Biology:Halenia deflexa
| Halenia deflexa | |
|---|---|
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| Halenia deflexa at Isle Royale National Park, Michigan | |
Scientific classification 
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| Kingdom: | Plantae |
| Clade: | Tracheophytes |
| Clade: | Angiosperms |
| Clade: | Eudicots |
| Clade: | Asterids |
| Order: | Gentianales |
| Family: | Gentianaceae |
| Genus: | Halenia |
| Species: | H. deflexa
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| Binomial name | |
| Halenia deflexa (Sm.) Griseb.
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Halenia deflexa, also known as green gentian or spurred gentian[1] is a plant in the gentian family (Gentianaceae). This species grows in wetlands and moist forests across much of the northern United States and Canada. Its common names refer to the prominent spurs on its mostly green flowers. These spurs bear nectar to attract insect pollinators, but the flowers are self-compatible and frequently self-fertilize.
Description
Halenia deflexa plants have one erect stem, 0.2 to 9 dm (0.79 to 35.43 in) tall, typically unbranched but sometimes with a few short branches.[2] The stems of the green gentian are hairless and have square cross-sections.[3] Plants have both basal and cauline leaves. The basal leaves are spatulate or elliptic and are sometimes borne on short petioles, as are the lowermost cauline leaves. The cauline leaves are 1 to 7 cm (1⁄2 to 2 3⁄4 in) long and 5 to 30 mm (1⁄4 to 1 1⁄8 in) wide, and are elliptic near the base, and gradually become narrow and lanceolate toward the end of the stem.[2] The leaves are characteristically toothless, hairless, and glossy.[3]
The flowers, which bloom from July to August, come in groups of between two and nine and are from 1⁄3 to 1⁄2 in (8 to 13 mm) long[1] with four petals. Each has a spur up to a fifth inch long, extending back past the sepals (each of the parts of the calyx of a flower, enclosing the petals). The color of H. deflexa is a shade of purple or a light green. The sepals are green and elliptic (adjoined between the spurs) about half the length of the petals above the spur.
The fruit of the plant is a capsule, conical in shape, which sticks out from the opening of the flower. The fruit is typically dry and once ripe will split open.[3]
Ecology
Although Halenia deflexa flowers are self-compatible, meaning that they can fertilize themselves, they also attract insect pollinators to help with outcrossing.[4] The frequency of insect pollination decreases over the course of the flowering period, and late-season flowers mostly self-pollinate. Bumblebees are the primary pollinator of H. deflexa and are rewarded with nectar, which they access from the flower spurs using their long probosces. In the mornings, after the plants have refreshed the nectar supplies, hoverflies, which have shorter probosces, can also access the nectar and act as less frequent pollinators.[5]
Halenia deflexa is the host for at least two fungal pathogens. The leaf spot fungus Cercospora haleniae causes brown, circular spots with irregular edges on both sides of H. deflexa leaves.[6] It has been reported in Manitoba (its type locality), Wisconsin, and Michigan and only grows on H. deflexa.[7] A rust fungus, Puccinia haleniae, is also a specialist on H. deflexa and creates clusters of small, shiny black raised bumps on the stems and upper leaf surfaces of the host plant.[8]
Geographic distribution
Halenia deflexa grows in moist settings, often in calcareous soils, including in woods, swamps, and along the margins of bodies of water. Its geographic range includes much of Canada, from Atlantic Canada westward to British Columbia and the Northwest Territories, and the northern United states, from New England to Montana and Wyoming. Its elevational range is 0–2000 m.[2]
In eastern Canada, some plants growing in exposed sites with rocky or sandy soils are smaller in stature, with shorter, thicker spurs,[9] more densely-spaced leaves, and darker purple flowers.[2] Asa Gray formally named these plants Halenia deflexa var. brentoniana.[9] Modern authorities do not recognize this variety, interpreting its morphological differences as responses to extreme environments rather than as taxonomically meaningful and noting many plants of intermediate character at less extreme sites in Canada.[2]
Conservation
Globally, Halenia deflexa is considered secure, although the species is rare or threatened in some parts of its range.[10] The species is considered endangered in New York[11] and Vermont,[12] and it may be extirpated in Massachusetts.[3][13] In Wyoming, North Dakota, Labrador, and Nova Scotia, H. deflexa is considered threatened or imperiled.[10]
References
- ↑ 1.0 1.1 Chayka, Katy; Dziuk, Peter (2016), Halenia deflexa (American Spurred Gentian), https://www.minnesotawildflowers.info/flower/american-spurred-gentian, retrieved 2017-09-15
- ↑ 2.0 2.1 2.2 2.3 2.4 "Halenia deflexa in Flora of North America @ efloras.org". http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=250131039.
- ↑ 3.0 3.1 3.2 3.3 "Halenia deflexa", Go Botany (New England Wildflower Society), https://gobotany.nativeplanttrust.org/species/Halenia/deflexa/, retrieved 2017-09-15
- ↑ McConnell, Sara Katelyn (April 22, 2020). Describing the Mating System of Halenia deflexa, a Native New Brunswick Plant (Thesis). Mount Allison University.
- ↑ Kierstead, Roisin (May 6, 2020). How do floral changes affect the pollination ecology of Halenia deflexa (Thesis). Mount Allison University. Retrieved June 1, 2026.
- ↑ Braun, Uwe; Farr, David F.; Minnis, Andrew M. (2009). "Nomenclatural notes on some cercosporoid hyphomycetes". Schlechtendalia (19): 81-84. https://www.researchgate.net/publication/47442524_Nomenclatural_notes_on_some_cercosporoid_hyphomycetes.
- ↑ Chupp, Charles (1953). A Monograph of the Fungus Genus Cercospora. Ithica, NY. pp. 239. https://www.npdn.org/sites/npdnd9b.ceris.purdue.edu/files/basic-page/chupp1953-Cercospora-CAT10620693-bitonal.pdf.
- ↑ Arthur, J.C. (October 1, 1887). A Report on Botanical Work in Minnesota for the Year 1886. St. Paul, Minnesota: Pioneer Press Company. pp. 30.
- ↑ 9.0 9.1 Gray, Asa (1878). Synoptical Flora of North America. Pt. 1. 2. Ivison, Blakeman, Taylor, and company. pp. 127. https://catalog.hathitrust.org/Record/002000806.
- ↑ 10.0 10.1 "NatureServe Explorer 2.0". https://explorer.natureserve.org/Taxon/ELEMENT_GLOBAL.2.143347/Halenia_deflexa.
- ↑ "Spurred Gentian Guide - New York Natural Heritage Program". https://guides.nynhp.org/spurred-gentian/.
- ↑ "Halenia deflexa (American spurred-gentian): Go Botany". https://gobotany.nativeplanttrust.org/species/halenia/deflexa/.
- ↑ "Spurred Gentian" (in en). https://www.mass.gov/info-details/spurred-gentian.
Wikidata ☰ Q15482118 entry
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