San Marcos Vernal Pool Area 2010
Wayne's WordIndexNoteworthy PlantsTriviaLemnaceaeBiology 101BotanySearch
    Brodiaea jolonensis?      BTK In San Marcos      San Marcos Vernal Pools      Key To San Diego Brodiaeas      Brodiaea Images      Index Of Brodiaea Pages 

San Marcos Vernal Pools Spring 2010
© W.P. Armstrong 27 May 2010
Note: The Brodiaea, that I referred to as "Coastal BTK," is listed as a possible
undescribed taxon under B. jolonensis in the revised Jepson Manual II (2011)

  1. Vernal Pool in San Marcos After Rains of January 2010      
  2. B. terrestris ssp. kernensis in San Marcos in April 2010      
  3. Potted Brodiaea jolonensis Photographed in April 2010      
  4. Potted B. jolonensis cf. potted BTK from Santa Barbara      
  5. Potted BTK from Figueroa Mtn in Santa Barbara County      
  6. Brodiaeas Photographed in San Marcos on 28 May 2010      

San Marcos vernal pools photographed 25 January 2010 following heavy El Niño rains the previous week.

Asteraceae: Hesperevax sparsiflora var. sparsiflora (Erect Evax)

Hesperevax sparsiflora var. sparsiflora, a seldom seen, inconspicuous member of the sunflower family (Asteraceae) that grows in the San Marcos Vernal Pool area. The tiny heads have 5 exposed, minute disk flowers. Additional flowers are embedded in the wooly bracts below.

Hesperevax sparsiflora var. sparsiflora showing tiny head with 5 minute disk flowers (red arrow) surrounded by hairy bracts. The tiny head is only 3.8 mm in diameter compared with a U.S. penny (19 mm in diameter).

See The Size Of Penny Used In Wayne's Word Articles

Close-up view of the floral head of Hesperevax sparsiflora var. sparsiflora with 5 minute disk flowers surrounded by hairy bracts. The tiny head is only 3.8 mm in diameter. Several other immature heads can also be seen in this image.

Magnified view of the floral head of Hesperevax sparsiflora var. sparsiflora showing 5 minute disk flowers surrounded by hairy bracts. The tiny head is only 3.8 mm in diameter. Image taken through Bausch & Lomb dissecting microscope with Sony W-300.

Scrophulariaceae (Orobanchaceae): Castilleja densiflora ssp. gracilis (Owl's Clover)

Themidaceae: Brodiaea terrestris ssp. kernensis = BTK (Earth Brodiaea = Harvest Brodiaea)

Brodiaea jolonensis From Monterey County NOT San Diego County

Cut away view of Brodiaea jolonensis flower compared with U.S. penny (19 mm in diameter).

Brodiaea jolonensis has been listed incorrectly for coastal vernal pool habitats in southern California for many decades, including San Marcos, Kearny Mesa and Otay Mesa. It superficially resembles coastal populations of B. terrestris ssp. kernensis (BTK), but generally has a smaller flower and distinctive purple ovary. The perianth length (measured from attachment point at pedicel to tip of perianth segment) is generally less than 22 mm, shorter than BTK. The most obvious difference is the purple ovary, a characteristic unique to this species. I have never observed BTK with dark purple ovaries, although it may have some streaks of purple. There are a number of other characteristics that separate B. jolonensis from BTK, including taller scapes, inner perianth with fewer vascular strands and fewer chromosomes. See the table at following link.

Brodiaea jolonensis in Monterey County
Brodiaea jolonensis in San Diego County?

Brodiaea jolonensis From Monterey County Compared With BTK From Santa Barbara County

A. Brodiaea jolonensis (Monterey Co.); B. BTK (Figueroa Mtn, Santa Barbara Co.); C. BTK (San Marcos, San Diego Co.).

A. BTK from Figueroa Mtn. (Santa Barbara County); B. Brodiaea jolonensis (Monterey County). In BTK there is a distinct V-shaped notch in the connective tissue between adjacent anther sacs. In B. jolonensis the anther apices are incurved and connivent, obscuring the V-shaped notch.

Abaxial view of two stamens of Brodiaea jolonensis from Monterey County. A V-shaped notch is visible in the anther connective of the left stamen. On many flowers the anther apices were incurved and connivent, obscuring the V-shaped notch.

A. Brodiaea terrestris ssp. kernensis (BTK) from Kern County. B. BTK from San Marcos (San Diego County). C. BTK from Figueroa Mtn. (Santa Barbara County). D. Brodiaea jolonensis from Monterey County. The perianth length (measured from attachment point at pedicel to tip of perianth segment) is 25 to 30 mm for BTK and 20 mm for B. jolonensis.

Potted BTK From Figueroa Mountain in Santa Barbara County

Brodiaea terrestris ssp. kernensis from Figueroa Mtn. (Santa Barbara County) grown in San Marcos (May 2010). The corm was grown in a flower pot in heavy clay soil devived from nearby San Marcos Gabbro. Except for the white staminodes, the flowers are virtually indistinguishable from coastal populations of BTK in San Diego County. In fact, some BTK in the San Marcos vernal pool area actually have white staminodes.

BTK on Figueroa Mtn. & Gaviota Pass In Spring 2009

Brodiaeas Photographed in San Marcos Field on 28 May 2010

Themidaceae: Brodiaea filifolia (Thread-Leaf Brodiaea)


A pale Brodiaea filifolia amidst a field of blue-violet flowers.

Themidaceae: Brodiaea orcuttii (Orcutt's Brodiaea)

Themidaceae: Brodiaea terrestris ssp. kernensis (Earth Brodiaea = Harvest Brodiaea)

Liliaceae: Chlorogalum parviflorum (Small-Flower Soap Plant)

Asteraceae: Grindelia camporum var bracteosa (Gum Plant)

Asteraceae: Erigeron foliosus var foliosus (Leafy Daisy)

Poaceae: Hordeum intercedens (Bobtail Barley)

Bobtail barley (Hordeum intercedens), a native species in the vernal pool preserve adjacent to Fry's Electronics in San Marcos. The dense spikes are more slender than other naturalized (weedy) species. The spikelets are three per node like other species; however, the sterile lemma of lateral spikelets is 1.7-4.4 mm long with a short awn less than 1.2 mm. This species is similar to H. depressum which also grows in vernal pool areas and has been reported from San Diego County.

Bobtail barley (Hordeum intercedens), a native annual in vernal pools of San Marcos.

Return To San Marcos Vernal Pool Page
Return To WAYNE'S WORD Home Page
Return To NOTEWORTHY PLANTS Page
Go To Biology GEE WHIZ TRIVIA Page
Go To The LEMNACEAE ON-LINE Page