Ericameria nauseosa, commonly known as chamisa, rubber rabbitbrush, and gray rabbitbrush, is a shrub in the sunflower family (Aster) found in the arid regions of western North America.
Ericameria nauseosa
Volunteer chamisa in the landscaping of the post office in Crestone, Colorado
Flower heads, each with five individual flowers. Most of the flower heads in the cluster of heads were removed for this image.
Blooms of the decorative rabbitbrush used at the Crestone post office.
A pseudanthium is an inflorescence that resembles a flower. The word is sometimes used for other structures that are neither a true flower nor a true inflorescence. Examples of pseudanthia include flower heads, composite flowers, or capitula, which are special types of inflorescences in which anything from a small cluster to hundreds or sometimes thousands of flowers are grouped together to form a single flower-like structure. Pseudanthia take various forms. The real flowers are generally small and often greatly reduced, but the pseudanthium itself can sometimes be quite large.
What appear to be "petals" of an individual flower, are actually each individual complete ray flowers, and at the center is a dense pack of individual tiny disc flowers. Because the collection has the overall appearance of a single flower, the collection of flowers in the head of this sunflower is called a pseudanthium or a composite.
Peace Lily (Spathiphyllum cochlearispathum) pseudanthium
compressed pseudanthia of Lepironia articulata
Euphorbia caput-medusae 01
