Paper Flower
Psilostrophe cooperi
Watercolor from live specimen observed in the Sonoran Desert of
Arizona.
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FLOWERS: Bright or pale yellow flowers appear mid to late spring. After
blooming the ray florets remain, bleach whitish, and rustle like bits of paper
in the breeze. A member of the Asteraceae, the flowers are borne in heads with
each flower producing one seed or achene; two achenes are shown enlarged, one
with the ray corolla attached.
SHRUB: Low shrub usu. less than one
meter tall is slightly woody about the base.
RANGE: Mid elevations in the Arizona Sonoran Desert. More common near
Tucson than in Phoenix area.
LEAVES: Nearly linear and often quite silvery due to abundance of
whitish hairs. The foliage is highly aromatic due to the presence of
psilotropin and related terpenes. These compounds deter feeding by many
mammalian herbivores and many insects, but not all.
UNARMED.
The sharply contrasting pattern of this moth larva might work to conceal it under bright desert sunshine as it feeds on the leaves of paper flower. Harquahala Mountains, La Paz Co., Arizona, USA. March 2012. Rearing a larva to adult would make identification to species easier.
The moth will be digested from the inside as the spider feeds. It could well be that this moth is the adult of the larva shown feeding on the leaves. It could also be that this moth is an important pollinator. Thus the spider could be both friend and foe to the paper flower plant. The spider is a sit-and-wait predator, a Desert Crab Spider (Misumenops deserti).
At elevations above 600 m this plant makes an excellent contribution to xeriscape gardens. A high resolution photo of a spectacular blooming plant in the foothills of Four Peaks east of Phoenix can be seen on Flickr.