Doug's Mountain Journal
A Chronicle of Natural History on San Bruno Mountain
Doug Allshouse has been writing his seasonal Mountain Journal for many years. We are very pleased to share his reflections on the natural history of the Mountain. Together with David Nelson, he wrote San Bruno Mountain: A Guide to the Flora and Fauna. The book was published by Heyday Books in November 2022 and can be purchased here.
Autumn 2023
So the poison oak lamented, “Sorry I’m late, did I miss anything?” And the coyote bush, the coffee berry, and the lizard tail answered, “How would we know, we all slept in.” Being late was the theme this year and the real culprit was the chilly weather that started in late 2022 and really persisted throughout this year. Poison oak generally begins turning red in late June along the Bog Trail, but the roots didn’t start calling for the chlorophyll until late August and September. And even then, the fireworks that this plant generally produces completely disappointed. I’m sure that I wasn’t the only one to notice.
There is an argument to be made that, because this past rainy season was the wettest in the last ten years, it was responsible for the lateness. Anyone who spent time observing the creeks in Buckeye and Owl Canyons this spring and summer noticed that the underground springs didn’t give up when summer came along. A hillside section in mid-Buckeye Canyon that had 40 feet of soil washed out was still wet to six feet above the creek bed around summertime. That was a sure sign that the copious amount of groundwater was still settling.
Newton’s Third Law is “For every action in nature there is an equal and opposite reaction”. It probably could be rewritten this year as “For every late wildflower show there is an equally early rain season.” We had a day of rain in late August and storms in September through November. A storm in mid-November produced 1.55 inches over five days. We seem to be in a pattern where lazy low-pressure systems stall off the Pacific Northwest shores and nothing else comes to move them along. The caveat is that the systems were squarely-aimed at Portland and Seattle and we had to settle for scraps.
A late September morning walk around the Bog Trail revealed a new population of sneezeweed (Helenium puberulum). The disc flower heads are roughly spherical with tiny yellow ray flowers at the base of the head. At maturity the ray flowers fall off creating a brownish ball generally at the end of a naked stem. The common name refers to the appearance of the flower head sneezing away the stem leaves. This is a plant that loves some moisture and I first saw it years ago on the portion of the Summit Trail that parallels Colma Creek. In the bog it has set up shop in a major drainage that begins along the upper portion of the Day Camp Road from runoff that collects in a drainage box further down the road. From there it feeds a stream that runs under the Old Guadalupe Trail and the upper Bog Trail and runs across the lower Bog Trail and finally into Colma Creek near the Parkway. This area is the wettest during the winter months and recently supported a small population of Santa Barbara sedge (Carex barbarae), which is quite rare on the Mountain. There is still a fairly large population of slough sedge (Carex obnupta). The Ohlone used the roots of sedges for sewing fiber and to make baskets.
A couple of years ago David Nelson and I noticed that giant chain fern (Woodwardia fimbriata) had disappeared from the creek in Buckeye Canyon , Summer Seep on Radio Road, and a hidden bog within a willow grove on the Bog Trail. In a clever and lazy twist on the genus Woodwardia we refer to these ferns as woodies. Chain fern is the largest fern that is native to North America with fronds growing to two meters tall. The common name comes from the shape of the large sori (located on the underside of the frond), which are oval and arranged like the links of a chain. They also prefer constant water and shade so our hunch was that they winked out due to a few dry winters. From 2019 to 2021 we received 25.6 inches of rain, and if we had gotten just average rainfall for those three years, we would have expected 40 to 48 inches of rain.
David became consumed with creating a method to grow these majestic ferns from their spores so the mission was to locate some healthy woodies and eventually collect spores for reproduction. We discovered the mother lode on Guadalupe Creek at the base of Nine Fern Rock. The rocky outcrop got its name from a photograph taken over fifty years ago of nine botanically-inspired people, each holding a different fern. At that time there were nine species of ferns identified on the Mountain: western chain fern, bracken fern, wood fern, western sword fern, California polypody, leather fern, California maidenhair fern, goldback fern, and western lady fern. I left out the scientific names since ferns generally have commonly-accepted common names. In our years of wandering the nooks and crannies of the Mountain we discovered two more, coffee fern and fragile fern. We have noticed a potential plethora of fragile fern in several places, and that is an exciting occurrence. The good news is that David’s work is paying dividends and the Mission Blue Nursery will be growing them.
As autumn comes to an end on the four days before the winter solstice, a healthy low-pressure cell finally made landfall. In what was largely a coastal event, we managed to receive 3.47 inches of rain boosting our seasonal total to 7.70 inches. We are slightly ahead of last year, however, the last five days of December 2022 produced 7.86 inches of rain and caused major mudslides in the canyons around Brisbane. January through March 2023 produced 20.33 inches of rain on 53 days of precipitation. That has not happened in the ten years of my keeping records. I’ll be happy with something close to an average rain year; twenty to twenty-four inches will suit me just fine, and maybe a slightly warmer winter. I don’t want to wait too long for wildflowers in 2024.
See you on the Mountain