindelia includes some twenty-five species, six or eight of which are found in South America and the remainder occurring in the United States west of the Mississippi. They are coarse perennial or biennial herbs, being occasionally shrub-like. Most, if not all, of the species produce a resinous exudation on the stem and leaves and especially on the flower-heads.[Remington USD20]

The New World Grindelia, with approximately 60 species, belongs to the tribe Astereae, subtribe Soladiginae in the large family Asteraceae. This genus occurs in western North America from southern Mexico north to Canada and Alaska, and from the Great Plains to the Pacific coast. In South America, it occurs at high elevations in the southern part of the continent. Although the greatest concentration of species (i.e. 22) is in the xerophytic sites of the south-western USA, only three species are widespread in this area: G. camporum, G. aphanactis, and G. squarrosa." "...only 14 species from the large genus Grindelia have been chemically investigated." [Wickens PAL]

A resinous exudation is common to the various species of the genus, being most abundant in the flower-heads, and it is possible that medicinal properties are common to the genus. [Sayre MM-6]

Gum plants, including Grindelia camporum, G. humilis, G. robusta, and G. squarrosa, were used by Native Americans to treat bronchial problems, skin irritations caused by poison ivy, and other complaints (Vogel 1970). Resin from G. camporum still provides a valuable remedy for bronchial asthma (Chevallier 1996). Both an antispasmodic and expectorant, it helps relax muscles of the smaller bronchial passages and clear congested mucus. It may also desensitize nerve endings in the bronchial tree and slow the heart rate, both leading to easier breathing. Moreover, this resin has been used to treat whooping cough, hay fever, and cystitis. [Langenheim PR]

Grindelia camporum- Great Valley Gum Plant [California][PSW]

Grindelia robusta (Gum Plant)[WUM Henkel]

Gum used medicinally.[Ethchumash] Given in full and frequent doses as a specific for permanent relief of asthmatic breathing. Used for chronic spasmodic bronchial coughs, in chronic bronchitis, and in combination with other specific agents for whooping cough. Use to treat hay fever, poison ivy, insect bites and indolent old ulcers.[Ellingwood]

Grindelia squarrosa(Pursh) Dunal curly-cup gumweed (curlycup gumweed)

[South central & South east B.C.][E-flora] Scaly grindelia (G. squarrosa) "has a wider distribution than the gum plant [G. robusta], being quite common on the plains and prairies from the Saskatchewan to Minnesota, south to Texas and Mexico, and westward to California...This species is very similar to the gum plant, with the exception that it is smaller and does not have the gummy apearance of thr former." [WUM Henkel]

Grindelia squarrosa
Seed + Pericarp
Mass of 1,000, g: 0.7
Oil (petroleum ether), % on dry wt.: 20.0
Iodine value, % J2: 138.0
Saponification value, mg KOH: 186.0 [LLCEOPS]

G. robusta & G. squarrosa; Externally and locally the drug is sedative and mildly astringent. Synergetic with motor depressants and chiefly eliminated by the kidneys. The drug is feebly toxic but can be a gastro-intestinal irritant. The fluid extract should be well diluted when applied externally and the extract is incompatible with aqueous preparations.[Butler,1908]


G. robusta Essential Oil

a-pinene 10.3% Camphene 1.0% Verbenene 0.5% B-pinene 1.2%
p-cimene 0.5% Limonene 4.3% y-terpinene 0.1% Cis-pinen-2-ol 0.1%
p-cymene 0.2% Terpinolene trace a-campholenal 1.5% Nopinone 0.3%
Camphor 0.7% Trans-pinocarveol 7.0% Pinocarvone 2.6% Isoborneol trace
Borneol 15.2% p-cymen-8-ol 2.2% Bornyl isovalerate 1.3% Y-cadinene 0.3%
d-cadinene 0.2% Germacrene-B 0.2% Terpinen-4-ol t Myrtenal 1.6%
Methyl cavicol trace Myrtenol 1.7% Verbenone 2.6% Trans-carveol 1.3%
Cis-carveol 0.1% Carvone 1.0% Perillaaldehyde 0.5% (E)-anethole 0.7%
Bornyl acetate 4.5% d-elemene 0.1% a-cubebene trace a-copaene 0.2%
a-humulene 0.3% y-muurolene 0.1% GermacreneD 0.3% B-selinene 3.2%
Spathulenol 0.5% Humulene-oxide 0.5% T-cadinol 1.5% B-Eudesmol 4.1%
Calamenol 0.4% [Fraternale,2007]

Crude Resin Content
* G. camporum - Natural stands (10.3-15.6%) - Cultivated stands (7.9-9.7%, 8.8-11.2%) [Ravetta et al.]
* G. stricta var. platyphylla - Natural stands (9.6-10.1%) - Cultivated stands (8.9%) [Ravetta et al.]
* G. stricta var. stricta - Natural stands (5.2%) - Culivated stands (3.3%) [Ravetta et al.]
* G. chiloensis - Natural stands (16.1-37.1%) - Cultivated stands (10.4-14.6%) [Ravetta et al.]

"With this study we have shown that there are indeed two distinct types of resins within the selected North American species of Grindelia. In addition, collections from the Rocky Mountain area displayed considerably more variation in resin acid composition than the collections from the Pacific Coast states. These results suggest that the differences observed in quantitative resin acid composition represent differences in genotype rather than in growing conditions of the plants." Timmermann lists G. stricta ssp. stricta under the 'squarrosa subgroup' of resin acid composition , along with species such as G. camporum, G. robusta, G. squarrosa and others. [Timmermann1987]

G. stricta subsp. stricta was found to contain 12.9% and 10.8% crude resin, with 7.4% and 5.3% resin acids. [Timmermann1987]

Grindelia, commonly called gum weed because the plants are usually tacky or sticky to the touch, has been studied in detail. The tackiness is from the mixed terpenoid and flavonoid resin, not true gum as the implied by the name (Chapters 1 and 7). Apparently, Grindelia is characterized by a diversity of resin glands, and G. camporum has two types of resin-secreting tissues (Figure 3-8): (1) multicellular trichomes in shallow pits on the surface of stems, leaves, and phyllaries (bracts surrounding the flower heads) and (2) canals in the leaf mesophyll and stem cortex (Hoffmann et al. 1984). Resinous trichomes are most abundant on the involucres of the flower heads, densely distributed on leaves, but sparse on stems. Accordingly, resin constituted 20% of dry weight of flower heads, 14% of leaves, and only 2% of stems (Hoffmann and McLaughlin 1986). Furthermore, because resin was easily extracted from Grindelia flower heads compared to the stem, Hoffmann and McLaughlin concluded that most resin is produced by trichomes rather than in the few internal canals. Thus flower heads are the most important source of resin for use, with leaves secondary (Chapter 10). [Langenheim PR]





1. "Naval stores" is the generic term for a large class of chemicals, including turpentine, fatty acids, rosins recovered from tall oil, gum and wood rosin, and their derivatives. Rosin, which is a complex mixture of diterpene resin acids, is used widely in diverse industrial applications".[Hoffmann,1986]

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