A Flora of the Vascular Plants
of The Sea Ranch

by George B. Snyder
Revised September, 2000

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• Catalogue of Vascular Plants

The plants listed herein are contained within the area included in The Sea Ranch Amended Precise Development Plan of December, 1981, except the Southern and Northern Timber Production Zones that were sold. This leaves The Sea Ranch with about 4000 acres. Cultivated plants around homes, the lodge and the golf course are not included.

Nomenclature and organization of families, genera and species follow The Jepson Manual, Higher Plants of California, 1993. With very few exceptions all of the taxa were checked in the field. Plants listed as present by others but not observed by the author are not included.

An attempt has been made to specify "likelihood to encounter" by placing each taxa in one of four categories: rare, occasional, common and abundant, with modifications where appropriate. These ratings apply to The Sea Ranch only. A plant may be abundant on The Sea Ranch but rare in California. It will be rated abundant.

The Sea Ranch (TSR) occupies the northernmost 16 kilometers of the Sonoma County coastline. It is bounded on the west by the ocean, on the east by the first forested ridge of the outer Coast Ranges, on the north by Gualala Point Regional Park and on the south by private ranch and timber lands. Its width varies from 0.2 - 1.6 kilometers. Highway One bisects the community in a north-south direction.

There is hardly a square meter of TSR that has not been disturbed by man's activities. Cattle ranching, crop farming and logging started about the middle of the 19th century. The principal ranching activity was cattle grazing with sheep replacing the cattle in later years. The last sheep were removed from the ranch in 1968. Logging removed all of the old-growth redwoods by the early part of this century, and the present forested area is dominated by second-growth Sequoia sempervirens and Pseudotsuga menziesii. The Central Timber Production Zone (CTPZ) was cut over in 1990-92 before it was purchased by TSRA. Most of the marketable trees were removed and the understory severely damaged. In 1964 Castle and Cooke purchased Del Mar Ranch and developed it as a recreational subdivision. Homesites have been situated such that large areas of meadow and forest have been preserved as permanent open space.

In spite of its hard life TSR supports a diverse flora. With few exceptions it has reestablished itself without direct aid from man. The far-sighted principle of "living lightly on the land" established by the developer and the allocation of about 1/2 of the land as commons have fostered the recovery. This flora lists 482 species, subspecies and varieties, representing 81 families and 284 genera. 146 species (31%) are introduced.

Nine taxa are included in the "CNPS Inventory of Rare and Endangered Vascular Plants of California":

The 4000 acres, although not a large study area, has a diverse population due to the number of different natural plant communities that occur. These communities are:

1. Ocean Strand: Small beaches in the coves at the base of the bluffs. These are above the normal high-tide line and are often wetted by fresh water intermittent streams spilling off of the Coastal Terrace or by seeps from the bluff faces.

Characteristic Species: Cakile maritima, Ambrosia chamissonis, Distichlis spicata, Scirpus cernus and Potentilla anserina ssp. pacifica.

2. Ocean Bluffs: For most of the length of TSR rocky bluffs rise steeply from sea level to the Coastal Terrace. Heights vary considerably with the average being about 12 meters. The faces have many seeps and are cut by canyons of the creeks that spill off of the terrace.

Characteristic Species: Plantago maritima, Dudleya farinosa, Grindelia stricta var. platyphylla, Angelica hendersonii, Eriogonum latifolium and in the wet places Mimulus guttatus and Epilobium ciliatum ssp. watsonii.

3. Sand Dunes: There are two small areas of dunes. Both have been stabilized with Ammophila arenaria which has almost totally excluded all other species. At Walk-On-Beach Castilleja wightii is represented by some large shrubby specimens on the lee side of the dunes and Mainthemum dilatatum is present in a wet depression at the inland edge.

4. Headlands and Lip of Bluffs: This ocean edge of the Coastal Terrace, exposed to strong winds and salt spray, supports a low-growing community that is a combination of ocean bluff and grassland species. Forbs and low shrubs are visually dominant and produce a carpet of color in the spring.

Characteristic Species: Angelica hendersonii, Eschscholzia californica, Lupinus variicolor, Calochortus tolmiei, Allium dichlamydeum, Armeria maritima ssp. californica, Erigeron glaucus, Grindelia stricta var. platyphylla, Lasthenia californica and Ceanothus griseus var. horizontalis.

5. Coastal Terrace: The two youngest marine terraces have weathered into a single, gently sloping terrace that lies between the bluff top and Highway One. It is mostly grassland with some patches of coastal scrub. Three of its special features are the riparian corridors, the cypress hedgerows and the pine plantations. This meadowland is the location of most of the home building and golf course expansion currently underway. At build-out about half of it will remain as commons or restricted areas.

Characteristic Species: The two most abundant grasses are Anthozanthum odoratum and Holcus lanatus. Other common grasses are Avena barbata, Briza maxima and Lolium multiflorum. Wet depressions are usually populated with tussocks of Calamagrostis nutkaensis which form a distinctive grassland unit. Campanula californica, Oenanthe sarmentosa, Juncus effusus var. pacificus and Carex obnupta are typically found in association with the Calamagrostis. Forbs scattered through the grassland include Hypochaeris radicata, Calystegia purpurata ssp. saxicola, Geranium dissectum, Iris douglasiana and Sisurinchium bellum. The scrub areas support Lupinus arboreus, Heracleum lanatum, Baccharis pilularis var. consanguienea, Rubus ursinus and Rosa nutkana var. nutkana.

Numerous streams originating in the forest cross the terrace and spill over the bluff edge. Vegetation in the riparian corridors varies from woodland in Salal Creek Canyon to forbs only along some of the smaller intermittent streams. Woody species predominate, including Myrica californica, Rhododendron occidentale, Rhamnus californica ssp. californica, Salix laevigata, S. lasiolepis, Alnus oregona and Rubus parviflorus. Among the forbs are Carex obnupta, Juncus effusus var. pacificus, Veratrum fimbriatum, Vicia gigantea and Oenanthe sarmentosa. The developer planted large numbers of Pinus muricata and P. radiata above and below Highway One. These dense stands are known as the Pine Plantations. In the period of 1916 to 1919 the "Signature Hedgerows" of Cupressus macrocarpa were planted to break the prevailing northwest winds and improve conditions for the cattle.

6. Redwood-Fir Forest: To the east of Highway One the terrain slopes up rather steeply to TSR eastern border along the first forested ridge of the outer Coast Ranges. The grasslands extend east of Highway One intermittently and in a few places patches of meadow extend to the ridge. Conversely the forest extends down slope in the canyons of the water courses and actually across Highway One at some of the larger continuous streams. The forest is dominated by second-growth Sequoia sempervirens and Pseudotsuga menziesii. The sequoias are almost 100% stump sprouts of the tress cut ±100 years ago. Marketable size trees were harvested in the CTPZ in 1990-92 and stump sprouts are already starting the cycle over again. Lithocarpus densifloras var. densifloras is common in the understory. Pinus muricata is common on the poor, drier soil of the ridge and it and Arbutus menziesii are pioneers in extending the forest down slope along the water courses. Abies grandis is found on the lower west facing slopes. Understory shrubs include Gaultheria shallon, Vaccinium ovatum and Rhododendron macrophyllum. Polystichum munitum and Oxalis oregana are abundant on the Redwood forest floor.

Last Updated: 03/19/07