Polemonium, commonly called Jacob's ladders or Jacob's-ladders, is a genus of between 25 and 40 species of flowering plants in the family Polemoniaceae, native to cool temperate to arctic regions of the Northern Hemisphere. One species also occurs in the southern Andes in South America. Many of the species grow at high altitudes, in mountainous areas. Most of the uncertainty in the number of species relates to those in Eurasia, many of which have been synonymized with Polemonium caeruleum.
Polemonium californicum is a species of flowering plant in the phlox family known by the common names moving polemonium, low Jacob's-ladder, and California Jacob's ladder. It is native to the northwestern United States, where it grows in shady and moist habitat, such as mountain woodlands. It is a hairy, glandular rhizomatous perennial herb forming clumps of several decumbent to erect stems 30 to 50 centimeters in maximum height. The leaves are up to 20 centimeters long and are compound, made up of several pairs of oval to lance-shaped leaflets. The leaflet at the tip of the leaf is often fused to the pair behind it. The inflorescence is a crowded cluster of bell-shaped flowers each up to 1.5 centimeters wide. The flower is blue or purple with a yellow center and a whitish tubular throat. The fruit is a capsule.
Polemonium micranthum is a species of flowering plant in the phlox family known by the common names annual polemonium or annual Jacob's-ladder. It is native to western North America from British Columbia to North Dakota to California as well as disjunct in the Andes of southern Argentina and Chile. It can be found in many types of shrubby habitat, such as sagebrush scrub and foothill woodlands. It is an annual herb with a branching or unbranched stem taking a matted, spreading, or upright form. The slender stems are up to about 30 centimeters long and the herbage is coated in short, soft hairs and stalked glands. The leaves are located along the stem, each divided into several small leaflets. The solitary flowers have small white or pale blue lobed corollas tucked within cuplike calyces of hairy, pointed sepals.
Polemonium occidentale is a species of flowering plant in the phlox family known by the common names western polemonium and western Jacob's-ladder. There are two subspecies. The common ssp. occidentale is native to western North America from British Columbia to Colorado to California, where it can be found in moist areas of many habitat types, including meadows and woodlands. There is also a rare subspecies, ssp. lacustre, which is known only from a total of three counties in Minnesota and Wisconsin, and is found only in white cedar swamp habitat there.
Polemonium pulcherrimum is a species of flowering plant in the phlox family known by several common names, including beautiful Jacob's-ladder, showy Jacob's-ladder, and skunk-leaved polemonium. It is native to western North America from Alaska and Yukon to Arizona and New Mexico, where it can be found in many types of mountain habitat, including alpine talus and rock cracks at high elevations. It is a common and widespread wildflower in several regions. It is a perennial herb producing a clump of several erect stem approaching a maximum height of 30 centimeters. The leaves are mostly basal, with smaller ones arranged along the stem. The leaves are made up of several pairs of lance-shaped to oval or round leaflets. The herbage is lightly hairy, densely glandular, sticky, and strongly scented, the odor reminiscent of skunk. The showy inflorescence is a dense elongated or headlike cluster of bell-shaped flowers each just under a centimeter wide. The flower is deep to bright or pale blue to nearly white with a yellow throat.
Polygala lewtonii is a rare species of flowering plant in the milkwort family known by the common name Lewton's polygala, or Lewton's milkwort. It is endemic to Florida in the United States, where it is limited to the central ridge of the peninsula. There are about 49 occurrences of the plant remaining. Most occurrences contain very few plants. The species is threatened by the loss and degradation of its habitat. This is a federally listed endangered species of the United States.
Polygonum basiramia is a rare species of flowering plant in the knotweed family known by the common names wireweed, hairy wireweed, purple wireweed, and Florida jointweed. It is endemic to Florida in the United States, where it is limited to the central ridges of the peninsula, including the Lake Wales Ridge. It is threatened by the loss and degradation of its habitat. It is a federally listed endangered species of the United States.
Scutellaria floridana, the Florida skullcap, is a rare species of flowering plant. It is endemic to Florida in the United States, where it is known only from the Florida Panhandle. It is threatened by a number of human activities and its small population sizes make it vulnerable. It is a federally listed threatened species.
Silene spaldingii is a rare species of flowering plant in the family Caryophyllaceae known by the common names Spalding's silene, Spalding's catchfly and Spalding's campion. It is native to eastern Washington, eastern Oregon, northern Idaho and northern Montana, where its distribution extends just into British Columbia, Canada. Much of its former habitat has been converted to agriculture and its range is now limited to the last remaining stretches of pristine prairie grassland in this region. It is threatened by the degradation and loss of its remaining habitat. It is federally listed as a threatened species in the United States and it is designated endangered by Canada's COSEWIC.
Cymopterus goodrichii is a rare species of flowering plant in the carrot family known by the common name Toiyabe springparsley. It is endemic to Nevada in the United States, where it occurs in the Toiyabe and West Humboldt Ranges.
Packera castoreus is a rare species of flowering plant in the aster family known by the common names Beaver Mountain groundsel and Beaver Mountain ragwort. It is endemic to Utah in the United States, where it occurs only in the Tushar Mountains.
Astragalus sinuatus is a species of flowering plant in the legume family known by the common name Whited's milkvetch. It is endemic to Washington in the United States, where it is limited to one creek drainage on the western edge of the Columbia Basin. Its range measures about ten square miles in Chelan and Kittitas Counties in the central part of the state.
Calochortus coxii is a rare species of flowering plant in the lily family known by the common names Cox's mariposa lily and crinite mariposa lily. It is endemic to Oregon in the United States, where it is known only from Douglas County.
Cuphea aspera is a species of flowering plant in the loosestrife family known by the common names tropical waxweed and Chapman's waxweed. It is endemic to Florida in the United States, where it is limited to Gulf and Franklin Counties on the central Florida Panhandle. It has likely been extirpated from Calhoun County.
Euphorbia purpurea is a species of Euphorbia known by the common names Darlington's glade spurge, glade spurge, and purple spurge. It is native to the Eastern United States, where it occurs from Ohio and Pennsylvania south to North Carolina. It has been extirpated from Alabama; it was believed lost from Delaware until a population was rediscovered in 1997.
Polemonium vanbruntiae is a species of flowering plant in the phlox family Polemoniaceae. It is known by the common names Appalachian Jacob's ladder, bog Jacob's-ladder, and Vanbrunt's polemonium. It is native to eastern Canada and the northeastern United States.
Silene seelyi is a species of flowering plant in the family Caryophyllaceae known by the common names Seely's catchfly and Seely's silene. It is endemic to Washington state in the United States, where it is limited to the Wenatchee Mountains of Chelan and Kittitas Counties.
Sisyrinchium sarmentosum is a species of flowering plant in the iris family known by the common names mountain blue-eyed grass and pale blue-eyed-grass. It is native to the Pacific Northwest of North America, where it is known from a part of the Cascade Mountains in Washington and Oregon.
Aquilegia laramiensis is a species of flowering plant in the buttercup family known by the common name Laramie columbine. It is endemic to Wyoming in the United States, where it is known only from the Laramie Mountains.
Astragalus leptaleus is a species of flowering plant in the legume family known by the common name park milkvetch. It is native to the Rocky Mountains of the United States, where it occurs in Idaho, Montana, Wyoming, and Colorado.
