Geum Triflorum

''Geum triflorum'', commonly known as prairie smoke, torch flower, long-plumed purple avens, lion's beard, three-flowered avens, or old man's whiskers, is a spring-blooming perennial herbaceous plant belonging to the ''Geum'' genus. It is a hemiboreal/continental climate species that is widespread in colder and drier environments of western North America, although it does occur in isolated populations as far east as New York and Ontario. It is particularly known for the long feathery plumes on the seed heads that have inspired many of the regional common names and aid in wind dispersal of its seeds.

Morphology

''Geum triflorum'' is a perennial herb which forms colonies of stemless rosettes by short, spreading roots called rhizomes which have a sassafras-like flavor. The leaves grow from a caudex and are 4-30 cm long. They are divided into leaflets with deep divisions that makes the leaves resemble the leaves of a fern. The leaflets are arranged pinnately along a common leaf stem with smaller leaflets mixed in with 7-18 larger ones and single larger leaflet at the end of the leaf. The leaves are covered with extremely small downy hairs.

Early in the spring the leaves often lay flat to the ground and are in poor condition, but soon become more upright in response to the warmer days and lack of snow cover. In the heat of a dry summer the leaves will also lay down closer to the earth. The plants resume growth in the fall as other plants are starting to go dormant, growing an impressive mound of deep grey-green leaves. The leaves are evergreen in areas without severe cold or there is protective snow cover, though they often turn purple, orange, or reddish.

The flowers of ''G. triflorum'' appear from mid-spring to early summer. The flowering stalks stand well above the leaves on red-purple-maroon stems 10-45 cm in height. The flowering stem is almost bare with a few very small leaves called bractlets on the main stem and where the arching flower stalks (pedicels) attach to the main stem. Each flower hangs upside down by itself from a separate pedicle. There are usually three flowers on each flower stalk, but sometimes one, five, or even seven per stalk. The sepals are strongly closed and pink to maroon in color, covered in fine downy hairs, with five narrow pointed bracts radiating outward toward the base of the flower. The flowers contain five 7-13 mm long elliptical petals mostly to entirely hidden under the sepals. They are most often a light yellow to cream in color, but sometimes have a blush of pink or purple and purple veins.

When pollination is completed the flower heads turn upright and the sepals begin to open. The petals may be visible at this stage. The many styles grow longer, eventually becoming 15-70 mm in length. The styles are densely covered in fine hairs making them resemble downy bird feathers or wisps of mauve smoke. The seed heads start out pale pink in color and fade to tan or grey as the seeds mature in mid-summer. The seeds do not appear to need cold stratification as germination did not change significantly when tested.

Taxonomy

''Geum triflorum'' was named and described by Frederick Traugott Pursh in his book ''Flora americae septentrionalis'' using a 1811 collection by John Bradbury. He placed the species within Linnaeus' ''Geum'', a genus with a name derived from Greek for "taste", with the species name of ''G. triflorum'' for the three flowers usually present on each flower stalk. The species was previously collected in Idaho on 12 June 1806 by Meriwether Lewis, but was not described by him and that specimen was incorrectly described as a new species named ''Geum ciliatum'' by Pursh. Kurt Sprengel placed it in ''Sieversia'' as ''S. triflora'' in his update of Systema Vegetabilium published in 1825. This classification was eventually rejected as was the 1906 attempt by Edward Lee Greene to create a new genus that would reclassify G. triflorum as ''Erythrocoma triflora'' and separate out a dozen regional varieties as separate species.

Subspecies

G. triflorum has three subspecies that are accepted by many, but not all, authorities, as of 2023.

* ''Geum triflorum'' var. ''campanulatum'' (Greene) C.L.Hitchc.
* ''Geum triflorum'' var. ''canescens'' (Greene) Kartesz & Gandhi
* ''Geum triflorum'' var. ''ciliatum'' (Pursh) Fassett

''Geum triflorum'' var. ''campanalatum'' was described as a separate species, ''Erythrocoma campanulata'', by Greene and as ''Geum campanulatum'' by G.N. Jones, but Charles Leo Hitchcock argued for its classification as a subspecies of G. triflorum in 1961, writing, "There has been much diversity of opinion regarding both the generic status of, and significance of the variation in, this complex. In general the several taxa that have been recognized at the specific level are largely sympatric and completely transitional and there seems to be no good reason to recognize more than 3 races for our area..." This has become the accepted view as researched by Richard Pankhurst. It differs in having leaflets that are rounder (obovate-cuneiform instead of cuneiform), shorter leaves overall, and flowers that are more open/bell shaped (campanulate). It was described from a type specimen found in the Olympic Mountains. It is recorded by the USDA as growing in Washington state and Oregon. This subspecies is accepted by World Flora Online and the USDA, but not Kew Gardens or Flora of North America.

''Geum triflorum'' var. ''canescens'' was similarly described by Greene as ''Erythrocoma canescens'' in his 1906 book. Arguing against ''Erythrocoma'', the Swedish-American botanist Per Axel Rydberg classified it as ''Sieversia canescens'' in 1913. In 1958 Philip A. Munz accepted it as a species, but moved it back to ''Geum'' as ''Geum canescens''. In 1990 John T. Kartesz and Kanchi Gandhi published an article on the nomenclature of North American plants giving it its current status as a subspecies of ''G. triflorum''. The type specimen was collected in the northern Sierra Nevada Mountains in 1863 near Ebbett's Pass. It is distinguished by being stouter and sometimes taller than ''Geum triflorum'' var. ''campanalatum'' and covered in grayish-white hairs on the leaves "canescently soft-villous and sparsely pilose", but with similarly shorter leaves than the species. It is recorded by the USDA as growing in Pacific Northwest of the United States including California, Idaho, Montana, Nevada, Oregon, Washington state, and Wyoming with county level distribution records in northern California and Nevada. This subspecies is accepted by World Flora Online and the USDA, but not Kew Gardens or Flora of North America.

''Geum triflorum'' var. ''ciliatum'' was first described as a species, ''Geum ciliatum'', by Pursh at the same time as he described ''G. triflorum''. George Don reclassified it as ''Sieversia ciliata'' in 1832 in the book ''A General History of the Dichlamydeous Plants''. It was similarly placed by Greene into his proposed Erythrocoma, but he separated it into two species, ''Erythrocoma ciliata'' and ''Erythrocoma grisea''. In 1913 Rydberg described ''Sieversia grisea'', but this is now accepted as a synonym for the subspecies. While there were other published classifications, the one currently accepted was written by Norman Carter Fassett and published in 1928 in the journal Rhodora. The subspecies is distinguished by having larger leaflets that are cleft (having a deep division) for more than half their lengths and the seed heads having shorter styles, 15-40 mm instead of 15-70 mm. The USDA records it as growing from British Columbia to northern California and from the mountains of New Mexico to Saskatchewan. It is recorded by them as growing in both Colorado and Montana without county level distributions. This subspecies is accepted by World Flora Online, the USDA, Kew Gardens, and Flora of North America.

''Geum triflorum'' var. ''ornatum'' is a subspecies published by Fassett at the same time as ''G. triflorum'' var. ''ciliatum'' in Rhodora. It is not currently accepted by most authorities, including World Flora Online, the USDA, Kew Gardens, and Flora of North America.

Habitat

''G. triflorum'' grows in open, non-forested habitat with well drained soils. This includes meadows in montane forests, prairies of the upper Midwest, and alvars in Michigan, New York, Ontario, and Manatoba. Plants are tolerant of clay soils when slopes provide drainage, but intolerant of being waterlogged, particularly in winter. They require good moisture for new plants to establish and prefer areas that are well supplied with water in the spring, but tolerant of drought in summer and healthier with drier soils in summer. In habitats with more precipitation they will often be found in areas with more freely draining soils and/or on areas raised up above the surrounding landscape. In drier habitats plants will often be found in lower areas that have additional moisture from spring runoff. Prairie smoke plants are tolerant of some shade and prefer some afternoon shade in climates with hot summers.

In the central Rocky Mountains ''G. triflorum'' will grow to around timberline at 3,800 meters and as low as 2,000 meters in the foothills. In New York it grows at an altitude of 90 meters in the
In the midwest it grows near to the level of the great lakes at 90 meters in elevation in Chaumont Barrens Preserve.

Distribution

''G. triflorum'' is widely distributed in North America, but is only common in in the Upper Midwest and mountainous west.

In Canada it is common from British Columbia to Manatoba. It also grows in parts of the Yukon Territory and Northwest Territory. It is a common prairie species in Minnesota, Wisconsin, and North Dakota. Contiguous with this it is reported in nine of the north-eastern counties in Illinois and eight counties in north-eastern South Dakota. It is recorded by the USDA as growing in Iowa without a specific location. It is common throughout the prairies of Montana and Wyoming and into the mountains of Idaho, Colorado, Utah, and Nevada. It is present in the adjoining Black Hills in South Dakota, the eastern portions of Washington state, Oregon, and the north east mountainous portion of California. Populations are also found in the mountains of northern New Mexico and Arizona.

In the eastern United States and Ontario populations are much rarer and isolated. It grows in six counties of the lower peninsula of Michigan and just Chippewa County in the upper peninsula. In New York state is is only recorded by the USDA as growing in Jefferson County and Oswego County, which are adjacent to Lake Ontario. The New York Flora Atlas only records vouchered specimens from Jefferson County, NY.

Ecology

The flowers produce both nectar and pollen. They are visited mainly by bumblebees, which are able to force their way into the mostly closed flowers and reach the nectar. They also buzz-pollinate to dislodge pollen from the stamens and gather it to feed their young. As it blooms early in the season and in large amounts in suitable habitats it is suggested that it is one of the plants that is critical to the success of queen bumblebees in establishing their first brood. Smaller bees such as sweat bees from the genus ''Lasioglossum'' feed on pollen grains from the opening of the flower. Bumblebees are the only effective cross-pollinators. Various insects become nectar robbers by chewing holes in the top of the flower, near the stem, to reach the nectar.

It is not a major source of forage for most native herbivores including mule deer, elk, pronghorn, and game birds, but is foraged by white tailed deer. It is similarly not generally eaten by cattle, horses, or domestic sheep and has a low amount of protein.

Uses

Prairie smoke is planted in gardens as an ornamental plant for its interesting seed heads and for the persistent foliage in the winter. It is popular for native gardens, rock gardens, and with gardeners that wish to have an informal natural look. Plants are winter hardy in USDA zones 3-7 and do not have any serious disease or pest problems. It is planted in either the spring or fall from cultivated plants or by seed. The size of the plant is very dependent on the richness of the soil with very lean soils without organic matter the plants will be quite compact and in rich soils they will become much larger and competitive. It is not tolerant of deep shade and can be crowded out by taller plants which grow over it and deprive it of light.

Some Indigenous peoples of the Northwest Plateau used three-flowered avens to treat tuberculosis. Some Native Americans once made a tea from the plant's roots.

Gallery

Image:Prairie Smoke (8206390634).jpg, USFWS Mountain-Prairie
Image:Geum triflorum - Flickr - aspidoscelis (2).jpg, Flower detail
Image:Geum triflorum var. campanulatum on Olympic National Forest Mount Townsend Trail (4837197389).jpg, Prairie smoke (Geum triflorum) on Olympic National Forest Mount Townsend Trail
Image:Geum triflorum Saskatchewan.jpg, Geum triflorum Saskatchewan, flower side view
Image:Prairie Smoke - Geum triflorum (bac24c04-5d1b-4bbd-a657-f44ec1ef8682).jpg, Geum triflorum in meadow habitat Yellowstone National Park. 11 June 2017
Image:Prairie Smoke (Geum triflorum) Closeup (12758484034).jpg, Detail of the styles on a seed head
Image:Geum triflorum (5088031442).jpg, Immature seed head opened to show the achenes sitting in the persistant hypanthium and bearing plumose tails (modified styles).
Image:Geum triflorum var. triflorum fruiting heads (3478828678).jpg, Meadow habitat mid-summer development of seed heads Olympic National Park.

References

External links

Fire Effects Information SystemWisconsin Horticulture Division of ExtensionJepson Manual TreatmentUSDA Plants Profile

{{Taxonbar, from=Q2709956

triflorum
Flora of Western Canada
Flora of the Northwest Territories
Flora of Ontario
Flora of Yukon
Flora of the Northwestern United States
Flora of the Southwestern United States
Flora of Illinois
Flora of Iowa
Flora of Michigan
Flora of Minnesota
Flora of New Mexico
Flora of New York (state)
Flora of North Dakota
Flora of South Dakota
Flora of Wisconsin
Plants described in 1814
Taxa named by Frederick Traugott Pursh