The inflorescence of Canyon Liveforever (prob. Dudleya cymosa).
From a run at Sage Ranch Park on June 2, 2006.
Related post: Chalk Liveforever.
Category Archives: nature|wildflowers
Twiggy Wreath Plant?
An ant forages among the florets of a wreath plant.
I’ve run past wreath plants thousands of times in the chaparral of local open space areas. At a glance, the nondescript wiry brown plant isn’t very appealing. But it’s one of a few plants you’ll see blooming in the chaparral in the Fall, so on a run this last November I took a closer look. This revealed a lavender-tinged composite flower that is anything but mundane. And, as I was to discover, a case of probable mistaken identity, and an example of one of the ways new species occur.
Three field guides in my library identify the plant pictured above as Twiggy Wreath Plant (Stephanomeria virgata). But, as discussed by Tom Chester, there is some confusion regarding it’s characteristics and identity. It could be the case that many Southern California plants previously identified as S. virgata may actually be San Diego Wreath Plant (S. diegensis), including those in the Santa Monica Mountains.
The plants are very similar, but according to the identification key for the genus Stephanomeria in the Jepson Manual can be distinguished by a groove along the length of a seed (achene). This isn’t something easily done in the field. The achenes are so tiny that they are best seen in a strong loupe or a low power microscope. Wayne’s World Volume 9 (Number 3) Fall 2000 has some photographs of the achenes and groove.
So why are S. virgata and S. diegensis so similar? The genetic relationship of various members of the genus Stephanomeria has been researched and it appears likely that S. diegensis is a relatively recent species that resulted from a natural cross of S. exigua and S. virgata.
The photograph of the foraging ant was taken on a run at Sage Ranch on November 5, 2006. Based on examination of some achenes from wreath plants in the area, the plant is probably Stephanomeria diegensis.
Technical papers:
Genetic Evidence for the Hybrid Origin of the Diploid Plant Stephanomeria diegensis
G. P. Gallez, L. D. Gottlieb
Evolution, Vol. 36, No. 6 (Nov., 1982), pp. 1158-1167
Phylogeny of Stephanomeria and related genera (compositae–lactuceae) based on analysis of 18S–26S nuclear rDNA ITS and ETS sequences
Joongku Lee, Bruce G. Baldwin and L. D. Gottlieb
American Journal of Botany. 2002;89:160-168
Chaparral Mallow
Chaparral Mallow (Malacothamnus fasciculatus) from a run at Sage Ranch Park on November 2, 2006.
Ladybug Bivi
On a chilly October morning, following a cold night at 9400 ft., a Seven-spotted Lady Beetle is slow to move from her bivouac amid the blossoms of a Rabbitbrush.
The photo is from the North Backbone Trail Revisited hike and run.
Christmas Berry on the Garapito Loop
A photo of the berries of Toyon (Heteromeles arbutifolia) taken on the Garapito Loop trail run on Thanksgiving Day. Also called Christmas berry, the plant is protected by a California law.
The Garapito Loop is a pleasant 7.5 mile figure eight course that starts at the south end of Reseda Blvd. at Marvin Braude Mulholland Gateway Park, goes up to near Eagle Rock via Fire Road #30 and Eagle Rock Fire Road, and then returns via the Garapito and Bent Arrow Trails. Here’s a Google Earth image of a GPS trace of the route and a 3D, interactive view of a slightly longer variation of the loop that visits Eagle Rock.
Also see: Ferns Along the Garapito Trail
Milk Thistle Seed Heads
A native of the Mediterranean, Milk Thistle is an invasive weed that appears to be increasingly profuse in roadside areas of Upper Las Virgenes Canyon Open Space Preserve. Generally considered detrimental in the wild, the plant has been used medicinally for at least 2000 years, and is cultivated in Texas, Canada and Argentina.
According to the Washington State Noxious Weed Control Board, Milk Thistle (Silybum marianum) produces about 190 seeds per flower, and over 6000 seeds per plant. Dense stands are reported to produce 1.4 million viable seeds and four tons of vegetation per acre! Here is a closer look at an individual Milk Thistle seed.
This photograph was taken on a run at Ahmanson Ranch on July 13, 2006. The posting Convoluted includes a photograph of the white-veined leaf, and a photo of a dense stand of Milk Thistle in Las Virgenes Canyon. Additional information regarding Milk Thistle, including its history, laboratory studies, clinical trials, and adverse effects can be found in the National Cancer Institute’s Milk Thistle (PDQ®).