Greene’s Tuctoria

Greene’s tuctoria is endemic to vernal pools. The seeds germinate underwater approximately 2 months after an initial rain event fills the pool. The species is much less tolerant of inundation than similar species, and the plants will die if late spring rains refill pools that had previously dried up. Greene’s tuctoria is an annual plant, so it dies at the end of the summer after dropping its seeds.

Greene’s tuctoria is an annual plant, so it germinates during the rainy season and then dies at the end of the following summer after dropping its seeds.

Greene’s tuctoria flowers from May to July, with peak flowering from June to July. The species is primarily wind pollinated, but pollen is probably not carried long distances between populations. Local seed dispersal is by water, which breaks up the inflorescences. Populations of Greene’s tuctoria can vary greatly from year to year, with some extant localities not appearing during dry years and appearing the next year, under more favorable rainfall conditions, with plants numbering in the thousands. Optimum germination occurs about 2 months after being covered with water when the seed is exposed to light and anaerobic conditions.

Greene’s tuctoria is dependent on vernal pools for survival. Greene’s tuctoria has been reported in 10 counties, including Shasta, Tehama, Butte, Glenn, San Joaquin, Stanislaus, Madera, Merced, Fresno and Tulare.

Greene’s tuctoria has a pith-filled stem, lacks distinct leaf sheaths and excretes a sticky substance. Greene’s tuctoria is typically found along the margins of deeper vernal pools instead of in the deeper portions of the pools.