''Stellaria irrigua'' is a species of flowering plant in the family

Caryophyllaceae Caryophyllaceae, commonly called the pink family or carnation family, is a family of flowering plants. It is included in the dicotyledon order Caryophyllales in the APG III system, alongside 33 other families, including Amaranthaceae, Cactacea ...

known by the common names umbrella starwort and umbellate starwort. It is native to western North America from

Alaska Alaska ( ; russian: Аляска, Alyaska; ale, Alax̂sxax̂; ; ems, Alas'kaaq; Yup'ik: ''Alaskaq''; tli, Anáaski) is a state located in the Western United States on the northwest extremity of North America. A semi-exclave of the U.S., ...

and north-western Canada to the south-western United States, as well as parts of Asia, including

Siberia Siberia ( ; rus, Сибирь, r=Sibir', p=sʲɪˈbʲirʲ, a=Ru-Сибирь.ogg) is an extensive geographical region, constituting all of North Asia, from the Ural Mountains in the west to the Pacific Ocean in the east. It has been a part of ...

. It grows in subalpine and

alpine climate Alpine climate is the typical weather (climate) for elevations above the tree line, where trees fail to grow due to cold. This climate is also referred to as a mountain climate or highland climate. Definition There are multiple definitions of ...

s in mountain forests and riverbanks. It is a rhizomatous

perennial A perennial plant or simply perennial is a plant that lives more than two years. The term ('' per-'' + '' -ennial'', "through the years") is often used to differentiate a plant from shorter-lived annuals and biennials. The term is also wide ...

herb In general use, herbs are a widely distributed and widespread group of plants, excluding vegetables and other plants consumed for macronutrients, with savory or aromatic properties that are used for flavoring and garnishing food, for medicinal ...

producing a slender prostrate stem up to about 20 centimeters long, sometimes forming clumps or mats. The stem is lined with pairs of oval leaves each up to about 2 centimeters long. 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 an

umbel In botany, an umbel is an inflorescence that consists of a number of short flower stalks (called pedicels) that spread from a common point, somewhat like umbrella ribs. The word was coined in botanical usage in the 1590s, from Latin ''umbella'' "p ...

-shaped array of several flowers each on an arching or erect

pedicel Pedicle or pedicel may refer to: Human anatomy *Pedicle of vertebral arch, the segment between the transverse process and the vertebral body, and is often used as a radiographic marker and entry point in vertebroplasty and kyphoplasty procedures ...

s. The flower has five pointed green

sepal A sepal () is a part of the flower of angiosperms (flowering plants). Usually green, sepals typically function as protection for the flower in bud, and often as support for the petals when in bloom., p. 106 The term ''sepalum'' was coined b ...

s each no more than 3 millimeters long. There are occasionally tiny white petals within the calyx of sepals, but these are generally absent.

References

External links

Jepson Manual TreatmentFlora of North AmericaPhoto gallery
irrigua Flora of Subarctic America Flora of Western Canada Flora of the Northwestern United States Flora of the Southwestern United States Flora of the South-Central United States Flora without expected TNC conservation status Taxa named by Alexander von Bunge {{Caryophyllaceae-stub