North Coast Semaphore Grass

​Today we are going to look at a rare plant, the North Coast Semaphore Grass, Plueropogon hooverianus. This is a perennial grass that is found in grasslands and riparian woodlands. It grows to a height of 1 to 1.6 meters and blooms from April to June. This year, due to the heat and dryness we have experienced, it is blooming a bit more sporadically and not as robust compared to the previous year. Perhaps the rain this week will prolong its blooming season into June.

The leaf blade is soft to the touch and is sword-shaped at the tip. Its light green color makes it stand out especially when there is an abundance of it. The base of the plant is maroon, which is good for identifying it before it flowers. The cylindrical spikelets which contain the flowers hang sideways off the stem. They are four and one half centimeters long, resembling railway semaphore signals. I look forward to seeing its long inflorescence waving in the breeze every year.

Why is North Coast Semaphore Grass (NCSG) important and how does it relate to the mitigation land? This plant is a rare California endemic, meaning it is found only in California and within that, its range is limited to three counties – Marin, Sonoma, and Mendocino. There are no other existing populations. Because of this it has been listed as a California Rare Plant rank 1B.1 seriously endangered, a State rank of S2, imperiled, and a Global rank G2 also imperiled.

During the bypass construction an incidental take permit was granted to mitigate the impact on NCSG. More than 5000 plants were relocated, and ideal areas were set aside for rehabilitation of habitat and enhancement of North Coast Semaphore Grass. It is an important part of our work for the Mendocino County Resource Conservation District on the mitigation lands. Invasive plants and grazing are carefully monitored for the health of this rare plant. Part of the plan to increase the population of NCSG on mitigation lands includes harvesting and planting seeds and opening up more areas for it to grow by removing debris and competing invasive plants.

We are fortunate to have this and our other rare endangered plant, Limnanthes bakeri, growing in Little Lake Valley.


Some information obtained from Geri Hulse-Stephens