Campanula petiolata is a flowering plant that is called western harebell when it is distinguished from Campanula rotundifolia or simply harebell when it is considered the same species. It is in the bellflower family (Campanulaceae). This herbaceous perennial is found in areas of western North America with continental climates. It produces violet-blue, bell-shaped flowers in late summer and autumn. It is closely related to Campanula rotundifolia and is considered either a subspecies or the same species by many botanists.
| Campanula petiolata | |
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Scientific classification 
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| Kingdom: | Plantae |
| Clade: | Tracheophytes |
| Clade: | Angiosperms |
| Clade: | Eudicots |
| Clade: | Asterids |
| Order: | Asterales |
| Family: | Campanulaceae |
| Genus: | Campanula |
| Species: | C. petiolata
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| Binomial name | |
| Campanula petiolata | |
| Synonyms[1] | |
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Description
editCampanula petiolata is a slender, prostrate to erect herbaceous perennial 10–50 centimeters tall when fully developed. The leaves at the base of the plant (basal leaves) are round to egg shaped (ovate) in shape, mostly toothed, and usually disappear before the plants flower.[2] The basal leaves are more often ovate than round.[3]
The leaves on the lower stem are slightly widened in the middle to resembling a skinny lance point (lanceolate) with saw toothed edges (serrate). The upper leaves are reduced to being long and thin like a grass blade (linear) or just slightly lanceolate.[2] Due to the drier habitats of North America the foliage is firmer than that of Campanula rotundifolia.[4] The leaf surfaces are usually smooth, but are rarely slightly rough in texture with fine hairs (scabrous-pubescent).[2]
The flowering stems are usually smooth, but when hairy the very small hairs cover the stem completely rather than being confined to lines on the stem. The stems tend to be more upright (strict) than Campanula rotundifolia.[3] The inflorescence is a panicle or raceme, with 1 to many flowers borne on very slender pedicels.[2][5] The flowers are a bell shape with five points from the five sepals fused together (5-cleft calyx). The flower is sometimes broader than it is long.[2] The flowers are usually a pale lavender to dawn blue in color. Plants with pale white or albino flowers may also occur, the former with a pink-lavender stigma and the later with a creamy white stigma.[4]
When flowering if finished the plant produces a nodding capsule that contains the very minute seeds.[2] It has short underground rhizomes.[6]
Taxonomy
edit
Campanula petiolata was scientifically described and named by Alphonse Pyramus de Candolle in his 1830 publication, Monographie des campanulées.[1][7] It was subsequently described as a subspecies of Campanula rotundifolia as var. petiolata by Joseph Kaye Henry in 1915.[8] Reprints of some authoritative plant identification books, such as Handbook of Northwest Flowering Plants by Gilkey and Powell, continued to list C. petiolata as a separate species as late as 1961.[5]
It is considered an accepted species by Plants of the World Online,[1] World Flora Online,[9] and World Plants.[10] It also is used as a taxon to record observations on iNaturalist.[11] In contrast the USDA Natural Resources Conservation Service PLANTS database lists it as a synonym to Campanula rotundifolia.[12]
Regardless of the validity of Campanula petiolata as a species, modern research indicates the European and North American populations separated due to a colonization event approximately 114 thousand years before the present. North American populations are derived from and most closely related to the Campanula rotundifolia populations of Northern Europe, especially those in Sweden and Ireland.[13]
Names
editCampanula petiolata's binomial name refers to the bell shaped flowers of its genus[14] and to leaves being petiolate, having a short stalk to attach them to the main stem. The wildflower writer Claude A. Barr used the common name western harebell to distinguish this species from the European species.[4] Often a full list of European common or traditional names are also attributed to Campanula petiolata when it is assumed it is the same species as the flower that grow in Europe, such as "bellflower", "lady's thimble", "witch's thimble", "heathbells", "bluebells", "fairies’ thimbles", and "dead men’s bells".[15]
Habitat and range
editPlants of the world online records Campanula petiolata as growing in the far north of Canada in Nunavut and the Yukon southwards to the United States west of the Dakotas, Colorado, and Texas. The southern limit of its range extends into north east of Mexico.[1] In the Pacific Northwest they are unevenly distributed from sea level to approximately 1900 meters in elevation.[5] In the Southern Rocky Mountains they are often found on grassy hillsides, in lodgepole pine forests, along road cuts in montane ecosystems from the foothills to the timberline.[16][17] In northern Mexico it grows in three states, Chihuahua, Coahuila, and Nuevo León.[10] Campanula petiolata will grow in relatively dry areas in the mountains or in medium (mesic) soils, but require well drained gravely or sandy soils if conditions have more moisture.[17]
Ecology
editThe leaf-cutter bee species Megachile melanophaea has been collected from the flowers of Campanula petiolata at least once.[18] It is one of the few plants that will continue to bloom in the high mountain parks of Colorado into the summer from mid July to August.[6]
Cultivation
editThe western harebell is rhizomatous, forming a clump of plants and tends to have more of this character when growing in sunny conditions.[4]
References
edit- ^ a b c d POWO (2023). "Campanula petiolata A.DC". Plants of the World Online. Royal Botanic Gardens, Kew. Retrieved 7 July 2024.
- ^ a b c d e f Henry, Joseph Kaye (1915). Flora of southern British Columbia and Vancouver Island: with many references to Alaska and northern species. Toronto: W.J. Gage & Co. Ltd. p. 283. Retrieved 30 May 2023.
- ^ a b Rydberg, Per Axel (1 January 1903). "A recent Monograph of Campanula rotundifolia and its Allies". Bulletin of the Torrey Botanical Club. 3: 10–11. Retrieved 14 July 2023.
- ^ a b c d Barr, Claude A. (1983). Jewels of the plains : wild flowers of the Great Plains grasslands and hills. Minneapolis: University of Minnesota Press. pp. 52–53. ISBN 0-8166-1127-0.
- ^ a b c Gilkey, Helen M.; Powell, Garland M. (1961). Handbook of Northwest Flowering Plants (2nd ed.). Portland, Oregon: Binford and Mort, Publishers. Retrieved 8 June 2023.
- ^ a b Ramaley, Francis (September 1916). "Dry Grassland of a High Mountain in Northern Colorado". Plant World; A Monthly Journal of General Botany. 19 (9). Binghamton: 254, 267. Retrieved 14 July 2023.
- ^ Candolle, Alphonse Pyramus de (1830). Monographie des campanulées. Paris: Veuve Desray. pp. 278–281. Retrieved 16 May 2023.
- ^ POWO (2023). "Campanula rotundifolia var. petiolata (A.DC.) J.K.Henry". Plants of the World Online. Royal Botanic Gardens, Kew. Retrieved 16 May 2023.
- ^ "Campanula petiolata A.DC". World Flora Online. Retrieved 7 July 2024.
- ^ a b Hassler, Michael (30 June 2024). "Synonymic Checklist and Distribution of the World Flora. Version 19.4". World Plants. Retrieved 7 July 2024.
- ^ "western harebell (Campanula petiolata)". iNaturalist. Retrieved 7 July 2024.
- ^ NRCS (7 July 2024), "Plants Database", United States Department of Agriculture (USDA)
- ^ Sutherland, Brittany L.; Galloway, Laura F. (October 2018). "Effects of glaciation and whole genome duplication on the distribution of the Campanula rotundifolia polyploid complex". American Journal of Botany. 105 (10): 1760–1770. doi:10.1002/ajb2.1162. PMID 30312483.
- ^ "Campanula rotundifolia". Jepson Herbarium. University of California, Berkeley. Retrieved 14 July 2023.
- ^ Ruta McGhan, Patricia J. "Harebell". Celebrating Wildflowers - Plant of the Week. U.S. Forest Service. Retrieved 12 May 2023.
- ^ Rydberg, Per Axel (December 1921). "Phytogeographical notes on the Rocky Mountain region X. Grasslands and other open formation of the Montane Zone of the Southern Rockies". The Bulletin of the Torrey Botanical Club. 48 (12). Torrey Botanical Society: 323–325. doi:10.2307/2480008. JSTOR 2480008.
- ^ a b Reed, E. L. (1 February 1917). "Meadow Vegetation in the Montane Region of Northern Colorado". Bulletin of the Torrey Botanical Club. 44: 99, 100, 102, 105–108. doi:10.2307/2479536. JSTOR 2479536. Retrieved 14 July 2023.
- ^ Cockerell, T.D.A. (December 1910). "Some Bees from Eldora, Colorado". Psyche: A Journal of Entomology. 17 (6). Cambridge Entomological Club: 246. doi:10.1155/1910/71484.