The third “sticky” plant in our east pasture (Modoc County CA) is curlytop gumweed (Grindelia squarrosa). Another common name, rosinweed, is well deserved because the leaves and flower bracts are dotted with glands that exude a material that is very tacky. Like Chilean tarweed, curlytop gumweed has a strong scent that remains on clothing and hands. The aroma is often described as rosin-like and unpleasant, however, as with tarweed, I like the odor.
Another member of the sunflower family, the yellow flower is composed of ray and disk flowers. The flower head is hemispheric with curved bracts surrounding the flower. These curved bracts are a key to the identification of curlytop gumweed. The basal leaves are lance-shaped while the stem leaves are alternate, stalkless and often clasp the reddish stem. Curlytop gumweed grows from a fibrous, branching taproot. Reproduction is by seeds.
This biennial or short-lived perennial is native to and can be found in all of North America except the extreme southeastern states and Alaska. It inhabits pastures, rangelands, roadsides and other waste areas where it sometimes forms pure stands. Curlytop gumweed is extremely drought resistant and increases in numbers after periods of dryness. Range managers often use curly gumweed as an indicator of overgrazing. Noxious weed or wildflower? It depends on your point of view.
In areas where there is naturally occurring selenium in the soil curlytop gumweed accumulates selenium and can be poisonous to livestock. In other areas curlytop gumweed is harmless. However, livestock find this gumweed unpalatable and will not eat it unless starved.
Native Americans made a tea from fresh or dried curlytop gumweed leaves, which they used to treat asthma, bronchitis, colic and skin rashes. Even today extracts of curlytop gumweed are used by modern herbalists.
Meriwether Lewis collected curlytop gumweed on his westward explorations. Curlytop gumweed gets its genus name from David Grindel (1776-1836), a Russian botanist. The species name means scaly or rough in Latin and could refer to its flower bracts or to the general gumminess of the plant.
Catchfly, Chilean tarweed and curlytop gumweed – the three “stickies”. I like all three plants!