Saving San Diego’s Rarest Plant Species

Share on FacebookTweet about this on TwitterPin on Pinterest

San Diego Zoo Global’s Native Plant Seed Bank has been working hard this year as a member of the California Plant Rescue partnership (CaPR). Coordinated by the Center for Plant Conservation (CPC), CaPR is a collaboration among many of the botanical gardens, seed banks, and botanical organizations in California to conserve the rarest and most threatened plant species throughout the state and northwestern Baja California. The purpose of CaPR is the long-term conservation of wild populations of these species through seed banking and fieldwork. At the Native Plant Seed Bank, this has meant working with the City of San Diego and other land managers to gain access and find these rare populations, monitor the blooming cycle, and eventually make a responsible seed collection. We spent many long days in the field, hiking in search of flowering populations that would hopefully produce viable seeds.
We had great success this year, making 14 different seed collections from very rare plant populations. The following seed collections are a few we are most excited about:

The San Diego golden Bloomeria clevelandii is a beautiful, rare bulb. It lives in just a very small strip of habitat in San Diego County and part of northern Baja California, Mexico—and nowhere else on Earth! We were able to find a large population in the Los Peñasquitos Canyon area and another around the Otay Lakes.

The San Diego golden star Bloomeria clevelandii is a beautiful, rare bulb. It lives in just a very small strip of habitat in San Diego County and part of northern Baja California, Mexico—and nowhere else on Earth! We were able to find a large population in the Los Peñasquitos Canyon area and another around the Otay Lakes.

is found in small pockets around the county, generally in vernal pool type habitat. We made a seed collection from a population in the Los Peñasquitos Canyon area

Brodiaea orcuttii is found in small pockets around the county, generally in vernal pool type habitat. We made a seed collection from a population in the Los Peñasquitos Canyon area.

caption

Dudleya brevifolia is a tiny plant that only exists in dry sandy bluffs near the coast. We made a great collection of these tiny seeds from the Carmel Mountain area. The plants are so small that making this collection required the use of kneepads and tiny nail scissors!

Corethrogyne filaginifolia var. linifolia is known as the Del Mar Sand Aster. This particular variety is limited to coastal areas centered around Del Mar and nowhere else. We made two collections in different locations.

Corethrogyne filaginifolia var. linifolia is known as the Del Mar sand aster. This particular variety is limited to coastal areas centered around Del Mar and nowhere else. We made two collections in different locations.

Comarostaphylis diversifolia ssp. diversifolia is known as Summer Holly because of its bright red berries which are ripe in the mid to late summer months.

Comarostaphylis diversifolia ssp. diversifolia is known as summer holly because of its bright red berries which are ripe in the mid to late summer months. (Photo: Stacy Anderson, SDZG)

There are very few populations know to still exist. This population was found in the Otay Mountains, existing on very rugged, rocky terrain. Photo: Stacy Anderson

There are very few summer holly populations known to still exist. This population was found in the Otay Mountains, existing on very rugged, rocky terrain. (Photo: Stacy Anderson, SDZG)

Monardella stoneana is a beautiful plant in the mint family. It grows in steep stony washes on the mountains that straddle the US-Mexico boarder. There are only 6 known occurrences in the world. We made seed collections from populations in the Otay Mountains this year.

Monardella stoneana is a beautiful plant in the mint family. It grows in steep stony washes on the mountains that straddle the US-Mexico border. There are only six known occurrences in the world. We made seed collections from populations in the Otay Mountains this year. (Photo: Stacy Anderson, SDZG)

Other particularly rare seed collections were made from the coast wallflower Erysimum am mophilum  and  Lakeside lilac Ceanothus cyaneus.

It is hard to overstate the importance of these seed collections. These are populations of species that are at risk of disappearing in the wild—species that occur in our backyard, and while not as charismatic as many endangered animal species, they too may not escape extinction without our help. Seeds have the remarkable ability to go into a dormant state when frozen, and remain alive for hundreds, possibly thousands of years. We can freeze and save thousands of living individuals in the Native Plant Seed Bank using relatively little space. Seeds saved today might become the only survivors of some of these plant populations. They might, one day, be all that is left. It is the amazing ability of these seeds to hibernate for years that allows us to work on the front line in our fight against extinction in the globally rare, threatened plant community in San Diego County.

Joe Davitt is a Schlum Fellow in Plant Conservation at the San Diego Zoo Institute for Conservation Research.

Add a comment

Due to the increased volume on our many social media channels, we are unable to respond to all comments or questions. Comments are now posted automatically but may be removed if deemed inappropriate according to the San Diego Zoo Global Blog Comment Policy.