- Author: Christy Morgan
- Posted by: Guy B Kyser
South American spongeplant (Limnobium laevigatum) is a free-floating, freshwater aquatic plant that has been introduced to the Sacramento-San Joaquin Delta. Spongeplant can propagate sexually through seed production and asexually through the development of stolons that produce new plants. This vegetative growth results in floating mats of plants that can fragment and spread with the water current.
Between August 2017 and March 2018, two studies were completed to determine the growth potential of South American spongeplant at different temperatures. These studies were designed to investigate how changes in the Delta's water temperature may affect the species' ability to proliferate and spread.
Dr. Mohsen Mesgaran, who joined the Weed Science Group this year as our weed ecophysiologist, found this plant growing on the research farm at UC Davis.
African spiderflower is a summer annual broadleaf plant in the caper family (Cleomaceae), growing up to 3 ft tall and wide. The flowers are white, somewhat tubular, with long red-to-orange stamens (see photos below). Interestingly, African spiderflower plants have three types of flowers - male, female, and hermaphroditic.
We have no idea how this plant got here. It is native to Africa, where the leaves are used as a vegetable; it is now widespread and invasive in many tropical to subtropical parts of the world. The USDA
- Author: John Madsen
- Posted by: Guy B Kyser
The Delta Region Areawide Aquatic Weed Project (DRAAWP) was represented by two presentations to the 15th International Symposium of Aquatic Plants, held February 18-23 2018 in Queenstown, New Zealand. “Quantitative techniques for assessing changes in distribution and abundance of aquatic plants after management” was presented by John Madsen, and “Improving aquatic plant management in the California Sacramento-San Joaquin Delta” by David Bubenheim. These two presentations were among the 75 presentations and dozen posters during the Symposium, held every three years. Presenters from Europe, Asia, North America, Australia, and New Zealand presented research on aquatic plant biology, ecology, and...
Saharan mustard is originally from the Mediterranean. It was introduced to California where it became a weed, particularly in the dryer parts of the state. Livestock can be poisoned by Saharan mustard if they are kept in fields that have little else to eat but Saharan mustard. Signs of toxicity include “colic, diarrhea, excessive salivation, and thyroid enlargement” (DiTomaso, J.M., G.B. Kyser et al. 2013). Saharan mustard can also increase fire hazard.
Saharan mustard has been documented in eastern San Benito County on Panoche Road; in western Fresno County; in Monterey County at Fort Hunter Liggett; and in San Luis Obispo County it is concentrated near Morrow Bay and north of Santa Maria, but has been...
- Author: Guy B Kyser
This article from Science discusses a new species of crayfish (not just recently discovered, but an actual new species) that is self-cloning and highly invasive. It's not a weed, but it acts like one...