Aquilegia Coerulea

''Aquilegia coerulea'', the Colorado columbine, Rocky Mountain columbine, or blue columbine, is a species of flowering plant in the buttercup family, native to the Rocky Mountains and some of the surrounding states of the western United States. It is the state flower of Colorado. The Latin specific name ''coerulea'' (or ''caerulea'') means "sky blue".

Description

''Aquilegia coerulea'' is a herbaceous plant with flowering stems that may be when fully grown. They are perenial and regrow from a simple or branched caudex that is covered in the bases of old petioles, the stems that support individual leaves. The basal leaves, the ones growing from the base of the plant, are always shorter than the flowering stems, just tall. They are compound leaves that are usually biternate, having nine leaflets in total in groups of three. However, occasionally they may be simple with just three leaflets (trifoliate) or more complex (tripinnate). Each leaflet is quite thin and has three . On their upper sides they are green and , smooth and hairless. They may either be glabrous or , covered in fine, minute hairs, on the undersides. Leaflets most often range in size from , but occasionally may be as long as .

Mature plants grow one to ten flowering stems, though averaging three to four, each with three to four flowers. The flowers furthest out on stems opening first and then opening in sequence downward. The plant flower buds nod, facing somewhat downward. The flowers are large and showy with a diameter of as much as , but more often about . They are so striking that the botanists E. O. Wooton and Paul C. Standley enthusiastically wrote of them in their 1915 ''Flora of New Mexico'', The flowers are atop stems, ones that stand perpendicular to the ground, and have five large, spreading sepals that resemble petals in shades of white to deep-blue or occasionally pink in their wild condition. The sepals range in shape from a flattened circle with somewhat pointed ends with the widest part moved toward the base (-) to like a somewhat egg shaped spear head (-ovate). They range in size from 26 to 51 millimeters long and 8–23 millimeters wide.

The five petals have very long tapered spurs, ranging from 25 to 72 millimeters in length, though usually longer than 34 mm. The blades of the petals are 13–28 mm long by 5–14 mm wide. Petals are most often white to cream in color at the front with the spurs having the same range of colors as the sepals. The flowers are scented and produce more volatile molecules during the day than in the evening.

The center of the flower has a projecting cluster of numerous bright orange-yellow stamens, 50–130 total. The flowers are protandrous, developing pollen before the stigma becomes receptive. The stamens range in length from 13 to 24 mm. They surround three to ten unfused carpels with flowers most frequently having six, but varying even on the same plant. If fertilized each of the carpels may develop into a , a dry pod that splits along one side. Each of the pods is round in cross section and is filled with small, smooth, black seeds. Both the number of pods that develop and the number of seeds in the pods decrease for flowers that bloom later on a plant.

The leaves may be mistaken for that of a meadowrue (''Thalictrum''), but the flowers are entirely different and the species cannot be confused while flowering. Similar columbines in its range include '' Aquilegia scopulorum'', '' Aquilegia jonesii'', and '' Aquilegia micrantha''. ''Aquilegia scopulorum'' has leaves that are covered in natural waxes making them blue-green () rather than green. It is found in Nevada and Utah. ''Aquilegia jonesii'' has much shorter spurs on its flowers, just 8–15 mm and grows to the north in Wyoming, Montana, and Alberta. ''Aquilegia micrantha'' has , very sticky, leaves.

Taxonomy

''Aquilegia coerulea'' is classified in genus ''Aquilegia'' in the family Ranunculaceae. A 2013 study found that it is most closely related to '' Aquilegia elegantula'', '' Aquilegia skinneri'', and '' Aquilegia longissima''.

The first scientific description of ''Aquilegia coerulea'' was by the American scientist Edwin James in 1822. Though ''Aquilegia coerulea'' was the original spelling by James, it has often been spelled as ''Aquilegia caerulea'' as this is more correct Latin. However, the rules of taxonomic nomenclature generally prefer the original spelling and this is the name adopted by the Board of International Botanic Nomenclature. James found the first specimen he collected in a thicket of scrub oak near what is today Palmer Lake, Colorado while on the Stephen H. Long Expedition of 1820. After James's description seven species, six subspecies, five varieties, and two botanical forms have been described that are considered to be synonyms of the species or one of its four varieties.

Varieties

There are four widely accepted varieties of ''Aquilegia coerulea'' according to Plants of the World Online, World Flora Online, and World Plants. Though World Plants additionally lists ''Aquilegia coerulea'' var. ''daileyae'' as valid as does the USDA Natural Resources Conservation Service PLANTS database.

''Aquilegia coerulea'' var. ''alpina''

This variety was scientifically described by the botanist Aven Nelson in 1896. It is known by the common name of Colorado alpine columbine. Though botanical writers such as Robert Nold doubt the validity of the variety. It differs from the other varieties by having much smaller petal blades, only 13–17 millimeters instead of 19–28 millimeters. It grows on open rocky slopes in the state of Wyoming at elevations of . It always has pale blue sepals and flowers from June to August. NatureServe has not evaluated the variety since 2001, but at that time they listed it as vulnerable (T3), but they also list it as possibly extirpated from Wyoming and with an unevaluated status in Utah.

''Aquilegia coerulea'' var. ''coerulea''

Five species were described at various times that are considered heterotypic synonyms of this variety. The autonymic variety of the species grows in Wyoming, New Mexico, and Colorado at elevations of .

It is distinguished from the two following varieties by having medium to deep blue sepals where they have white, pale blue, or pink sepals. Its sepals range in length from 28 to 51 millimeters. The petals have spurs that are 34–48 mm long while their blades are usually 20–24 mm, though occasionally as short as 17 mm. They grow on rocky slopes, near streams, in open woodlands, and in herb dominated meadows. They flower in the summer starting in mid-June and may flower as late as early September. NatureServe evaluated the variety in 2004 and found it to be apparently secure (T4) globally and in Wyoming. They did not evaluate the rest of its range.

''Aquilegia coerulea'' var. ''daileyae''

This disputed variety was described by the botanist Alice Eastwood in 1897. It is a variation where the petals lack spurs and both the petals and spurs are colored deep blue and commonly called spurless columbine, but is also sometimes called Dailey's columbine or star-flowered columbine. The spurless columbine may be found in identical habitats to var. ''coerulea'', but only in the state of Colorado. From the foothills to alpine areas forest openings.

Colorado resident Anna Dailey collected specimens of the spurless columbine near Evergreen, Colorado and sent them to Eastwood. A genetic mutation causes the petals to be replaced with a second set of sepals. The population continues to reproduce in and near the Reynolds Park open space in Jefferson County, Colorado. They are also found around Estes Park, Colorado near Rocky Mountain National Park. Though lacking parts to produce nectar the flowers are still pollinated by bumblebees, which collect pollen from the plants. When NatureServe evaluated it in 1991 as a variety they rated it as imperiled (T2).

''Aquilegia coerulea'' var. ''ochroleuca''

William Jackson Hooker described this variety in 1864. It had previously been described as a species by Thomas Nuttall in 1834 with the name ''Aquilegia leptoceras''. This species name was also unnecessarily reclassified as ''Aquilegia coerulea'' var. ''leptoceras'' by Aven Nelson in 1909. It was inadvertently described by Asa Gray as ''Aquilegia coerulea'' var. ''albiflora'' in 1895 from which it was reclassified by Edwin Blake Payson as a subspecies in 1918. It was not recognized as a distinct variety of the species in ''A Utah Flora'' in 1987 and by Alan T. Whittemore in 1997.

It differs from var. ''coerulea'' by having lighter blue or white sepals (occasionally pink) and from var. ''pinetorum'' by having shorter flower spurs (usually 40–48 mm, but possibly 36–54 mm) and shorter stamens (13–18 mm). It grows in Idaho, Montana, Nevada, Utah, and Wyoming at elevations of . It flowers as early as late June and may bloom as late as August. It is commonly known as white Colorado columbine, despite the fact that it may have light blue or pink sepals. When it was evaluated by NatureServe in 2004, they assigned it the status of apparently secure (T4).

''Aquilegia coerulea'' var. ''pinetorum''

This variety was first described as a species with the name ''Aquilegia pinetorum'' in 1910 by Ivar Tidestrom. In 1918 Edwin Blake Payson described it as subspecies of ''Aquilegia coerulea'' and in 1942 Thomas Henry Kearney and Robert Hibbs Peebles gave it the present classification as ''Aquilegia coerulea'' var. ''pinetorum''.

Like var. ''ochroleuca'' it may have white to pale blue sepals, occasionally light pink, while it has longer petal spurs (usually 50–58 mm, but ranging from 45 to 72 mm) and longer flower stamens (17–24 mm). This variety is found in Utah and Arizona at elevations of . They may flower starting in May or as late as September. The variety is reported to intergrade with '' Aquilegia chrysantha'' (golden columbine) north of the grand canyon with Philip A. Munz observing it is very difficult to distinguish between dried specimens in herbariums. When the variety was evaluated by NatureServe in 2004 they rated it as a vulnerable variety (T3) over the whole of its range and crititcally imperiled in the state of Nevada.

Names

The genus name, ''Aquilegia'', is frequently said to mean "eagle-like". The author Bill Casselman strongly asserts this to be incorrect and that the name derives from the Latin adjective "aquilegus" with the meaning "drawing water". The species name, ''coerulea'', is Botanical Latin meaning "sky-blue" or "dark-blue".

Two of the most frequently used common names in English are ''Colorado columbine'' and ''Colorado blue columbine''. However, the species is also called ''Rocky Mountain columbine'' for its wider natural range, however this name is also infrequently applied to '' Aquilegia saximontana''. The common name ''columbine'' is suggested to be related to the Latin for "Dove" for a resemblance of five doves drinking at a fountain. ''Aquilegia coerulea'' is also known as ''blue columbine'' or simply as ''columbine'', though '' Aquilegia brevistyla'' is occasionally known as blue columbine and many species are casually called columbines such as ''Aquilegia canadensis''.

In the Gosiute dialect of the Shoshoni language ''Aquilegia coerulea'' is called either or as recorded by Ralph Vary Chamberlin.

Range and habitat

Colorado columbine is native to the Rocky Mountains from northern New Mexico to southern Montana. It grows in all of the mountainous western half of Colorado and Wyoming. Additionally it grows in every county of Utah, parts of Nevada, and northern Arizona. It is listed by the USDA as growing in Idaho and South Dakota, but without county level distributions. The species was reported to grow in the Caribou–Targhee National Forest in eastern Idaho in 1973. Though the geographic center of the range is in eastern Utah, the greatest number of plants is found in the mountains of north central Colorado.

Rocky Mountain columbine grows in mountainous areas, starting at lower elevations with the Rocky Mountain variety of the Douglas-fir. They become more common at higher elevations in montane ecosystems and subalpine habitats with some growing above timberline in the alpine tundra. The lowest elevations where they grow naturally is for ''Aquilegia coerulea'' var. ''pinetorum'' and the highest is for ''Aquilegia coerulea'' var. ''coerulea'' in the southern Rocky Mountains. This species of columbine grows poorly in heavy soils without good drainage. However, it prefers moist areas and is very often found in quaking aspen groves. It will also grow in the open coniferous forests, meadows, and in clearings. When there is sufficient water they will thrive on rocky outcrops and slopes.

Ecology

Within its natural range ''Aquilegia coerulea'' is most often pollinated by hawkmoths and bumblebees. Specific species of hawkmoth include ''Hyles lineata'' and '' Sphinx vashti''. The bumblebees include ''Bombus appositus'', but '' Bombus flavifrons'' visit the flowers much more frequently. Hawkmoths visit most often during the night while bumblebees only visit during daylight hours. The plants have the highest rate of cross-fertilization between plants in areas where the number of flowers is smaller and the population of hawkmoths is highest. Normally, only hawkmoths with their very long tongues are able access the nectar at the bottom of the very long spurs with bumblebees visiting primarily or only for pollen.

The western bumblebee (''Bombus occidentalis'') has been observed nectar robbing from ''Aquilegia coerulea'' by opening or using holes cut in the spurs. Though prior to its decline in numbers in the 21st century they were also a significant pollinator of the species in some areas. The broad-tailed hummingbird also visits the blooms, but at a much lower rate than moths or bees.

Conservation

The conservation organization NatureServe reviewed the species in 1991 and found it to be globally secure (G5) due to being a widespread species that is very common in some areas.They also rated it as apparently secure (S4) in both Colorado and Wyoming. However they also rated it vulnerable (S3) in Montana and Nevada and imperiled (S2) in Arizona. They did not evaluate the rest of its range. The wildflower authors Frank and John Craighead attributed a relative decline in the population of the species to overgrazing by sheep and cattle in 1963.

Uses

Culture

Though it is not the standard form for a columbine, the long spurs and shape of the Colorado columbine's flower is the most recognized in the genus. The white and lavender variety of the columbine was officially instituted as the flower symbol of Colorado on 4 April 1899 by an act of the Colorado General Assembly. In 1925 the species was protected by law in Colorado, preventing needless destruction or waste of the flowers. It prohibits the digging or uprooting Colorado columbine plants on public lands and prohibits picking more than twenty-five flowers, buds, or stems in one day. In the 1890s there was also a group called the Columbine Association that sought to establish it as the national flower of the United States. It is used in the logos of the American Society of Plant Taxonomists as well as the Colorado Native Plant Society.

Cultivation

''Aquilegia coerulea'' is used as an ornamental plant in gardens. The species was adopted as a garden plant very soon after its scientific description, with its introduction to the United Kingdom coming in 1864. It is also planted in American gardens for its attractiveness to hummingbirds. They are tolerant of damage by deer and rabbits. It is also recommended as an attractive plant for revegitation of mountain roadsides in its native range by the Office of Natural Environment in the Federal Highway Administration. When planting large areas it is seeded at a rate of 112 ounces per acre.

Colorado columbine is winter hardy in USDA zones 3–8. Plants in cultivation grow most successfully in average to medium garden soil that is well drained and even moisture. They may be grown by gardeners in full sun or partial shade, but plants grow best in light to moderate shade. It is propagated both by seed and the division of plants.

Colorado columbine is vulnerable to powdery mildews, particularly when its leaves are regularly wetted by overhead irrigation. It is also susceptible to infestation by aphids, though not more than other species of columbine. Plants can also be attacked by leaf-miner flies and sawflies.

The treatment of seeds with gibberellic acid and planting at results in 93% germination after three weeks. The seeds also display resistance to sprouting without treatment with none sprouting when planted at 21 °C and 40% germination after two weeks after first being cold stratified at . When grown in gardens plants will last three or four years a most and often are treated by gardeners like a biennial.

Its natural variability and ease of hybridization with other columbines is exploited in the selection of numerous cultivars in different shades. This is a drawback to gardeners seeking to have standard blue and white columbines, often requiring them to seek collected seeds rather than replanting. The cultivars that are probably entirely or largely derived from Rocky Mountain columbine include 'Alba', 'Albiflora', and 'Snow Queen'. Cultivars that are thought to be significantly of ''A. coerulea'' ancestry include 'crimson star' and 'rose queen'. The 'Origami' series of hybrids such as 'Origami Blue', 'Origami White', and 'Origami Yellow' are listed by authors such as P. Allen Smith and Allan Armitage as being largely derived from ''A. coerulea'', but plant sellers will sometimes list them as ''Aquilegia vulgaris''. The 'Origami' hybrids were originally developed by Goldsmith Seeds. The genome of the 'Goldsmith' cultivar was sequenced as part of a study of the transfer of genes between columbine species and was later used to study the evolution of basal eudicots.

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{{Portalbar, Plants, Biology, Arizona, Colorado, New Mexico, Utah

coerulea
Flora of Arizona
Flora of Colorado
Flora of Idaho
Flora of Montana
Flora of Nevada
Flora of New Mexico
Flora of South Dakota
Flora of Utah
Flora of Wyoming
Garden plants of North America
Symbols of Colorado
Taxa named by Edwin James
Plants described in 1822