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|Family: Asteraceae (Compositae)||View Description||Dichotomous Key|
|Genus: Dittrichia||View Description||Dichotomous Key|
|Species:||View Description||Dichotomous Key|
Dittrichia viscosa (L.) Greuter
Habit: Pl erect, 4--13 dm. Stem: generally 1--many, from near base, branched, woody. Leaf: cauline 4--6 cm, 6--13 mm wide, lanceolate to oblanceolate, teeth few--many on proximal, +- 0 on distal. Inflorescence: peduncle 7--12 mm; involucre 6--8 mm. Ray Flower: 12--18. Disk Flower: 25--40; corolla 6--7.5 mm. Fruit: +- 2 mm; pappus bristles 15--20, 4--6 mm. Chromosomes: 2n=18.
Ecology: roadsides, disturbed places, creeksides; Elevation: +- 43 m. Bioregional Distribution: CCo/ScV (sw of I-80/I-680 interchange), expected elsewhere; Distribution Outside California: native to Mediterranean Basin. Flowering Time: Sep--Nov Note: In North America, collected in ballast on east coast in late 1800s but then not again until 2014, in California, where it is reportedly scheduled for eradication; in Australia, on list of 28 most threatening non-native plants, even though considered only to be in early stages of establishment there.
Unabridged Note: In Australia, on the Alert List for Environmental Weeds, comprising "28 non-native plants that threaten biodiversity and cause other environmental damage", even though considered only to be in early stages of establishment there. In southwestern Western Australia: said to be spreading rapidly by seed along roadsides and walking trails in areas of medium to high rainfall; seed said to be spread by flotation (air or water) and also during soil movement (e.g. in road making or road grading, which also might have been the case in the California establishment) or when attached to machinery; and is said to be more reliant on moisture than Dittrichia graveolens, even having been collected from disturbed areas in swamps (http://www.environment.gov.au/cgi-bin/biodiversity/invasive/weeds/weeddetails.pl?taxon_id=7115).
eFlora Treatment Author: Thomas J. Rosatti
Jepson Online Interchange
Previous taxon: Dittrichia graveolens
Next taxon: Dyssodia
Citation for this treatment: Thomas J. Rosatti 2017. Dittrichia viscosa, in Jepson Flora Project (eds.) Jepson eFlora, Revision 2, http://ucjeps.berkeley.edu/eflora/eflora_display.php?tid=2456, accessed on March 29, 2017.
Citation for the whole project: Jepson Flora Project (eds.) 2017. Jepson eFlora, http://ucjeps.berkeley.edu/eflora/, accessed on March 29, 2017.