Category Archives: nature

Sage Sculpture

A study of a dessicated stalk of hummingbird sage (Salvia spathacea) at Sage Ranch Park in Southern California.

It’s growth exhausted, this dessicated stalk of hummingbird sage (Salvia spathacea) is a relic of Southern California’s 2005-2006 rain season. A robust member of the mint family, the flowering stalks typically grow to a height of 1-3 ft., but in this case the full stalk reached about 4 ft. The 2006-2007 rain season was too dry to produce flowering stalks in this area.

From a run at Sage Ranch Park on August 22, 2007.

Related post: Dealing with Drought

Department of Coyote Comportment

Coyote path at Ahmanson Ranch.

With little new growth this Spring and Summer, coyote paths at Ahmanson Ranch have become so well worn that several have recently been posted with “Restoration Area – Please Keep Out” signs. Whether the canny coyotes will choose to cooperate remains to be seen.

Note: Ahmanson Ranch was acquired as open space in part to protect several sensitive species and their habitats. Some (human) use trails have evolved and “Restoration Area – Please Keep Out” signs are a reminder that the area is a preserve.

From a recent run at Upper Las Virgenes Canyon Open Space Preserve (formerly Ahmanson Ranch).

Related post: Trickster

Leaf Vein Networks

Study of a leaf of a Fremont cottonwood (Populus fremontii) along Las Virgenes Creek in Upper Las Virgenes Canyon Open Space Preserve.

Who hasn’t pondered the intriguing network formed by the interconnected veins of a leaf? Like many apparently complex self-organized structures, there is a recognizable pattern, but the basis of the pattern is difficult to grasp.

Remarkably, research published in 2002 (S. Bohn et al., Phys. Rev. E, June 2002.) found that there is a simple relationship governing the angles between vein segments in the leaves of dicotyledons, and that this relationship is universal. The study also found that the observed vein angles can be reproduced using a simple force model.

Numerical analysis of leaf scans revealed that the angles between vein segments are directly related to the thickness of the segments. When the vein sizes are similar, the connection appears to form a three-way junction with the angle between the veins about 120 degrees. If the vein sizes are dissimilar, with one much larger than the other, the smaller vein joins the larger at about a 90 degree angle.

The photograph is of a leaf of a Fremont cottonwood (Populus fremontii) along Las Virgenes Creek in Upper Las Virgenes Canyon Open Space Preserve. It was taken on a run from the Victory trailhead on May 16, 2007.

Milkweed Bug Nymphs

Large milkweed bug nymphs on a narrow-leaved milkweed seed pod.

The bright orange-red coloration of these immature large milkweed bugs (Oncopeltus fasciatus) is a warning to predators that they taste bad. Like monarch butterflies, they concentrate foul-tasting compounds from the narrow-leaf milkweed (Asclepias fascicularis) in their bodies.

Following several instars (molts), the nymph is transformed into the adult insect.

The photograph is from a run at Sage Ranch on July 23, 2007.

Wally Waldron Limber Pine

A grizzled guardian of the San Gabriel Mountains, the Wally Waldron Tree stands defiantly astride an airy, rock strewn ridge, just below the summit of 9399 ft. Mt. Baden-Powell.

A grizzled guardian of the San Gabriel Mountains, the Wally Waldron Tree stands defiantly astride an airy, rock strewn ridge, just below the summit of 9399 ft. Mt. Baden-Powell.

Perched on the brink of the mountain’s precipitous southeast face, the weather-sculpted Limber Pine is at an elevation and in an environment similar to the 4000+ yr. old White Mountain Bristlecone Pines. Burnished and hardened, the tree’s huge, gnarled roots anchor it firmly to the mountain, helping it to resist the whims of weather and time. The tree is estimated to be 1500 years old.

We had stopped to visit the tree part way through an approximately 23.5 mile loop from Islip Saddle. Our route had descended to South Fork Campground (4560′), before climbing back up to Vincent Gap and Mt. Baden-Powell. In a few minutes we would continue to Baden-Powell’s summit, and from there follow the PCT along the crest back to Islip Saddle. Here’s a Google Earth image and Google Earth KMZ file of a GPS trace of the loop.

Water Notes: The little stream on the Manzanita Trail about 1.5 miles from Vincent Gap was still running. The flow from Little Jimmy Spring was lower than normal, but still very reasonable. We did not detour to Lamil Spring.

Related posts: Vincent Gap – Little Jimmy Spring Out & Back, Complications, Heat Wave