Astragalus jaegerianus
Encyclopedia
Astragalus jaegerianus is a rare species of milkvetch
known by the common name Lane Mountain milkvetch. The plant was named for the biologist Edmund Jaeger
, who first documented it in 1939.
, where it is known from only four populations in the vicinity of Fort Irwin
in the Mojave Desert
. It is a federally listed endangered species
.
s. In dry years the plant grows only a few centimeters long before flowering, but after abundant rain it may climb to the tops of neighboring shrubs. The leaves are 2 to 5 centimeters long and are made up of several widely spaced narrow leaflets with hairy upper surfaces.
The inflorescence
is an open array of up to 15 pale purple, dark veined flowers. Each flower is up to one centimeter in length. The flowers are insect-pollinated, with the most common pollinator being the megachilid bee
Anthidium dammersi
. The fruit is a hanging legume pod up to 2.5 centimeters long. It is hairless and dries to a leathery or thick papery texture.
Astragalus
Astragalus is a large genus of about 3,000 species of herbs and small shrubs, belonging to the legume family Fabaceae, subfamily Faboideae. The genus is native to temperate regions of the Northern Hemisphere...
known by the common name Lane Mountain milkvetch. The plant was named for the biologist Edmund Jaeger
Edmund Jaeger
Edmund Carroll Jaeger, D.Sc. was an American biologist known for his works on desert ecology. He was born in Nebraska and moved to California in 1906...
, who first documented it in 1939.
Distribution
It is endemic to northeastern San Bernardino County, CaliforniaSan Bernardino County, California
San Bernardino County is a county in the U.S. state of California. As of the 2010 census, the population was 2,035,210, up from 1,709,434 as of the 2000 census...
, where it is known from only four populations in the vicinity of Fort Irwin
Fort Irwin Military Reservation
Fort Irwin & the National Training Center is a major training area for the United States Military and is a census-designated place located in the Mojave Desert in northern San Bernardino County, California. Fort Irwin sits at an elevation of . The 2010 United States census reported Fort Irwin's...
in the Mojave Desert
Mojave Desert
The Mojave Desert occupies a significant portion of southeastern California and smaller parts of central California, southern Nevada, southwestern Utah and northwestern Arizona, in the United States...
. It is a federally listed endangered species
Endangered species
An endangered species is a population of organisms which is at risk of becoming extinct because it is either few in numbers, or threatened by changing environmental or predation parameters...
.
Description
This is a perennial herb with thin stems coated in scaly hairs. The stems reach 30 to 70 centimeters in length and grow tangled in the herbage of adjacent shrubShrub
A shrub or bush is distinguished from a tree by its multiple stems and shorter height, usually under 5–6 m tall. A large number of plants may become either shrubs or trees, depending on the growing conditions they experience...
s. In dry years the plant grows only a few centimeters long before flowering, but after abundant rain it may climb to the tops of neighboring shrubs. The leaves are 2 to 5 centimeters long and are made up of several widely spaced narrow leaflets with hairy upper surfaces.
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 an open array of up to 15 pale purple, dark veined flowers. Each flower is up to one centimeter in length. The flowers are insect-pollinated, with the most common pollinator being the megachilid bee
Megachilidae
The Megachilidae are a cosmopolitan family of solitary bees whose pollen-carrying structure is restricted to the ventral surface of the abdomen...
Anthidium dammersi
Anthidium dammersi
Anthidium dammersi is a species of bee in the family Megachilidae, the leaf-cutter, carder, or mason bees....
. The fruit is a hanging legume pod up to 2.5 centimeters long. It is hairless and dries to a leathery or thick papery texture.