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Friends of the Regional Parks Botanic Garden

No Thursday plant sales
May 2014

We're preparing for our
annual spring plant sale on
April 19, 2014




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The garden is located at the intersection of Wildcat Canyon Road and South Park Drive in Tilden Regional Park near Berkeley, CA


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February 2014

The Brodiaeas: A Diverse Group of Beautiful Bulbs for the Garden

From the first explorations in California, a series of beautiful spring-flowering bulbs came to light, and over the years new species were added to the list until at present, we recognize close to 40 species in what we now call the Brodiaea complex. This series of closely related genera is centered in California but extends throughout the West. During those first several decades of discovery, the name Brodiaea was applied differently by different people, and many separate genera were recognized from time to time, creating a large tally of confusing names. It finally took the efforts of Robert Hoover in the mid-1900s to sort through and elucidate the definitions that we still follow today.

What is the Brodiaea complex? Spring-flowering bulbs (actually corms) that now belong to their own family, Themidaceae, including the genera Triteleia, Brodiaea, Dichelostemma, and Bloomeria (and a few more that for our purposes are not significant) comprise this group. All share basal, grass-like to strap-shaped leaves, a naked flowering stalk (scape), and an umbel of colorful flowers with six tepals (sepals and petals that look alike), three or six stamens, and a three-chambered ovary that ripens into a many-seeded capsule. In most species, the tepals are joined into a short to long tube at the base of the flower.

To further clarify, here are some ways to recognize the genera:

Brodiaea has waxy, often blue or purple tepals; three fertile stamens producing pollen and alternating with three sterile stamens that look like a set of internal petals; and flowers borne on a stiff scape. Brodiaeas live mostly in grasslands and mostly at low elevations.

Dichelostemma has non-waxy tepals in blue, purple, pink, or red; three fertile stamens (one exception) backed by appendages; and an often crooked or twisted flower scape. This genus lives in grasslands, woodlands, deserts, and even the edges of forests. The umbels are usually crowded and contain more flowers than the umbels in Brodiaea.

Triteleia has non-waxy tepals in blue, purple, white, or yellow and six fertile stamens in flowers borne on a stiff scape. Triteleias live in grasslands, meadows, woodlands, and even sometimes on the edges of temporary wetlands, and some species grow at high elevations.

Bloomeria is similar in most respects to Triteleia, but with yellow flowers only and tepals that are separate and don’t form a tube. Bloomerias mostly live in grasslands or open woodlands.

For the garden, the Brodiaea complex provides easy spring color with minimal care. The typical species send up leaves sometime in winter after the first few soaking rains, followed by flowering stalks from early March into July, depending on species and climatic conditions. The flowers last for two to three weeks and then set seed. About a month after bloom, the plants die back to the ground, resting underground the remainder of the late spring or summer into fall and thereby avoiding the hot, dry conditions so prevalent in most California plant communities during that time.

In order to grow brodiaeas, plant the bulbs just as you would tulips or daffodils in the fall, let the rains get the roots and leaves started, and add some supplemental water during dry periods in the winter to keep things moving along. Think of using a variety of different species to keep the floral pageant going, starting with blue dicks (Dichelostemma capitatum) in early spring, moving on in mid-spring to Ithuriel’s spear (Triteleia laxa) and elegant brodiaea (Brodiaea elegans) in late spring, finishing perhaps with long-rayed brodiaea (Triteleia peduncularis) and California brodiaea (Brodiaea californica) in late June to early July.

Most gardeners remove the dried flower heads in order to prevent formation of seed, as seed set takes food away from next year’s corm (but allowing seed to form can be a fun way of propagating the plants). While many bulbs resent summer water during their dormancy, the brodiaeas are less fussy as long as they’re planted in a well-drained soil that isn’t watered heavily. (Other sensitive bulbs often must be lifted and stored where summer water is used.)

Brodiaeas multiply readily from offsets or cormlets produced by the parent plant, and propagation from seed is easy but takes three to four years before a blooming plant is established. 

Here is a brief description of a few outstanding species:


Brodiaea californica

Brodiaea californica, California brodiaea: The most robust and floriferous of the species, with flower scapes reaching over a foot high and beautiful pink-purple flowers late in the season

B. elegans, elegant brodiaea: A shorter plant that blooms in May to early June with clear blue flowers.


Dichelostemma capitatum, blue dicks: Highly variable plant from six inches to almost three feet tall, with tight clusters of blue or purple flowers surrounded by dark purple bracts, blooming at the start of spring.

Dichelostemma capitatum
D. volubile

D. volubile, snake lily or twining brodiaea: A curious plant with twining, vinelike stems up to three feet long and small pink flowers in mid-spring.

D. multiflorum, wild hyacinth: A robust plant growing up to a foot high, with large clusters of pink-purple flowers in mid-spring.


D. ida-maia, firecracker brodiaea: A one-foot-tall plant with umbels of nodding, tubular, bright red flowers trimmed with green tepals and blooming in mid- to late spring. Likes part-day shade.

D. ida-maia
Triteleia laxa

Triteleia laxa, Ithuriel's spear: A highly variable plant that grows to a foot or more tall with open clusters of funnel-shaped blue or purple flowers from mid- to late spring, depending on the variety.

T. ixioides, pretty face brodiaea: A variable species from three to 10 inches high, with flat, yellow, star-like flowers from mid-spring to early summer, depending on the source.

T. ixioides

T. hyacinthina, white or milk brodiaea: Grows to a foot high, with large clusters of snowy white to purple-tinted flowers in mid-spring.

T. peduncularis, long-rayed brodiaea: This plant is often over a foot high, with a very open umbel of funnel-shaped white to purple-tinted flowers in summer.


Bloomeria crocea

Bloomeria crocea, golden stars: Similar overall to pretty face brodiaea, but its flowers are often a deeper yellow. Blooms in late spring.

By trying a few of these, you’ll add beautiful color to a meadow or woodland garden, but finding these plants or corms in nurseries is sometimes difficult. Come to the Regional Parks Botanic Garden’s spring sale (this year it’s on April 19, 10 am – 3 pm), where we offer several of these species.

—Glenn Keator 

Note:  Glenn Keator is teaching a class at the Botanic Garden on April 26 & 27, "Learning the Brodiaea Clan and Their Uses in the Garden".  If you are interested see the link in the Upcoming Classes section below for details.

Wayne Roderick Lectures:
Added lecture on Saturday,
March 1, 10:30 am

Exploring Guadalupe Island, Mexico: The remarkable recovery of the island’s flora

Speaker: Bart O’Brien, the garden’s new director
This lecture is free, but seating is limited, so come very early to save a chair!

Biological Soil Crusts of Joshua Tree National Park

Date/Time: Saturday, March 8, 9 am–5 pm, and
Sunday, March 9, 9 am– 4 pm
Meet at: Oasis Visitor Center, Joshua Tree National Park
Fee: $100 Joshua Tree National Park Association (JTNPA) or Partners in Nature Education (PINE) member, $110 non-member
Instructors: Nicole Pietrasiak, PhD, and Kerry Knudsen
Hike Level: Easy to Moderate
Offered by: the Desert Institute

The desert floor may look like dirt and sand, but it is full of living microscopic organisms vital to the park’s ecosystem. Many of these organisms live in biological highly active soil crusts that cover the first inch of the desert soil surface. In this field class Nicole Pietrasiak and Kerry Knudsen will introduce biological soil crusts with an emphasis on soil algae and lichens. Participants will study the secret life of these microscopic organisms as they demystify this thin layer of soil. Nicole and Kerry will discuss the components of crusts such as cyanobacteria (one of the oldest known life forms on earth), green algae, diatoms, bacteria, fungi, lichens and mosses. The instructors will also discuss why these organisms are important. During the lab session, participants will see the biodiversity of the park’s crusts up close through two different types of microscopes. The second day, the class will go into the field to identify and assess the conditions of some of the algal and lichen soil crusts found in Joshua Tree National Park.

Download the course outline:  Biological Soil Crusts of JTNP Outline – Spg2014

Click here for a Lichen Flora Inventory of Joshua Tree National Park by Kerry Knudsen



Upcoming Classes

A click here will take you to a fuller description of the class as well as the class registration form
Sunday, February 23, 10 am–2:30 pm Manzanitas of San Bruno Mountain

Space Available

Saturday, March 29, 9:30 am–12:30 pm Drawing Leaves and Plants Space Available
Saturday, April 5, 10 am–3 pm Botanizing California: Spring Flowers After the 2013 Fire on Mount Diablo

Class is Full

Saturday & Sunday, April 26 & 27, 10 am–2:30 pm Learning the Brodiaea Clan and Their Uses in the Garden Space Available
Saturday, May 10, 9 am–5 pm Botanizing California: The Special Habitats of the Santa Cruz Mountains Space Available
Sunday, June 8, 10 am–1 pm Creating Hypertufa Containers Space Available
Saturday, June 21, 10:30 am–2:30 pm Butterflies for Beginners Space Available
Illustration/Photo Credits

©Glenn Keator