Euphorbia hooveri
Encyclopedia
Euphorbia hooveri is a species of euphorb known by the common names Hoover's sandmat and Hoover's spurge. It is endemic to California
, where it grows in the rare vernal pool
s of the Central Valley. Due to the elimination of most of its habitat, it became a federally listed threatened species in 1997.
This is an annual herb forming flat mats of thin, hairless stems. The stems are ringed with pairs of tiny, minutely toothed round leaves, each gray-green leaf blade only a few millimeters wide. The inflorescence
is a cyathium
only two millimeters wide. The cyathium is made up of flat, white appendages surrounding a single minute female flower within a cluster of several male flowers. The female flower develops into a spherical fruit containing white seed. The seeds germinate
once the pool evaporates with the arrival of summer.
The vernal pools of the Central Valley have nearly disappeared as the land there has been consumed for agriculture
and development. This plant occurs in the center of a vernal pool, usually in the deepest part that becomes a mudflat as the pool dries. The plant grows from the cracks in the drying mud. Another threat to the species is invasive plant species
that move into its habitat.
California
California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...
, where it grows in the rare vernal pool
Vernal pool
Vernal pools, also called vernal ponds or ephemeral pools, are temporary pools of water. They are usually devoid of fish, and thus allow the safe development of natal amphibian and insect species...
s of the Central Valley. Due to the elimination of most of its habitat, it became a federally listed threatened species in 1997.
This is an annual herb forming flat mats of thin, hairless stems. The stems are ringed with pairs of tiny, minutely toothed round leaves, each gray-green leaf blade only a few millimeters wide. The inflorescence
Inflorescence
An inflorescence is a group or cluster of flowers arranged on a stem that is composed of a main branch or a complicated arrangement of branches. Strictly, it is the part of the shoot of seed plants where flowers are formed and which is accordingly modified...
is a cyathium
Cyathium
A cyathium is one of the specialised pseudanthia forming the inflorescence of plants in the genus Euphorbia . A cyathium consists of:...
only two millimeters wide. The cyathium is made up of flat, white appendages surrounding a single minute female flower within a cluster of several male flowers. The female flower develops into a spherical fruit containing white seed. The seeds germinate
Germination
Germination is the process in which a plant or fungus emerges from a seed or spore, respectively, and begins growth. The most common example of germination is the sprouting of a seedling from a seed of an angiosperm or gymnosperm. However the growth of a sporeling from a spore, for example the...
once the pool evaporates with the arrival of summer.
The vernal pools of the Central Valley have nearly disappeared as the land there has been consumed for agriculture
Agriculture
Agriculture is the cultivation of animals, plants, fungi and other life forms for food, fiber, and other products used to sustain life. Agriculture was the key implement in the rise of sedentary human civilization, whereby farming of domesticated species created food surpluses that nurtured the...
and development. This plant occurs in the center of a vernal pool, usually in the deepest part that becomes a mudflat as the pool dries. The plant grows from the cracks in the drying mud. Another threat to the species is invasive plant species
Invasive species
"Invasive species", or invasive exotics, is a nomenclature term and categorization phrase used for flora and fauna, and for specific restoration-preservation processes in native habitats, with several definitions....
that move into its habitat.