Hazardia squarrosa
Sawtooth goldenbush (Hazardia squarrosa) is a southern California native that might be mistaken for the similarly named goldenbush (Isocoma menziesii) except for the odd yellow flowers that look like flowering pine cones and the sharply pointed, holly-like leaves. Both species of goldenbush are late summer bloomers, providing an important nectar source after most flowers have gone to seed.
The Kumeyaay boiled this plant and bathed in the water to ease bodily aches and pains.
Saw-tooth bristleweed, common hazardia, Hazard's goldenbush, goldenbush
Sawtooth goldenbush is an upright or spreading, much-branched sub-shrub, usually less than three feet (1 m) high. The outer branches are covered with loose white hairs and may have a zig-zag shape, changing direction at flowering nodes. The leaves are small and oval, thickened and leathery, and they clasp the stem directly. Leaves are generally less than 1.5 inches ( 4 cm) long, flat or strongly undulated, with strong, sharp marginal teeth. The upper leaf surface is usually smooth, but the lower may have white hairs along the midvein, especially near the base.
Flower heads are born in small clusters in leaf axils spaced out along the outer portions of the branches. The involucre is elongated, to 1/2 inch (1.2 cm) in length with numerous phyllaries in eight to ten overlapping series (like shingles) and covered with short pale glandular hairs. The tip of each phyllary is acute and flares out and down, giving the unopened flower head the look of a pinecone. Flowers are bisexual disk florets about 1/2 inch (2.5 cm) long, yellow, tinged or striped with red. There is a single pistil with an inferior ovary and a two-branched stigmatic style. There are five stamens; the anthers are united into a tube around the style. Adjacent flower heads do not open at the same time and the plant never develops the color impact of the related goldenbush (Isocoma menziesii). The primary bloom time is June to Oct.1
The fruit is a small elongated one-seeded capsule, often with the brown, withered corolla persisting. The white or tawny pappus is a single row of bristles, longer than the capsule; it provides lift and dispersal in the wind. When seeds are mature, the phyllaries spread out to allow their release.
Sawtooth goldenbush is a California native found almost exclusively in the coastal strip of California, south of Monterrey Bay. It is a plant of dry, open habitats, below 4000 feet (1250 m) growing most often in chaparral and occasionally in sage scrub and grasslands.
In the Reserve, sawtooth golden bush appears to prefer the chaparral and is not often found along the trails. Several plants grow at the higher elevations along the Solana Hills access road. Specimens were collected from the Holmwood Canyon trailhead in 1991,437 but have not been found there in recent years.
Sawtooth goldenbush is a dicot angiosperm in the sunflower family, the Asteraceae.2 This is the largest family of vascular plants in the Northern Hemisphere.143 “Flowers” of Asteraceae are made up of one or both of two types of flowers (florets): symmetrical disk florets and strapped-shaped ray florets. These are crowded onto a common base (receptacle), and together are often assumed to be a single flower, which we call a flower head.11,44,49
Many other Asteraceae are common in the Reserve; these include bush sunflower (Encelia californica), coyote brush (Baccharis pilularis), California sagebrush (Artemisia californica) and the closely related goldenbush (Isocoma menziesii).
The genus Hazardia was formerly included within the large genus Haplopappus.189 There is one other species of Hazardia in the Reserve: the endangered Orcutt’s goldenbush (H. orcuttii), which has been planted on Stonebridge Mesa .
Three varieties of sawtooth goldenbush have been described.2 Ours is variety grindelioides.48
Haplopappus squarrosa, Pyrrocoma grindelioides
Sawtooth goldenbush is one of a few plants in the Reserve that flower in the fall. This strategy reduces competition for pollinating insects. However, there are associated costs: sawtooth goldenbush must survive the hot dry summer. Its leaves have many of the features for restricting transpiration that are seen in typical chaparral species.36,39,174 They are small, thick and leathery. Surface hairs further protect them from sun and wind. In addition, larger spring leaves are replaced by smaller summer leaves. One study determined the surface area of spring leaves to be five to eight times larger than the surface area of the summer leaves.6
However, there is a cost for restricting transpiration. Water loss from plants occurs during the exchange of gasses (carbon dioxide and oxygen) necessary for photosynthesis; any restriction of transpiration reduces this gas exchange and the rate of photosynthesis. Thus fall bloomers in climates with summer drought have traded rapid growth and seed production for drought tolerance and the chance of more successful pollination and seed set in the fall.
The Latin name for sawtooth goldenbush, Hazardia squarrosa, suggests something dangerous, possibly something square shaped. The truth, of course, is different. The genus was named for Barclay Hazard, an amateur botanist who owned a ranch near Santa Barbara in the latter part of the 1800s. According to the Santa Barbara Daily Independent, April 9, 1887:440
“An interesting fact was mentioned, that Prof. Greene of California University, had named a new genus
of plants . . . in honor of Mr. Barclay Hazard of this city, in consideration of the assistance rendered during the botanical excursions on Mare Island during last year. It was the same gentleman who introduced the tree Lyonothamnus asplenifolia to science, a tree known only from Santa Cruz Island.”
The species name, squarrosa is a Latin word meaning “scaly” or “rough” and refers to the texture of the herbage.
