| 0 | Ames 36329 | Country Club | Maclura pomifera (Raf.) C. K. Schneid. | Iowa, United States | NC7 |  | Not Available | 2025 | COLLECTED | 2020 | Des Moines Golf and County Club (1600 Jordan Creek Parkway - West Des Moines, Iowa 50266) just southwest of University Avenue and Jordan Creek Parkway intersection, T78N R26W NW ¼ Sec. 2. | 41.59634700, -93.82323000 | 307 | Previously (historically) a fence-line. Specimen retained and incorporated into golfcourse. | Clone | The native range for Osage-orange is reported from eastern Texas, southeastern Oklahoma, southwestern Arkansas, and the northwestern corner of Louisiana (Little, 1971). Historically and presently known for its extreme value as bow-wood and fence posts, Osage-orange represents one of the most widely planted tree species in the lower 48 US states as a living fence starting in the mid-1800's, in the late 1900's as a landscape tree for difficult sites, and most recently it's chemical properties. Detailed history of Osage-orange and it's economic uses are well documented (Smith and Perino, 1981 and J. T. Winberry 1979). Osage wood is highly-prized for its use as fence posts (both living and non-living) and durable wood for wood working. Osage is an extremely drought and heat tolerant tree and is recommended for use in USDA cold-hardiness zones 5b or warmer. Although the species is commonly known for it's stout thorns and large, globular fruits, the species is dioecious and the degree of thorns on individual genotypes can be extremely variable. This accession represents a clonal selection collected from a specimen growing in central Iowa (Dallas County) that is confirmed as a thornless, male. It has been tentatively named Country Club as the original specimen is located on the grounds of the Des Moines Golf & County Club. Aerial photograph from the 1930's show the specimen's obvious presence at that time. It is estimated to be approximately 150 years in age as of 2025. In 2009, the specimen was estimated by Andrew P. Schmitz (The Brenton Arboretum) and Guy Sternberg (Starhill Forest Arboretum) at 42 feet in height and an average spread of 60 feet. | 2191633 | Ames 36329 |
| 1 | Ames 36251 | JDC/UT/2024/008/1130 | Ulmus thomasii Sarg. | Minnesota, United States | NC7 |  | | 2024 | COLLECTED | 06/05/2024 | Near southeast edge of Kasota Lake approximately 9.0 miles east, southeast of Willmar, T119N R34W SE 1/4 NE 1/4 Sec. 36 and also Robbins Island Park in Wilmar, T119N R35W Sec. 11. | 45.07399600, -94.88484100 | 352 | Deciduous woods | Wild material | Ulmus thomasii (Rock elm) is an underutilized tree species both in conservation and in the urban landscape. Described by Charles Sprague Sargent (first director for the Arnold Arborteum) as "heavy, hard, very strong and tough, closely grained, and susceptible of receiving a beautiful polish". Historically noted for a variety of uses in woodworking including furniture, heavy agricultural implements, timber frame buildings, pianos, hockey sticks, and hand tools. Ulmus thomasii is extremely drought tolerant, adaptable to very calcareous soils, and compared to U. americana or U. rubra has a very conservative growth rate requiring minimal attention in regards to pruning. Rock elm naturally tends to develop into a nice structural specimen in the landscape, unlike other fast growing cultivars in the nursery trade needing frequent attention. Rock elm has very fissured bark and is well known for maintaining a strong central leader resulting in a very attractive, pyramidal form. Despite many literature sources stating that "wings" on the stems are a key identifiying characteristic, this trait is not reliable and many genotypes may completely lack "wings" on the stems. While growth habit and morphology of dormant buds (very pointy) are good traits to help aid in identification, fruits are the best way to confirm identity. Fruits are densly pubescent, often described as "inflated" and generally reach maturity a couple weeks after Ulmus rubra and Ulmus americana. U. thomasii inflorescences are rather distinguishable from other Ulmus in being pendulous. Fruits are extremely prized treats for many birds, where fruits are often "robbed" prior to full maturity. Fruits are also highly prized by many other animals such as mice, squirrels, chipmunks, turkeys, etc. and are generally consumed within hours after fruit abscission. The native range of Ulmus thomasii is concentrated in the northeastern United States and into Canada with disjunct populations documented in northwestern Missouri and northwestern Arkansas. In the 1895 Silva of North America (vol. 7) it was stated that, “The value of the wood of the Rock Elm threatens its extinction and most of the large trees have already been cut.” Today, while rock elm is rather rare, especially in areas near the edges of its range, many states list the species as endangered or threatened warranting preservation efforts. Genetics of this accession would be representative of the species northwestern edge of its native range. Majority of specimens noted did not have characteristic "wings" on the stems and measured approximately 20" DBH or more with a few specimens nearing 30". Heights estimated between 70-90'. Rock elm in this area could be classified as locally abundant. | 2167953 | Ames 36251 |
| 2 | Ames 36073 | JDC/UT/2022/028/1009 | Ulmus thomasii Sarg. | Iowa, United States | NC7 |  | | 2023 | COLLECTED | 06/05/2023 | Ledges State Park approximately 4.75 miles south of Boone, T83N R26W (Madrid NW Quad.) near center of SE ¼ Sec. 16 and also NW ¼ SW ¼ Sec. 21. | 41.99780200, -93.87967900 | 288 | Moist deciduous woods typically on mid-slopes to base of slopes and also well-drained floodplains. | Wild material | Ulmus thomasii (Rock elm) is an underutilized tree species both in conservation and in the urban landscape. Charles Sprague Sargent (first director of the Arnold Arboretum of Harvard University, Boston, MA) described the wood of Rock Elm as "heavy, hard, very strong and tough, closely grained, and susceptible of receiving a beautiful polish". Historically noted for a variety of uses in woodworking including furniture, heavy agricultural implements, timber frame buildings, pianos, hockey sticks, and hand tools. U. thomasii is extremely drought tolerant, adaptable to very calcareous soils, and compared to U. americana or U. rubra has a very conservative growth rate requiring minimal attention in regards to pruning. Rock elm naturally tends to develop into a nice structural specimen in the landscape, unlike other fast growing U. americana cultivars in the nursery trade needing frequent attention. Rock elm has very fissured bark and is well known for maintaining a strong central leader resulting in a very attractive, pyramidal form. Despite many literature sources stating that "wings" on the stems are a key identifiying characteristic, this trait is not reliable and many genotypes may completely lack "wings" on the stems. While growth habit and morphology of dormant buds (very pointy) are good traits to help aid in identification, fruits are the best way to confirm identity. Fruits are densly pubescent, often described as "inflated" and generally reach maturity a couple weeks after U. rubra and U. americana. U. thomasii flowering in central Iowa typically occurs the last week in April into the first week in May and are rather distinguishable from other Ulmus in being pendulous. Fruits are extremely prized treats for many birds, where fruits are often "robbed" prior to full maturity. Fruits are also highly prized by many other animals such as mice, squirrels, chipmunks, turkeys, etc. and are generally consumed within hours after fruit abscission. The native range of U. thomasii is concentrated in the northeastern United States and into Canada with disjunct populations documented in northwestern Missouri and northwestern Arkansas (Little, E. L. Jr. 1971). In the 1895 Silva of North America (vol. 7) it was stated that, “The value of the wood of the Rock Elm threatens its extinction and most of the large trees have already been cut.” Today, since rock elm is rather rare, especially in areas near the edges of its range, many states list the species as endangered or threatened warranting preservation efforts. Genetics of this accession would be representative of the species southwestern edge of its native range. Out of approximately 100 specimens noted throughout Ledges State Park only 1-2% of specimens had characteristic "wings" on the stems. Research was executed (Moore, P., 2024) involving the core sampling of U. thomasii and U. americana specimens in Ledges State Park to make growth ring widths and basal area increment comparisons. Results determined that the average age of cored trees U. thomasii (n=4) and U. americana (n=4) of both species was roughly 80 years, excluding the exceptional case of tree #007 (Ames 36073 23ncao02 SD). Tree #007 was aged at 300 years of age and currently (2025) ranks as the 14th largest U. thomasii in Iowa measuring 21" DBH with a height of 75' 5" and a spread of 43' 5" totalling 152.21 points (Rouw, M., personal communication, 4 May 2022). The computed mean density at 𝑀𝑀 = 12% for U. thomasii was 0.80 g/cm3, and for U. americana was 0.672 g/cm3. These values are both higher than the representative values inferred from the Woods Database which are 0.755 g/cm3 for U. thomasii and 0.56 g/cm3 for U. americana. To date, there is little to no information regarding U. thomasii resistance to Dutch Elm Disease. Collections of U. thomasii at the Arnold Arboretum have over-time succumbed to DED (Pruka, B., 2016). However, data recorded by Moore (2024) indicates that U. thomasii growing in central Iowa can surpass 300 years in age verifying it's long-term utilization in the landscape. | 2142915 | Ames 36073 |
| 3 | Ames 36138 | Muscatatuck NWR | Populus heterophylla L. | Indiana, United States | NC7 |  | | 2023 | COLLECTED | 05/30/2023 | Muscatatuck National Wildlife Refuge located 4.37 miles east, southeast of Seymour, T6N R6E SW 1/4 Sec. 24 | 38.94292000, -85.81076600 | 159 | Edge of stagnant swamp along road. Soils rather mucky/heavy clay. | Wild material | Native to North America, this deciduous tree has a native range that covers the Atlantic coastal plain concentrated in the Carolinas and also along the Mississippi and Ohio Rivers along with various, tiny disjunct populations widely scattered across the southeast U.S. (Little, 1971). As an obligate wetland plant, the soils that this species inhabits is typically heavy clay (ranging 24 to 65%) and slightly acidic (soil pH ranges from 4.6 to 5.9) (Johnson 1990). Typical habitat is bottomlands/floodplains that generally have standing, shallow water. Sites that are often too wet for P. deltoides are suitable for P. heterophylla. Swamp Cottonwood can reach 10-20 meters in height and generally has an upright, rounded form. Broadly ovate leaves are rather large reaching up to 25 cm in length and nearly 15 cm wide with abaxial surfaces usually pubescent to partially glabrate. As with many other species in Salicaceae, P. heterophylla is dioecious with staminate and pistillate catkins appearing in early spring and reaching up to 10 and 15 cm in length, respectively. Seeds are dispersed in spring through early summer. Swamp Cottonwood is distinguishable from other Populus largely due to the distinctly cordate leaf bases and distinctive orange-brown pith in young twigs (McMaster 2003). Ornamental characteristics include golden yellow fall color. This taxon is essentially non-existent in the nursery trade and extremely rare in botanical garden and arboretum collections. Due to this species ability to grow in anaerobic, soils heavy in clay, this species may perform well in the typical urban landscape. Its potential to withstand extreme, drought despite being an obligate wetland plant may be similar to that found in Taxodium distichum. Genetics of this accession were collected in southern Indiana. Specimens sampled in nature were approximately 40-50' in height and were clonally (vegetative) spreading by rhizomes. | 2158343 | Ames 36138 |
| 4 | Ames 36025 | AS/PO/2023/012/222 | Platanus occidentalis L. | Wisconsin, United States | NC7 |  | Not Available | 2023 | | | | | | | Wild material | The native range of Platanus occidentalis is concentrated in the southeastern United States extending north into central New York and west to central Iowa and also a small area of southwest Wisconsin along the Wisconsin River floodplain (Little, E. L. Jr. 1971). The Wisconsin Natural Heritage Inventory Program currently (2023) lists this taxon in Wisconsin as a species of concern with a state rank of S2 (Imperiled in Wisconsin due to a restricted range, few populations or occurrences, steep declines, severe threats, or other factors.) This accession represents genetics (Richland and Iowa Counties, WI) from the extreme northern edge of the species native range. Specimens sampled in nature were multi-trunked specimens resulting from logging that occurred in the early 1900's. Specimens exhibiting attractive white bark. Specimen #222-2 had rather upright (e.g. 60 degree angled) branches. | 2141558 | Ames 36025 |
| 5 | Ames 36028 | JDC/MP/2023/014/1046 | Maclura pomifera (Raf.) C. K. Schneid. | Iowa, United States | NC7 | _thumbnail.jpg "Click for 3 image(s) for this accession.") | | 2022 | COLLECTED | 11/02/2022 | Located 8.0 miles northeast of Boone where Montgomery Creek crosses V Avenue, T85N R25W NW 1/4 SW 1/4 Sec. 34 | 42.12911400, -93.75509100 | 295 | Previously grazed pasture. | Uncertain improvement status | The native range for Osage-orange is reported from eastern Texas, southeastern Oklahoma, southwestern Arkansas, and the northwestern corner of Louisiana (Little, 1971). Historically and presently known for its extreme value as bow-wood and fence posts, Osage-orange represents one of the most widely planted tree species in the lower 48 US states as a living fence starting in the mid-1800's, in the late 1900's as a landscape tree for difficult sites, and most recently it's chemical properties. Detailed history of Osage-orange and it's economic uses are well documented (Smith and Perino, 1981 and J. T. Winberry 1979). Osage wood is highly-prized for its use as fence posts (both living and non-living) and durable wood for wood working. Osage is an extremely drought and heat tolerant tree and is recommended for use in USDA cold-hardiness zones 5b or warmer. Although the species is commonly known for it's stout thorns and large, globular fruits, the species is dioecious and the degree of thorns on individual genotypes can be extremely variable. This accession represents genetics collected from a naturalized population in central Iowa (Boone County - Harrison Township). Majority of specimens sampled averaged approximately 40-45’ in height with multiple (e.g. 1-5) trunks. The collection site represents a recognized Iowa Century Farm awarded in 1976 that was originally settled by Andrew Nelson and then purchased on 24 October 1874 for the amount of '9.00 per acre by Lester S. Carlson. According to Samuel Keith Carlson (grandson to Lester S. Carlson), in the 1930's-1940's there was a fence line plus a few additional specimens of significant size that were possibly planted by Lester S. Carlson in the 1870's or the previous owner during "hedge mania" in the 1850's. In the 1950's the original trees at the Carlson farm were removed, but the progeny have persisted throughout the woods and adjacent pasture areas and continue to spread. A corner fence post of Osage that was set in 1874 by Lester S. Carlson shortly after purchasing the property still remains (see image). Majority of the specimens in this population are nearly thornless or with relatively few thorns. Fruit sizes range between 70-90 mm in diameter with seed lengths ranging from 6.99 (min) to 11.687 (max) with the average length of 50 seeds at 9.36 mm. At time of collection (2 November 2022) approximately 20% of specimens were at peak, yellow fall color, while remaining specimens were still green. | 2141741 | Ames 36028 |
| 6 | Ames 34028 | NA 84709 | Monarda didyma L. | Maryland, United States | NC7 |  | | 2017 | COLLECTED | 10/09/2017 | Savage River State Forest along Elk Lick Run Creek located approximately 5.9 miles southeast of Grantsville just off Westernport Road 2.5 miles south of intersection with Lower New Germany Road, Garrett County. | 39.61595000, -79.11066900 | 694 | Partial shade along disturbed roadside with steep slope on both sides of road near edge of creek. Mowed annually. Moist, rocky clay-loam soils. | Wild material | Specimens measuring approximately 18-24" in height with some mildew present at time of collection (10/09/2017). Peak bloom occurred near 07/25/2017. | 1954317 | Ames 34028 |
| 7 | Ames 33752 | Ames 33752 | Maclura pomifera (Raf.) C. K. Schneid. | Iowa, United States | NC7 |  | | 2016 | COLLECTED | 10/05/2016 | Deer Creek watershed, T80N R23W E1/2 Sec. 18. | 41.73813000, -93.56296400 | 295 | Mixed deciduous woods, distrubed areas and also managed areas. Gentle slopes and wetlands | Uncertain improvement status | The native range for Osage-orange is reported from eastern Texas, southeastern Oklahoma, southwestern Arkansas, and the northwestern corner of Louisiana (Little, 1971). Historically and presently known for its extreme value as bow-wood and fence posts, Osage-orange represents one of the most widely planted tree species in the lower 48 US states as a living fence starting in the mid-1800's, in the late 1900's as a landscape tree for difficult sites, and most recently it's chemical properties. Detailed history of Osage-orange and it's economic uses are well documented (Smith and Perino, 1981 and J. T. Winberry 1979). Osage wood is highly-prized for its use as fence posts (both living and non-living) and durable wood for wood working. Osage is an extremely drought and heat tolerant tree and is recommended for use in USDA cold-hardiness zones 5b or warmer. Although the species is commonly known for it's stout thorns and large, globular fruits, the species is dioecious and the degree of thorns on individual genotypes can be extremely variable. This collection represents germplasm from a naturalizing, reproductive population collected in central Iowa (Polk County). Majority of specimens averaged approximately 40-50’ in height with multiple (e.g. 4-5) trunks. Specimens 03-1 and 03-2 were upright in form with tighter branch angles, while 03-10 was the widest spreading of all trees. Some yellow fall color apparent at time of fruit collection (10/05/2016). Size of fruits ranged from 9.00 to 10.75 inches circumference except for tree 03-5 with fruits averaging 7.33 inches circumference. | 1942949 | Ames 33752 |
| 8 | Ames 33736 | JDC/BA/2016/028/743 | Betula alleghaniensis Britton | Iowa, United States | NC7 |  | | 2016 | COLLECTED | 09/02/2016 | Fallen Rock State Preserve approximately 1.9 miles southwest of Steamboat Rock, T88N R19W NW ¼ Sec. 32. | 42.39459000, -93.09423600 | 310 | High-quality, native, mesic deciduous woods on loose, loamy sandstone amongst very large boulders. North-facing with variable 10-50 degree slopes. Majority of specimens located at base of bluff or near water’s edge (Iowa River). | Wild material | The native range of Betula alleghaniensis is concentrated in the northeastern U.S. with disjunct populations in Iowa (Little, 1971). This accession represents a collection of Betula alleghaniensis germplasm from the extreme western edge of the species native range. The next closest occurrence is in Mitchell County, Iowa (60 miles). As of 2025, two trees at Fallen Rock State Preserve currently represent the state of Iowa's 1st and 2nd largest yellow birch specimens measuring 22.76" DBH; 70.83' height; 40' average crow spread (151.83 points) and 17.18" DBH; 65.33' height; 33.75' average crow spread (127.76 points), respectively (Rouw, M., personal communication, 13 May 2018). | 1942689 | Ames 33736 |
| 9 | Ames 33357 | JDC/UT/2016/018/733 | Ulmus thomasii Sarg. | Iowa, United States | NC7 |  | | 2016 | COLLECTED | 06/03/2016 | Malanaphy Springs State Preserve just northwest of Decorah, T99N R8W SW ¼ NW ¼ SE ¼ Sec. 31 | 43.34713800, -91.83840000 | 302 | Deciduous woods. Rocky substrate. 20 degree northwest-facing slope | Wild material | Ulmus thomasii (Rock elm) is an underutilized tree species both in conservation and in the urban landscape. Charles Sprague Sargent (first director of the Arnold Arboretum of Harvard University, Boston, MA) described the wood of Rock Elm as "heavy, hard, very strong and tough, closely grained, and susceptible of receiving a beautiful polish". Historically noted for a variety of uses in woodworking including furniture, heavy agricultural implements, timber frame buildings, pianos, hockey sticks, and hand tools. U. thomasii is extremely drought tolerant, adaptable to very calcareous soils, and compared to U. americana or U. rubra has a very conservative growth rate requiring minimal attention in regards to pruning. Rock elm naturally tends to develop into a nice structural specimen in the landscape, unlike other fast growing U. americana cultivars in the nursery trade needing frequent attention. Rock elm has very fissured bark and is well known for maintaining a strong central leader resulting in a very attractive, pyramidal form. Despite many literature sources stating that "wings" on the stems are a key identifiying characteristic, this trait is not reliable and many genotypes may completely lack "wings" on the stems. While growth habit and morphology of dormant buds (very pointy) are good traits to help aid in identification, fruits are the best way to confirm identity. Fruits are densly pubescent, often described as "inflated" and generally reach maturity a couple weeks after U. rubra and U. americana. U. thomasii flowering in central Iowa typically occurs the last week in April into the first week in May and are rather distinguishable from other Ulmus in being pendulous. Fruits are extremely prized treats for many birds, where fruits are often "robbed" prior to full maturity. Fruits are also highly prized by many other animals such as mice, squirrels, chipmunks, turkeys, etc. and are generally consumed within hours after fruit abscission. The native range of U. thomasii is concentrated in the northeastern United States and into Canada with disjunct populations documented in northwestern Missouri and northwestern Arkansas (Little, E. L. Jr. 1971). In the 1895 Silva of North America (vol. 7) it was stated that, “The value of the wood of the Rock Elm threatens its extinction and most of the large trees have already been cut.” Today, since rock elm is rather rare, especially in areas near the edges of its range, many states list the species as endangered or threatened warranting preservation efforts. This accession represents genetics from northeast Iowa (Winneshiek County). In an assessment of some of the largest Ulmus thomasii (native and cultivated) across Iowa, four of the nine largest specimens in Iowa are present in Malanaphy Springs State Preserve where this accession was sampled. The second largest U. thomasii in the state located in Malanaphy Springs was measured on 22 May 2020 with a circumference of 6.42', height of 86.58', and an average crown spread of 68.00' (180 points) (Rouw, M., personal communication, 8 February 2021). | 1940580 | Ames 33357 |
| 10 | Ames 32758 | Fallen Rock | Pinus strobus L. | Iowa, United States | NC7 |  | | 2014 | COLLECTED | 08/21/2014 | Fallen Rock State Preserve and adjacent private property just north of Eldora, T88N R19W SW ¼ Sec. 28 and N ¼ Sec. 32 and also T87N R19W N ½ Sec. 5. | 42.39548900, -93.09165200 | 311 | Cool moist woods. Slopes averaging 60 degrees. Northern and eastern aspects. Localized to bluffs above Iowa River. | Wild material | The native range of Pinus strobus is concentrated in the northeastern United States extending south into the northern edge of Georgia and west to central Minnesota. In Iowa, scattered native populations exist in a few northeastern counties as well as small disjunct populations in central and southeastern counties (Little, 1971). This accession includes genetics from legacy mother trees located in Fallen Rock State Preserve and nearby private property to the south. This area is near Pine Lake State Park, which in 2009 was devastated by a severe hailstorm of "supersized softballs" resulting in significant cambial damage to many species of trees. Damage to the majority of P. strobus specimens throughout the area was so severe that losses occurred immediately. Additional losses in subsequent years continued to occur likely due to additional stress by drought and destruction by bark beetles. The loss of approximately 75% of the P. strobus specimens at Pine Lake State Park was attributed to the 2009 hailstorm prompted efforts to preserve genetics of the white pines here. In 2014, specimens in parts of Pine Lake State Park and also one specimen at Fallen Rock State Preserve were sampled (Carstens, J.) as seeds from specimens ranging in size from 9.25 inches to 31.75 inches d.b.h. However, in 2021, it was determined (Place, A. pers. comm. 24 February 2021 and Carstens, J. & Sherwood, A., pers. observations 1 March 2021) that likely most if not all of the specimens in Pine Lake State Park are planted specimens of unknown origin because P. strobus specimens located at the far east end of Lower Lake (south side) were noted (Carstens and Sherwood, pers. observations 1 March 2021) growing with uncharacteristic associated taxa including Acer saccharinum and Gymnocladus dioicus. Two documents that support these observations includes: 1. Letter signed by Louis H. Pammel (March 25, 1925) to G.B. McDonald of the Iowa State University Forestry Department asking for 200 white pine to be planted at Pine Lake. 2. "Trees to Be Set Out by CCC Workers" in the Eldora Herald (May 9, 1935) referencing the CCC (Civilian Conservation Corps) to plant “1,000 white pines at Pine Lake State Park". Therefore, if obtained, increment borer measurements of specimens that are 94 years of age at present (2014) or older would suggest those as being true, native remnants. Documents that supports the position of remnant specimens at Fallen Rock State Preserve includes: 1. "Picturesque Drives About Eldora", in the Eldora Herald (December 8, 1910) by Clara Estabrook stating "Miss Stoddard of the Iowa Falls school says these (only 11 trees left) are the only native pines (those restricted to the sandstone cliffs) found in Hardin County" and suggested a movement to have them preserved. 2. Forest Flora of Hardin County (1899) by L. H. Pammel stating that the Iowa valley serves as the western limits for white pine and also refers to David D. Owen's geological report from 1839 indicating the occurrences of white pines on the summits of the hills along the Iowa River. In addition, a photo of white pines growing at Steamboat Rock taken by L. H. Pammel was featured on the front page of the 1919 report of the State Board of Conservation titled "Iowa Parks: Conservation of Iowa Historic, Scenic and Scientific Areas." Due to the significant presence of planted specimens of unknown origin in Pine Lake State Park and surrounding private properties, samples collected in 2014 as seeds may likely contain genetics (pollen donors) from specimens of unknown origin. This resulted in the resampling of specimens in 2021 (USFS - IAHA#'s) and 2023 as dormant scions that are from locations known to be untouched by the CCC and thus represent true, remnant specimens. To date (2021), there are only eight legacy specimens left in this population (four specimens at Fallen Rock State Preserve and four specimens at the nearby private property). The largest specimen of P. strobus (Ames 32758) is #IAHA-08 located at (42.395489, -93.091652) measuring (13 May 2018) 35.65" DBH with a height of 78.33' and a spread of 26' totalling 197 points (Rouw, M., personal communication, 8 February 2023). This germplasm represents the southwestern most population of native P. strobus in Iowa and one of the western most populations in North America. Germplasm likely is adapted to Midwestern climatic extremes and potentially very drought tolerant in comparison to other provenances from the eastern or northeastern U.S. | 1921270 | Ames 32758 |
| 11 | Ames 32093 | JDC/CC/2013/048/492 | Carpinus caroliniana Walter | Iowa, United States | NC7 | | | 2013 | COLLECTED | 10/25/2013 | Ledges State Park mostly from specimens adjacent to Peas Creek, NE ¼ of SE ¼ of Sec. 16, T83N R26W, Des Moines Quad. | 41.99910000, -93.87880000 | 328 | North and northwest-facing slopes. | Wild material | The native range of Carpinus caroliniana is concentrated in the eastern half of the U.S. with a very small disjunct population in central Iowa (Little, 1971). This accession represents a collection of C. caroliniana germplasm from the extreme western edge of the species native range, specifically the central Iowa disjunct population at Ledges State Park. The next closest occurrence is in eastern Iowa (100-150 miles). As of 2025, one specimen at Ledges State Park (McCoy Wildlife Area) currently represents the state of Iowa's largest C. caroliniana specimen measuring 6.68" DBH, 41.67’ in height, and 23.75’ average crown spread for a total of 68.608 points (Rouw, M., personal communication, 4 May 2022). This accession does include genotypes that do tend to sucker/form clonal colonies. Fall color (red/orange) tends to peak in the last week of October (central Iowa) with peak fruiting occurring simultaneously. Bark smooth, grey. | 1914037 | Ames 32093 |
| 12 | Ames 27341 | JDC/UT/2017/021/775 | Ulmus thomasii Sarg. | Nebraska, United States | NC7 |  | | 2003 | COLLECTED | | Ponca State Park just north of Ponca approximately 2.75 miles T30N R6E N1/3 SE 1/4 Sec. 3 | 42.60173800, -96.71222100 | 383 | Eastern slopes and ridges of loess bluffs | Wild material | Ulmus thomasii (Rock elm) is an underutilized tree species both in conservation and in the urban landscape. Charles Sprague Sargent (first director of the Arnold Arboretum of Harvard University, Boston, MA) described the wood of Rock Elm as "heavy, hard, very strong and tough, closely grained, and susceptible of receiving a beautiful polish". Historically noted for a variety of uses in woodworking including furniture, heavy agricultural implements, timber frame buildings, pianos, hockey sticks, and hand tools. U. thomasii is extremely drought tolerant, adaptable to very calcareous soils, and compared to U. americana or U. rubra has a very conservative growth rate requiring minimal attention in regards to pruning. Rock elm naturally tends to develop into a nice structural specimen in the landscape, unlike other fast growing U. americana cultivars in the nursery trade needing frequent attention. Rock elm has very fissured bark and is well known for maintaining a strong central leader resulting in a very attractive, pyramidal form. Despite many literature sources stating that "wings" on the stems are a key identifiying characteristic, this trait is not reliable and many genotypes may completely lack "wings" on the stems. While growth habit and morphology of dormant buds (very pointy) are good traits to help aid in identification, fruits are the best way to confirm identity. Fruits are densly pubescent, often described as "inflated" and generally reach maturity a couple weeks after U. rubra and U. americana. U. thomasii inflorescences are rather distinguishable from other Ulmus in being pendulous. Fruits are extremely prized treats for many birds, where fruits are often "robbed" prior to full maturity. Fruits are also highly prized by many other animals such as mice, squirrels, chipmunks, turkeys, etc. and are generally consumed within hours after fruit abscission. The native range of U. thomasii is concentrated in the northeastern United States and into Canada with disjunct populations documented in northwestern Missouri and northwestern Arkansas (Little, E. L. Jr. 1971). In the 1895 Silva of North America (vol. 7) it was stated that, “The value of the wood of the Rock Elm threatens its extinction and most of the large trees have already been cut.” Today, since rock elm is rather rare, especially in areas near the edges of its range, many states list the species as endangered or threatened warranting preservation efforts. This accession was collected in northeast Nebraska (Dixon County) at Ponca State Park representing genetics from the extreme northwestern edge of the species native range and includes genetics (#775-6) from the current (2022) state champion. In an assessment of seedlings from all mother trees sampled (Carstens, J., personal communication, 12 April 2022), #775-4 produces the most vigorous seedlings which also consistently exhibited extremely corky/winged stems on new seedlings. Seedlings from other maternal lines show both winged and non-winged seedlings within the same maternal line and seedlings from some maternal lines have no wings. | 1649925 | Ames 27341 |
| 13 | Ames 2945 | 'K-2' | Maclura pomifera (Raf.) C. K. Schneid. | Kansas, United States | NC7 | | Not Available | 1984 | COLLECTED | 02/08/1978 | Collected in the vicinity of highway 81 including Sumner, Sedgwick and Harvey Counties. | 37.81221100, -97.33505900 | | Roadside. | Clone | The native range for Osage-orange is reported from eastern Texas, southeastern Oklahoma, southwestern Arkansas, and the northwestern corner of Louisiana (Little, 1971). Historically and presently known for its extreme value as bow-wood and fence posts, Osage-orange represents one of the most widely planted tree species in the lower 48 US states as a living fence starting in the mid-1800's, in the late 1900's as a landscape tree for difficult sites, and most recently it's chemical properties. Detailed history of Osage-orange and it's economic uses are well documented (Smith and Perino, 1981 and J. T. Winberry 1979). Osage wood is highly-prized for its use as fence posts (both living and non-living) and durable wood for wood working. Osage is an extremely drought and heat tolerant tree and is recommended for use in USDA cold-hardiness zones 5b or warmer. Although the species is commonly known for it's stout thorns and large, globular fruits, the species is dioecious and the degree of thorns on individual genotypes can be extremely variable. In the 1970's Al Ferguson (Iowa Arboretum) and John Pair (Kansas State University) evaluated select clones, typically thornless, male selections that were acquired across portions of the Midwest. This accession represents the clonal selection K-2. Based on notes by Ferguson, a total of "6 or 7 clones were collected in Kansas with three clones K-1, K-2, and K-3 selected for further evaluation" due to vigor and "relatively thornless" and "all male". A letter from Al Ferguson to John Pair in 1978, indicated "K-2 was the strongest grower" (comparison against K-1, K-2, and K-3). The first specimen of K-2 donated to NCRPIS was in 1984 by Al Ferguson. In 2006, the specimen was coppiced near the soil level to generate better wood for cutting collection. In 2024, this specimen was noted producing fruit (female) and thornless. Whether this 1984 specimen was incorrectly identified as male by Ferguson is one possibility, but other issues (e.g. propagation via rootstock suckers rather than K-2 scion; labeling mix-up; resprouting of rootstock following coppicing; etc.) may exist. In 2012, Andy Schmitz (Brenton Arboretum) propagated off the 1984 NCRPIS specimen via cuttings which resulted in propagules that formed numerous thorns. Later in 2020 and 2024, propagation by A. Schmitz was executed off a K-2 specimen located at the John C. Pair Horticultural Center, which did not develop thorns and specimens were subsequently donated to NCRPIS. Currently the 1984, 2020, and 2024 specimens are under further evaluation at NCRPIS. | 1022650 | Ames 2945 |
| 14 | Ames 2946 | 'K-3' | Maclura pomifera (Raf.) C. K. Schneid. | Kansas, United States | NC7 | | Not Available | 1984 | COLLECTED | 02/08/1978 | Collected in the vicinity of highway 81 including Sumner, Sedgwick and Harvey Counties. | 37.47818300, -97.33344000 | | Roadside. | Clone | The native range for Osage-orange is reported from eastern Texas, southeastern Oklahoma, southwestern Arkansas, and the northwestern corner of Louisiana (Little, 1971). Historically and presently known for its extreme value as bow-wood and fence posts, Osage-orange represents one of the most widely planted tree species in the lower 48 US states as a living fence starting in the mid-1800's, in the late 1900's as a landscape tree for difficult sites, and most recently it's chemical properties. Detailed history of Osage-orange and it's economic uses are well documented (Smith and Perino, 1981 and J. T. Winberry 1979). Osage wood is highly-prized for its use as fence posts (both living and non-living) and durable wood for wood working. Osage is an extremely drought and heat tolerant tree and is recommended for use in USDA cold-hardiness zones 5b or warmer. Although the species is commonly known for it's stout thorns and large, globular fruits, the species is dioecious and the degree of thorns on individual genotypes can be extremely variable. In the 1970's Al Ferguson (Iowa Arboretum) and John Pair (Kansas State University) evaluated select clones, typically thornless, male selections that were acquired across portions of the Midwest. Based on notes by Ferguson, a total of "6 or 7 clones were collected in Kansas with three clones K-1, K-2, and K-3 selected for further evaluation" due to vigor and "relatively thornless" and "all male". A letter from Al Ferguson to John Pair in 1978, indicated "K-2 was the strongest grower" (comparison against K-1, K-2, and K-3). This accession represents the selection K-3, a clonal, thornless male. | 1022651 | Ames 2946 |
| 15 | Ames 2947 | 'Keokuk' | Maclura pomifera (Raf.) C. K. Schneid. | Iowa, United States | NC7 | | | 1984 | COLLECTED | NEAR 1980 | Along Highway 21, north of What Cheer, northwest corner of Keokuk County. | 41.46821400, -92.35496300 | | Roadside hedgerow. | Cultivar | The native range for Osage-orange is reported from eastern Texas, southeastern Oklahoma, southwestern Arkansas, and the northwestern corner of Louisiana (Little, 1971). Historically and presently known for its extreme value as bow-wood and fence posts, Osage-orange represents one of the most widely planted tree species in the lower 48 US states as a living fence starting in the mid-1800's, in the late 1900's as a landscape tree for difficult sites, and most recently it's chemical properties. Detailed history of Osage-orange and it's economic uses are well documented (Smith and Perino, 1981 and J. T. Winberry 1979). Osage wood is highly-prized for its use as fence posts (both living and non-living) and durable wood for wood working. Osage is an extremely drought and heat tolerant tree and is recommended for use in USDA cold-hardiness zones 5b or warmer. Although the species is commonly known for it's stout thorns and large, globular fruits, the species is dioecious and the degree of thorns on individual genotypes can be extremely variable. In the 1970's Al Ferguson (Iowa Arboretum) and John Pair (Kansas State University) evaluated select clones, typically thornless, male selections that were acquired across portions of the Midwest. Based on notes by Ferguson, a total of "5 clones were collected along highway 21 north of What Cheer in Keokuk County Iowa with two clones named Keokuk and What Cheer selected for further evaluation" due to vigor and "relatively thornless" and "all male". This accession represents the selection Keokuk, a clonal, thornless male. | 1022658 | Ames 2947 |
| 16 | Ames 2948 | 'What Cheer' | Maclura pomifera (Raf.) C. K. Schneid. | Iowa, United States | NC7 | | Not Available | 1984 | COLLECTED | NEAR 1980 | Along Highway 21, north of What Cheer, northwest corner of Keokuk County. | 41.43194600, -92.35583400 | | Roadside hedgerow. | Clone | The native range for Osage-orange is reported from eastern Texas, southeastern Oklahoma, southwestern Arkansas, and the northwestern corner of Louisiana (Little, 1971). Historically and presently known for its extreme value as bow-wood and fence posts, Osage-orange represents one of the most widely planted tree species in the lower 48 US states as a living fence starting in the mid-1800's, in the late 1900's as a landscape tree for difficult sites, and most recently it's chemical properties. Detailed history of Osage-orange and it's economic uses are well documented (Smith and Perino, 1981 and J. T. Winberry 1979). Osage wood is highly-prized for its use as fence posts (both living and non-living) and durable wood for wood working. Osage is an extremely drought and heat tolerant tree and is recommended for use in USDA cold-hardiness zones 5b or warmer. Although the species is commonly known for it's stout thorns and large, globular fruits, the species is dioecious and the degree of thorns on individual genotypes can be extremely variable. In the 1970's Al Ferguson (Iowa Arboretum) and John Pair (Kansas State University) evaluated select clones, typically thornless, male selections that were acquired across portions of the Midwest. Based on notes by Ferguson, a total of "5 clones were collected along highway 21 north of What Cheer in Keokuk County Iowa with two clones named Keokuk and What Cheer selected for further evaluation" due to vigor and "relatively thornless" and "all male". This accession represents the selection What Cheer, a clonal, thornless male. | 1022659 | Ames 2948 |