Dahlia

Aquilegia coerulea, the Colorado columbine, Rocky Mountain columbline, or blue columbine is a species of flowering plant in the buttercup family Ranunculaceae, 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 15–80 centimeters (6–31 in) when fully grown.^[3] Its leaves are on stems that are always shorter than the flowering stems, just 9–37 cm (4–15 in) and are compound leaves that usually have three leaflets on three components (biternate), but occasionally may be simpler with just three leaflets (trifoliate) or more complex (tripinnate).^[4] Each leaflet is quite thin, smooth and hairless on the upper side (glabrous), and green. They may either be glabrous or covered in fine, minute hairs on the underside of the leaf (pubescent) and have three lobes.^[5][6] Leaflets most often range in size from 13–42 mm (1⁄2–1+5⁄8 in), but occasionally may be as long as 61 mm (2+3⁄8 in).^[4]

The plant flower buds nod, facing somewhat downward.^[7] The flowers are large and showy with a diameter of as much as 15 centimeters (6 in),^[5] but more often about 5–10 cm (2–4 in).^[8] 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,^[5]

"This is the State flower of Colorado and no other State has one so beautiful. Few indeed are the flowers of the Rockies that can compare with this in beauty. The great blossoms, sometimes six inches in diameter, look like bits of fallen sky, and when the plants cover acres of meadow, as they sometimes do, no words can be found to do them justice."^[9]

The flowers are atop stems that stand perpendicular to the ground (erect) with the outer five sepals in shades of white to deep-blue or occasionally pink in their wild condition.^[3] The sepals range in shape from a flattened circle with somewhat pointed ends with the widest part moved toward the base (elliptic-ovate) to like a somewhat egg shaped spear head (lance-ovate}. They range in size from 26–51 millimeters long and 8–23 millimeters wide.^[4]

The five petals have very long tapered spurs,^[10] ranging from 25–72 millimeters in length, though usually longer than 34 mm.^[4][3] The blades of the petals are white to creamy in color and 13–28 mm long by 5–14 mm wide.^[11][4]

The center of the flower has a projecting cluster of numerous bright orange-yellow stamens together with five relatively long pistils.^[10] The stamens range in length from 13 to 24 mm.^[4]

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.^[11]

Taxonomy

The first scientific description of Aquilegia coerulea was by the American scientist Edwin James in 1822.^[2] 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.^[12] 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.^{[2][13][14][15][16]}

Sequencing of the genome of this species has advanced the study of the evolution of basal eudicots.^[17][18]

Varieties

There are four widely accepted varieties of Aquilegia coerulea according to Plants of the World Online,^[2] World Flora Online,^[19] and World Plants.^[20] Though World Plants additionally lists Aquilegia coerulea var. daileyae Eastw. as valid as does the USDA Natural Resources Conservation Service PLANTS database.^[20][21]

Aquilegia coerulea var. alpina

This variety was scientifically described by the botanist Aven Nelson in 1896.^[13] It is known by the common name of Colorado alpine columbine.^[22] Though botanical writers such as Robert Nold doubt the validity of the variety.^[5] It differs from the other varieties by having much smaller petal blades, only 13–17 millimeters instead of 19–28 millimeters.^[4] It grows on open rocky slopes in the state of Wyoming at elevations of 2,100–3,500 meters (6,900–11,500 ft). It always has pale blue sepals and flowers from June to August.^[23] 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.^[22]

Aquilegia coerulea var. coerulea

Five species were described at various times that are considered heterotypic synonyms of this variety.^[14] The autonymic variety of the species grows in Wyoming, New Mexico, and Colorado at elevations of 2,100–3,500 meters (6,900–11,500 ft).^[24] It is distinguished from the two following varieties by having medium to deep blue sepals where they have white, pale blue, or pink sepals.^[4] It's sepals range in length from 28–43 millimeters.^[3] 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.^[24] 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.^[25]

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.^[15] 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).^[4] It grows in Idaho, Montana, Nevada, Utah, and Wyoming at elevations of 2,000–3,600 meters (6,600–11,800 ft). It flowers as early as late June and may bloom as late as August.^[26]

Aquilegia coerulea var. pinetorum

This variety was first described as a species with the name Aquilegia pinetorum in 1910 by Ivar (Frederick) Tidestrøm (1864-1956). 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.^[16] 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 45–72 mm) and longer flower stamens (17–24 mm).^[4] This variety is found in Utah and Arizona at elevations of 1,800–3,400 meters (5,900–11,200 ft). They may flower starting in May or as late as September.^[27]

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".^[28] Other writers speculate that it may derive from "Dove" for a resemblance of five doves drinking at a fountain.^[12] The species name, coerulea, is also Latin meaning "sky-blue" or "dark-blue".^[28]

Two of the most frequently used common names in English are "Colorado columbine" and "Colorado blue columbine".^[6][12] However, the species is also called "Rocky Mountain columbine" for its wider natural range.^[29]

Range

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.^[30]

Uses

The white and lavender variety of the columbine was 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.^[31]

Cultivation

Aquilegia coerulea is used as an ornamental plant in gardens.^[29] The species was adoped as a garden plant very soon after its scientific description, with its introduction to the United Kingdom coming in 1864.^[12] It is also planted in American gardens for its attractiveness to hummingbirds.^[29] They are tollerant of damage by deer and rabbits.^[32] 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.^[33]

Colorado columbine is winter hardy in USDA zones 3–8.^[29] 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.^[32] It is propagated both by seed and the division of plants.^[29]

Colorado columbine is vulnerable powdery mildews, particularly when its leaves are reguarly wetted by overhead irrigation.^[29] It is also susceptable to infestation by aphids,^[34] though not more than other species of columbine.^[5] Plants can also be attacked by leaf-mining flies and sawflies.^[34]

Its natural variability and ease of hybridization with other columbines is exploited in the selection of numerous cultivars in different shades. 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 significatly of A. coerulea ancestry include 'crimson star' and 'rose queen'.^[5] While the 'origami mix' hybirds, origionally developed by Goldsmith Seeds,^[35] are listed by some sources as being derived from A. coerulea others list it as being from Aquilegia vulgaris.^[36][37]

Reflist

External links

• Photos of "Aquilegia coerulea". SW Colorado Wildflowers.
• Colorado state flower
• Aquilegia coerulea Genome sequencing
• "Aquilegia coerulea". Plants for a Future.