{{Short description|Species of ash}} {{Speciesbox | image = Fraxinus profunda Niagara ON.jpg | image_caption = Pumpkin ash in a hardwood swamp in Ontario, Canada. | status = CR | status_system = IUCN3.1 | status_ref = <ref name="iucn status 11 November 2021">{{cite iucn |author=Westwood, M. |author2=Jerome, D. |author3=Oldfield, S. |author4=Romero-Severson, J. |date=2017 |title=''Fraxinus profunda'' |volume=2017 |article-number=e.T61919022A113525283 |doi=10.2305/IUCN.UK.2017-2.RLTS.T61919022A113525283.en |access-date=11 November 2021}}</ref> | genus = Fraxinus | parent = Fraxinus sect. Melioides | species = profunda | authority = (Bush) Bush | range_map = Fraxinus profunda range map 1.png | range_map_caption = Natural range of ''Fraxinus profunda'' | range_map2 = Fraxinus profunda range map 4.png | range_map2_caption = Close-up of natural range of ''Fraxinus profunda'' | synonyms = ''Fraxinus tomentosa'' <small>F.Michx.</small> }}
'''''Fraxinus profunda''''', the '''pumpkin ash''', is a species of ash (''Fraxinus'') native to eastern North America, where it has a scattered distribution on the Atlantic coastal plain and interior lowland river valleys from the Lake Erie basin in Ontario and New York west to Illinois, southwest to Missouri and southeast to northern Florida.<ref name="grin">{{GRIN | accessdate = 14 January 2018}}</ref><ref name="cnp">Canada Native Plants: [http://www.evergreen.ca/nativeplants/search/view-plant.php?ID=02709 ''Fraxinus profunda'']</ref><ref name="usfs">{{Silvics |volume=2 |genus=Fraxinus |species=profunda |first=W. R. |last=Harms}}</ref><ref name="onc">Ojibway Nature Centre: [http://www.ojibway.ca/trees.htm Trees of Essex County, Ontario]</ref><ref name=":3">Committee on the Status of Endangered Wildlife in Canada (COSEWIC). 2022. COSEWIC Assessment and Status Report on the Pumpkin Ash, ''Fraxinus profunda'', in Canada. Environment and Climate Change Canada, Ottawa.</ref> It grows in bottomland habitats, such as swamps, floodplains and riverbanks. It is threatened by the emerald ash borer (''Agrilus planipennis''), an invasive insect which has caused widespread destruction of ash trees in eastern North America.
== Taxonomy == Pumpkin ash is a member of the olive family (Oleaceae) and is placed in section Melioides of the genus ''Fraxinus''.<ref name=":1" /> Historically, it was frequently called ''Fraxinus tomentosa'' Michx., but since Michaux used this name interchangeably with the species now known as green ash (''F. pennsylvanica''), the name ''Fraxinus profunda'', which was applied by Benjamin Franklin Bush in 1901, was given precedence.<ref name=":1" />
Pumpkin ash is hexaploid (n=138) and has been hypothesized to have originated as a fertile hybrid between green ash and white ash (''F. americana''), but this remains unproven''.''<ref>{{Cite journal |last=Wallander |first=Eva |date=2008-06-01 |title=Systematics of Fraxinus (Oleaceae) and evolution of dioecy |journal=Plant Systematics and Evolution |language=en |volume=273 |issue=1 |pages=25–49 |doi=10.1007/s00606-008-0005-3 |issn=1615-6110}}</ref><ref name=":1">{{Cite book|url=https://www.biodiversitylibrary.org/item/125914|title=Phytoneuron|date=2010|publisher=Guy L. Nesom|volume=2010-32|location=Fort Worth, TX}}</ref>
The name pumpkin ash originates from early European settlers in Arkansas and refers to the swollen trunk bases which this tree often produces in very wet habitats.<ref name="usfs" />
== Morphology == Pumpkin ash is a medium-sized deciduous tree reaching {{convert|12|to|30|m|ft|sp=us}} tall with a trunk up to 1 meter in diameter, although exceptional trees can reach {{convert|50|m|ft|abbr=off|sp=us}} tall with a {{convert|4.7|m|ft|abbr=off|sp=us}} diameter trunk.<ref name="msct">{{Cite web |url=http://mdc.mo.gov/sites/default/files/resources/2010/05/missouri_state_champion_trees_12-02-14.pdf |title=Missouri State Champion Trees |access-date=2014-12-17 |archive-date=2014-12-17 |archive-url=https://web.archive.org/web/20141217091308/http://mdc.mo.gov/sites/default/files/resources/2010/05/missouri_state_champion_trees_12-02-14.pdf }}</ref> Important morphological characteristics of pumpkin ash include:
* bark: gray, thick and fissured with a diamond pattern on mature trees * buds: dark brown to blackish, with a velvety texture * leaves: {{convert|25|to|40|cm|in|abbr=off|sp=us}} long, oppositely-arranged, pinnately compound with 7 to 9 leaflets; leaflets {{convert|8|to|20|cm|in|abbr=off|sp=us}} long and {{convert|5|to|8|cm|in|abbr=off|sp=us}} broad, with smooth or obscurely serrated margins and short petiolules; abaxial (lower) surfaces are tomentose and lack a dense covering of papillae (visible at >40x magnification) * flowers: wind-pollinated, purplish-green, lacking a corolla; borne in panicles; blooming in spring shortly before the emergence of leaves * fruit: samaras {{convert|5|to|8|cm|in|abbr=off|sp=us}} long, comprising a single seed with an elongated apical wing {{convert|9|mm|in|abbr=off}} broad.<ref name="usfs" /><ref name="onc" /><ref name="vplants">Virtual Herbarium of the Chicago Region: [http://www.vplants.org/plants/species/species.jsp?gid=17018 ''Fraxinus profunda''] {{Webarchive|url=https://web.archive.org/web/20061004085840/http://www.vplants.org/plants/species/species.jsp?gid=17018|date=2006-10-04}}</ref><ref name="mnfi">Michigan Natural Features Inventory: [http://web4.msue.msu.edu/mnfi/abstracts/botany/Fraxinus_profunda.pdf ''Fraxinus profunda'' (pdf file)] {{Webarchive|url=https://web.archive.org/web/20080107182505/http://web4.msue.msu.edu/mnfi/abstracts/botany/Fraxinus_profunda.pdf|date=2008-01-07}}</ref>
Like other species in the section Melioides, pumpkin ash is dioecious, with male and female flowers produced on separate individuals.<ref>{{cite journal|doi=10.1007/s00606-008-0005-3|title=Systematics of ''Fraxinus'' (Oleaceae) and evolution of dioecy|year=2008|last1=Wallander|first1=Eva|journal=Plant Systematics and Evolution|volume=273|issue=1–2|pages=25–49|s2cid=24152294}}</ref>
Pumpkin ash trees frequently produce bulbous swollen trunk bases and this is sometimes cited as a diagnostic feature of this species. However, not all pumpkin ash trees exhibit this feature and other ash species, such as green ash, can also produce swollen trunks in very wet habitats.<ref name=":3" /><ref name="usfs" />
== Reproduction == Pumpkin ash attains sexual maturity and begins producing fruit at approximately ten years of age.<ref name="usfs" /> The seeds develop during the summer and are dropped in the early fall.<ref name="usfs" /> The winged samaras are adapted to wind dispersal, but pumpkin ash seeds are uniquely adapted to dispersal by water and can survive submersion for several months.<ref name="usfs" />
Seedlings thrive in moist soils in canopy openings and are sensitive to shade.<ref name="usfs" /> Young trees are extremely fast growing and can quickly attain a height where they compete with mature trees.<ref name="usfs" />
==Ecology== Pumpkin ash occurs primarily in swamps, floodplains and other wet bottomland habitats.<ref name="usfs" /> Along with other ashes, it is a food plant for the larvae of several species of Lepidoptera (see List of Lepidoptera that feed on ashes).
Pumpkin ash is threatened by the emerald ash borer, an invasive insect which has destroyed large numbers of ash trees in eastern North America.<ref name="vplants" /><ref name=":3" /> In 2017, the IUCN assessed the pumpkin ash as Critically Endangered, due to observed massive population declines over most of its range. In 2021, pumpkin ash was listed as endangered in Canada under the ''Species at Risk Act'', 2002.<ref name=":3" />
== Distribution == Pumpkin ash has a discontinuous range in eastern North America, where it occurs mainly in swamps and river bottoms of the Atlantic coastal plain, Mississippi valley and lower Great Lakes basin, but is conspicuously absent from regions in between, such as the Appalachian Mountains.<ref name="usfs" /><ref name=":3" /><ref name=":1" /> As a result of widespread damage by the emerald ash borer, pumpkin ash is near extirpation in North Carolina, South Carolina and Florida, and is critically endangered in Canada.<ref name=":3" />
=== Climate === Areas where pumpkin ash trees are found typically have an average rainfall of {{convert|101|to|122|cm|in|abbr=off|sp=us}} of rain per year.<ref name="usfs" /> During the growing season, from March to September, the average rainfall is around {{convert|66|cm|in|abbr=off}}. Pumpkin ash can tolerate temperatures as low as -31 degrees Celsius (-24 degrees Fahrenheit).<ref name=":0">{{Cite PLANTS |symbol=FRPR |taxon=Fraxinus profunda |access-date=2020-11-18 }}</ref>
=== Soils === Pumpkin ash grows in saturated wetland soils, including sites which are flooded year-round.<ref name="usfs" /> Saplings tend to grow slower in very wet conditions compared to higher-elevation microsites.<ref name="usfs" />
== 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''.<ref name="usfs" /> 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.<ref name="usfs" /> In addition to being used as lumber, the wood of pumpkin ash trees can also be used in tools such as stocks or handles.<ref name=":2">{{Cite journal|last1=Stevens|first1=Micah E.|last2=Pijut|first2=Paula M.|date=2012-01-01|title=Hypocotyl derived in vitro regeneration of pumpkin ash (Fraxinus profunda)|journal=Plant Cell, Tissue and Organ Culture |language=en|volume=108|issue=1|pages=129–135|doi=10.1007/s11240-011-0021-9|s2cid=401589|issn=1573-5044}}</ref> The wood can also be used as lumber, naval store products, and nursery stock products.<ref name=":0" />
== Gallery == <gallery> File:Fraxinus profunda Essex ON.jpg|Canopy of a pumpkin ash affected by emerald ash borer in Essex County, Ontario, Canada. File:Fraxinus profunda Elgin ON.jpg|Developing samaras of a pumpkin ash in Elgin County, Ontario, Canada. File:Fraxinus profunda Lambton ON.jpg|Rachis, petiolule and abaxial leaflet surface of a pumpkin ash leaf from Lambton County, Ontario, Canada. File:Fraxinus profunda, RBGE 2008.jpg|Pumpkin ash in cultivation at Royal Botanic Garden Edinburgh. </gallery>
==References== {{Commons category|Fraxinus profunda}} {{Reflist}}
{{Taxonbar|from=Q5494018}}
profunda Category:Trees of Northern America Category:Plants described in 1901 Category:Dioecious plants