Mather Field Vernal Pools


 
Castilleja campestris
© Ken Davis
common name

Field Owl's-clover

 
scientific name

Castilleja campestris

 
family

Scrophulariaceae (figwort)

 
habitat

vernal pools

 
size

plant 4 to 7 inches tall,
flower 6 to 8 mm across

 
fun facts

Field Owl's Clover often supports the parasitic plant Vernal Pool Dodder (Cuscuta howelliana) which is the yellowish string-like plant in this photo.

   
description

Member of the figwort family. The flowers are long tubes with three inflated  (balloon-like) lobes near the top. In Field Owl's-clover the inflated sacks are bright yellow.

The other owl's-clovers all have colorful, multi-lobed bracts. Only Field Owl's-clover has simple, green, leaf-like bracts.

 
life cycle

Field Owl's-clover is an annual. It usually germinates after the water in the pools has become very shallow and warm. It blooms from April to May and can be one of the dominant species in a pool.

 
ecology

Most owl's-clovers require very specific environmental conditions for successful germination and growth. Some years there will be very few plants or even none, while other years there might be millions! Very little is know about how the owl's-clovers are pollinated.

 
investigate

Try watching a Field Owl's-clover for a while to find out if any insects visit it. Be sure to look for small crawling insects as well as the flying ones. Do you think Field Owl's-clover is pollinated by insects?

 
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