Fraxinus profunda
Fraxinus profunda, the pumpkin ash, is a species of Fraxinus (ash) native to eastern North America, primarily in the United States, with a scattered distribution on the Atlantic coastal plain and interior lowland river valleys from southern Maryland northwest to Indiana, southeast to northern Florida, and southwest to southeastern Missouri to Louisiana, and also locally in the extreme south of Canada in Essex County, Ontario.[2][3][4][5] The pumpkin ash tree is native to swampland areas. It is a tree that is very important environmentally and economically. Currently, Fraxinus profunda is threatened by the emerald ash borer which is threatening all species of ash trees in North America. The fruits of the pumpkin ash tree are also the largest of all ash trees in eastern North America.
| Fraxinus profunda | |
|---|---|
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| Pumpkin ash in the Royal Botanic Garden Edinburgh | |
Scientific classification  | |
| Kingdom: | Plantae |
| Clade: | Tracheophytes |
| Clade: | Angiosperms |
| Clade: | Eudicots |
| Clade: | Asterids |
| Order: | Lamiales |
| Family: | Oleaceae |
| Genus: | Fraxinus |
| Section: | Fraxinus sect. Melioides |
| Species: | F. profunda |
| Binomial name | |
| Fraxinus profunda (Bush) Bush | |
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| Natural range of Fraxinus profunda | |
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| Close-up of natural range of Fraxinus profunda | |
| Synonyms | |
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Fraxinus tomentosa F.Michx. | |
Taxonomy
The pumpkin ash tree is a member of the Oleaceae family, and has two synonyms Fraxinus michauxii Britton and Fraxinus tomentosa Michx. f.[6] Benjamin Franklin Bush described the pumpkin ash in 1901.[7] The pumpkin ash tree was erroneously hypothesized to be a fertile cross between Fraxinus pennsylvanica and Fraxinus americana.[8] This tree is also considered to be a hexaploid and has 138 chromosomes.[8] Pumpkin ash was thought to be a cross between Fraxinus pennsylvanica and Fraxinus americana because it shared similarities like abaxial leaf surfaces and how the bark develops as it becomes older.[8] Despite the similarities, it was determined that Fraxinus profunda is a phylogenetically distinct species.[8]
The term pumpkin ash comes from the swollen trunk that can be found at the base of the tree. The other common names of Fraxinus profunda are red ash or swell-butt ash.[9]
Morphology
While normally a medium-sized deciduous tree reaching 12–30 m tall with a trunk up to 1 m diameter, the tree can reach 50 m tall with a 4.7 m diameter trunk.[10] The bark is gray, thick and fissured with a diamond pattern on mature trees. The winter buds are dark brown to blackish, with a velvety texture. The leaves are opposite, pinnate, with 7–9 leaflets; each leaf is 25–40 cm long, the leaflets 8–20 cm long and 5–8 cm broad, with a finely toothed margin; they are downy on the underside and along the rachis. The leaflets are stalked, with a short petiolule. Pumpkin ash trees are angiosperms meaning that they have flowers and fruits rather than seeds.[4] The flowers are produced in panicles in spring shortly before the new leaves; they are inconspicuous purplish-green with no petals, and are wind-pollinated. The fruit is a samara; it is the largest of any North American ash species, 5–8 cm long, comprising a single seed with an elongated apical wing 9 mm broad.[4][5][11][9] Fraxinus profunda leaves have a very similar abaxial side as Fraxinus americana.[8] As the pumpkin ash tree grows and becomes older, the bark starts to become solid ridges that are continuous like the white ash.[8]
Ecology
This tree occurs primarily in swamps. Pumpkin ash is a food plant for the larvae of several species of Lepidoptera; see List of Lepidoptera that feed on ashes. It is also seriously threatened by the invasive Asian emerald ash borer.[11] In 2017, the IUCN assessed the pumpkin ash as Critically Endangered, due to a massive population decline over most of its range due to the emerald ash borer. The emerald ash borer was first discovered in Michigan in 2002.[12] The emerald ash borer attacks the phloem of the pumpkin ash tree.[12] Within a six year period, the EAB can spread quickly and move through local ash tree populations.[12] The pumpkin ash tree is valuable economically and ecologically.[12] Pumpkin ash trees are also susceptible to fire.[4]
Reproduction
Fruit production can begin as early as ten years of age.[4] The seeds grow during the summer and are dropped in the early fall.[4] As the seeds fall the most common type of dispersal is through wind, but with pumpkin ash trees growing it wet areas, the seeds can also be dispersed through the water and can survive wet conditions for months.[4]
As a seedling, it thrives in moist soils in openings in the canopy cover.[4] Dense cover does not benefit the young trees and it will grow very quickly in areas that are open with bare ground.[4] Given highlight and moist conditions, the seedling will grow very quickly and can often outgrow other tree species.[4]
Distribution
Fraxinus profunda is a wetland and swamp tree. These wetland and swamp areas include land types such as tidal estuary swamps, depressions in coastal plains, floodplain flats, and coastal marshes.[4] The range of the pumpkin ash tree tends to be discontinuous.[8] Its native range is in the swamps and river bottoms as far south as northern Florida, and along the east coast up to southern Virginia.[4] Few pumpkin ash trees can be found in southern parts of Illinois and Indiana, northern parts of Arkansas, and southern parts of Missouri.[4]
Climate
Areas where pumpkin ash trees are found typically have an average rainfall of 40 inches to 48 inches of rain per year.[4] During the growing season, from March to September, the average rainfall is around 26 inches. The temperature in areas with this tree average around 80 degrees F in northern states, and 82 degrees F in the southern states. In the winter season, the average temperatures range from 35 degrees F in northern states and 60 degrees F in southern states.[4] The pumpkin ash can tolerate temperatures as low as -24 degrees F.[6]
Uses
Pumpkin ash trees provide resources for humans and animals such as deer and birds. Birds, like wood ducks, feed on the fruit of a Fraxinus profunda.[4] Deer feed on the twigs and leaves of the pumpkin ash tree, and the humans use the woody parts of the tree as lumber for building.[4] In addition to being used as lumber, the wood of pumpkin ash trees can also be used in tools such as stocks or handles.[12] The wood can also be used as lumber, naval store products, and nursery stock products.[6]
References
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Wikimedia Commons has media related to Fraxinus profunda. |
- Jerome, D.; Westwood, M.; Oldfield, S. & Romero-Severson (2016). "Fraxinus profunda". IUCN Red List of Threatened Species. 2016. Retrieved 14 September 2017.CS1 maint: ref=harv (link)
- "Fraxinus profunda". Germplasm Resources Information Network (GRIN). Agricultural Research Service (ARS), United States Department of Agriculture (USDA). Retrieved 14 January 2018.
- Canada Native Plants: Fraxinus profunda
- Harms, W. R. (1990). "Fraxinus profunda". In Burns, Russell M.; Honkala, Barbara H. (eds.). Hardwoods. Silvics of North America. Washington, D.C.: United States Forest Service (USFS), United States Department of Agriculture (USDA). 2 – via Southern Research Station (www.srs.fs.fed.us).
- Ojibway Nature Centre: Trees of Essex County, Ontario
- "Plants Profile for Fraxinus profunda (pumpkin ash)". plants.sc.egov.usda.gov. Retrieved 2020-11-18.
- "Fraxinus profunda | International Plant Names Index". www.ipni.org. Retrieved 2020-11-18.
- Phytoneuron. 2010–32. Fort Worth, TX: Guy L. Nesom. 2010.
- Michigan Natural Features Inventory: Fraxinus profunda (pdf file) Archived 2008-01-07 at the Wayback Machine
- Missouri State Champion Trees
- Virtual Herbarium of the Chicago Region: Fraxinus profunda Archived 2006-10-04 at the Wayback Machine
- Stevens, Micah E.; Pijut, Paula M. (2012-01-01). "Hypocotyl derived in vitro regeneration of pumpkin ash (Fraxinus profunda)". Plant Cell, Tissue and Organ Culture. 108 (1): 129–135. doi:10.1007/s11240-011-0021-9. ISSN 1573-5044.