Telegraph Weed

Heterotheca grandiflora

yellow flowers on plant
Telegraph weed (Heterotheca grandiflora) is a tall, coarse annual or short-lived perennial that produces numerous yellow, daisy-like flower heads in late summer and fall. Leaves are sticky to touch and smell strongly of camphor (some think creosote) when crushed.
Telegraph weed produces two kinds of seeds. Seeds from the center of the flower head have a silky tuft of bristles that the wind may carry long distances, even into unfavorable areas. Seeds from the edge of the flower head lack the parachutes and many fall locally. These seeds have a greater chance of landing in a favorable spot and producing a new plant, but have less chance of colonizing new habitats. Thus telegraph weed “hedges its bets” ensuring continuation of local populations while also dispersing into new ones.
Other Common Names:

Description 2,4,43,59

Telegraph weed is a tall, upright annual, biennial or short-lived perennial. The main stem grows to 6 feet from a basal rosette of leaves. The stem is unbranched below, with numerous short lateral branches near the top. It is bristly with both glandular and non-glandular hairs.
The size and shape of the leaves are variable, even on a single plant. Leaves vary from less than 1 inch (2.5 cm) to more than 3 inches (8 cm) long; they are oblong or ovate. Margins are somewhat wavy and toothed. Rosette leaves have a petiole. Lower leaves have ear-like projections at their base. Leaf size and petiole length decrease upward from the base of the stem. Upper leaves lack a petiole. Leaves are soft with hairs, many of which are glandular; leaves are sticky with a strong smelling resin, resembling camphor or, to some, creosote. This pungent odor may be the best way to identify an uncertain plant.
Yellow flower heads are daisy-like, usually ½-¾ inches (10-20 mm) in diameter. The eye of the daisy consists of 20 or more yellow disk florets, each of which has both male and female reproductive parts; the surrounding corolla consists of 20-30 yellow ray florets, which are female only. The petals of fertilized ray florets curl back tightly against the edge of the flower base – making it look like a lady wearing rollers. The main bloom period is in the fall, but flower heads may be found all year.1
Telegraph weed is unusual in having two types of seeds. Seeds produced by the disk florets are elongate, less than a ¼ inch (6 mm) in length with a terminal tuft of white/tan bristles (a pappus) somewhat longer than the seed. Seeds produced from the ray florets are more triangular and lack the bristles. Seeds from the disk florets are wind dispersed and may be carried some distance from the parent plant; they germinate rapidly. Seeds from the ray florets fall close to the parent plant and germinate more slowly.47
dried out flower center
curled green leaves
yellow flower with many tiny petals

Distribution 7,8

Telegraph weed is native to California and only California. It is found throughout the state except in the northernmost and easternmost counties. It occurs in sage scrub, chaparral and woodlands below 1000 feet (300 m) especially in disturbed areas. It has recently naturalized in adjacent states, Hawaii and Australia.202

Telegraph weed is common in the Reserve, especially along trails and in open sandy places on the south side. At the Nature Center, a few plants can usually be found in the sandy wash along the north end of the boardwalk.


Telegraph weed is a dicot angiosperm in the sunflower family (Asteraceae).2,11 This is the largest family of vascular plants in the Northern Hemisphere.143 “Flowers” of Asteraceae are made up of one or both of two types of flowers (florets): symmetrical disk florets and strapped-shaped ray florets. These are crowded onto a common base (receptacle), and together are often assumed to be a single flower, which we call a flower head.11,44,49 

Other familiar Asteraceae that occur in the Reserve include California sagebrush (Artemisia californica), bush sunflower (Enceliacalifornica), and goldenbush (Isocoma menziesii).

The genus Heterotheca is characterized, in part, by having two types of seeds; the seeds produced by disk flowers have a pappus of soft bristles; the seeds produced by ray flowers are smaller and lack the pappus.

Alternate Scientific Names:

Heterotheca floribunda

Jepson eFlora Taxon Page
curled green leaves going up stem
multiple plants with yellow flowers on top
yellow flowers from multiple stems


The two types of seeds produced by telegraph weed are a survival strategy for uncertain environments.47 The parachute-bearing seeds from the disk florets are transported by the wind and are likely to be carried away from the parent plant. These seeds germinate quickly. While many will land on inhospitable soil, a few may not and these few may colonize a new area. The seeds produced by the ray florets have no parachute and fall close to the parent plant, in an environment where the parent plant has succeeded. Ray seeds are more sensitive to environmental conditions and germinate more slowly. Ray seeds ensure the continuation and expansion of the original population. Thus, telegraph weed distributes its seedlings over both space and time, a strategy which accounts for its successful colonization of disturbed areas and recent range extensions as far as Australia.46


yellow flower with many small petals
dried out flower center
plant stem topped with hairy seed pod

Human Uses

Kumeyaay used the stems of telegraph weed for lightweight construction material18 and the Luiseños for simple arrows.17 The Chumash used it as a flea repellant,15 and there is one report of a recent Kumeyaay lady using it to treat sores on her dog.18


yellow flower with many small petals
flower plants with yellow flowers
field filled with plant with yellow flowers

Interesting Facts

Telegraph weed has the dubious distinction of being one of the few California native plants classified as a weed in other parts of the world.46

The common name may come from the tall, straight stem bearing smaller branches at the top which resembles a telegraph pole, or from the plants pungent, “creosote-like” odor.23,34 It may also come from the tendency of this plant to invade disturbed areas – surely the original telegraph lines were underlined by a golden path of telegraph weed.


yellow flower with small flower petals
plant with yellow flowers

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