Other Common Names:
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
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:
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
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.