''Eryngium racemosum'' is a rare species of flowering plant in the family

Apiaceae Apiaceae or Umbelliferae is a family of mostly aromatic flowering plants named after the type genus ''Apium'' and commonly known as the celery, carrot or parsley family, or simply as umbellifers. It is the 16th-largest family of flowering plants ...

known by the common name delta eryngo, or delta button celery.

Distribution

It is

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...

California California is a U.S. state, state in the Western United States, located along the West Coast of the United States, Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the List of states and territori ...

, where it is known from the Sacramento-San Joaquin River Delta region of the Central Valley up to the rise of the

Sierra Nevada foothills :''See Sierra Nevada for general information about the mountain range in the United States.'' The ecology of the Sierra Nevada, located in the U.S. states of California and Nevada, is diverse and complex: the plants and animals are a significant ...

. It is a plant of vernally wet and flooded areas near the waterways of the valley, habitat which has been altered and in some areas eliminated by human activity. It is also a member of the flora in the rare alkali sink habitat of the delta.Species Account
Bay-Delta Conservation Plan
. November 7, 2008. The plant has no federal listing but it is listed as an

endangered species An endangered species is a species that is very likely to become extinct in the near future, either worldwide or in a particular political jurisdiction. Endangered species may be at risk due to factors such as habitat loss, poaching and inv ...

on the California state level. There are 26 reported occurrences of the plant, but several of these have been

extirpated Local extinction, also known as extirpation, refers to a species (or other taxon) of plant or animal that ceases to exist in a chosen geographic area of study, though it still exists elsewhere. Local extinctions are contrasted with global extinct ...

. Threats to the species include

habitat destruction Habitat destruction (also termed habitat loss and habitat reduction) is the process by which a natural habitat becomes incapable of supporting its native species. The organisms that previously inhabited the site are displaced or dead, thereby ...

via alteration of water regimes and water diversion, changes to waterways by

dredging Dredging is the excavation of material from a water environment. Possible reasons for dredging include improving existing water features; reshaping land and water features to alter drainage, navigability, and commercial use; constructing da ...

and other maintenance activities, conversion of land to

agriculture Agriculture or farming is the practice of cultivating plants and livestock. Agriculture was the key development in the rise of sedentary human civilization, whereby farming of domesticated species created food surpluses that enabled people to ...

, and non-native plant species. The plant relies on the seasonal flooding that would occur naturally in the delta; this flooding is strictly contained and prevented today.

Description

''Eryngium racemosum'' is a mostly prostrate perennial herb with a slender, branching stem spreading to a maximum length near half a meter. The stem may root at nodes that come in contact with moist soil. The serrated or lobed leaves have blades a few centimeters long and are borne on longer petioles. The

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. Morphologically, it is the modified part of the shoot of seed plants where flowers are formed o ...

is a raceme of rounded or oval flower heads, each surrounded by five long, narrow, spiny

bract In botany, a bract is a modified or specialized leaf, especially one associated with a reproductive structure such as a flower, inflorescence axis or cone scale. Bracts are usually different from foliage leaves. They may be smaller, larger, or of ...

s. The flowers in the head bloom in white or purple-tinged petals in June through September.

References

External links

Calflora Database: ''Eryngium racemosum'' (Delta button celery, Delta eryngo)Jepson eFlora (TJM2) treatment of ''Eryngium racemosum''USDA Plants Profile for ''Eryngium racemosum'' (delta eryngo)UC CalPhotos gallery of ''Eryngium racemosum'' (delta eryngo)
{{Taxonbar, from=Q5396306 racemosum Endemic flora of California Natural history of the Central Valley (California)