# Why native trees become rare, and ten rare eastern species worth growing

> Why native trees become rare, from ice-age relicts and scarce soils to blight and lost fire, what G-ranks mean, and ten rare eastern trees and shrubs to grow.

Published 2026-09-24. Tags: Forests & habitat, What to plant. By Blue Whale Trees, a native tree nursery in the United States. Web version: https://bluewhaletrees.com/articles/why-native-trees-become-rare/

A native tree becomes rare when the ground or climate it needs survives in only a few places, or when an introduced disease or pest reaches it. It also declines when the fire that kept its habitat open stops or the water it depends on changes, and small, scattered populations add risks of their own. NatureServe ranks three of the ten eastern species below as globally vulnerable: Georgia oak, seaside alder and Ashe's magnolia. Six more rank as secure or apparently secure worldwide but are patchy, local or imperiled at the edges of their ranges. Chestnut blight has cut back the tenth, Ozark chinquapin.

![A white Ashe's magnolia flower opening among broad, pale green leaves, with trees behind](https://bluewhaletrees.com/img/articles/why-native-trees-become-rare-1-1000.jpg?v=dcc79be9 "Ashe's magnolia in flower in northwest Florida on May 25, 2006. It grows wild only on the Florida panhandle, where NatureServe counts 60 to 70 known sites.")
*Photo: EvaK, [CC BY-SA 2.5](https://creativecommons.org/licenses/by-sa/2.5) ([source](https://commons.wikimedia.org/wiki/File%3AMagnolia_ashei_blossom.jpg))*

## Relicts left behind by the ice ages

Some rare trees are relicts, populations left behind when a species' range shrank. A disjunct population is one cut off from the rest of its species by a wide gap. Seaside alder is both. It grows at the edges of ponds and small streams, often standing in water.

Seaside alder's stands lie in three areas hundreds of miles apart: Delaware and adjacent Maryland, southern Oklahoma, and one area of Georgia. Flora of North America, which lists only the Delaware, Maryland and Oklahoma stands, reads them as remnants of ranges held during and after the ice ages:

> "The populations probably represent remnants of Pleistocene and post-Pleistocene distributions and migrations." (Flora of North America, *Alnus maritima*)

The three groups are treated as subspecies. Georgia alder, known from a single area, is ranked critically imperiled, and Oklahoma alder grows in only two counties of that state. Most seaside alder sites lie along one river, the Nanticoke in Delaware and Maryland.

[Oglethorpe oak](https://bluewhaletrees.com/plants/oglethorpe-oak/index.html.md), which we grow, may be another relict. It grows in western South Carolina and the adjacent part of Georgia, with outlying populations in Alabama, Mississippi and Louisiana. Wilbur Duncan, who found it in 1940, suggested that so scattered a range may mark an old species now reduced to relic populations. Stands this far apart do not fit the single outline of a [range map](https://bluewhaletrees.com/articles/range-maps-are-wrong/index.html.md), and the maps often drop them.

## Soils and rock found in only a few places

### Granite outcrops

Georgia oak grows on granite outcrops and on dry slopes over granite. It is most abundant in Georgia, where it occurs in about 14 counties, and rare in Alabama. The only South Carolina record is historical. Some of its outcrops draw hikers and cars, and that foot and vehicle traffic leads to compacted soil, erosion and possibly fewer seedlings.

### Bluffs, ravines and lime

Ashe's magnolia is endemic to the Florida panhandle, between the Ochlockonee River and Santa Rosa County. It grows in rich hardwood forest on ravine slopes, bluffs and narrow creek floodplains. It favors the upper parts of steep ravines headed by springs. An [understory](https://bluewhaletrees.com/articles/glossary/index.html.md) tree that needs a closed canopy, it suffers when logging opens the canopy or eroding soil washes into its ravines.

Silky camellia grows on similar ground from Virginia to Texas: shaded bluffs, ravine slopes and upper floodplain terraces that seldom flood. Chalk maple, another understory tree, grows in moist, rocky soils on river banks, ravines and cliffs from North Carolina to Texas.

![A white five-petaled silky camellia flower with a ring of purple stamens among green leaves](https://bluewhaletrees.com/img/articles/why-native-trees-become-rare-2-1000.jpg?v=2ef6e70a "Silky camellia in flower in the Ethel Stratton Vance Natural Area near Liberty, Mississippi, on May 5, 2003. NatureServe counts more than 70 sites for it in that state.")
*Photo: Mac H. Alford, [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0) ([source](https://commons.wikimedia.org/wiki/File%3AStewartia_malacodendron_1130.jpg))*

Nutmeg hickory grows on river bottomlands, stream edges and bluffs, often over calcareous soils. It is the rarest hickory, patchy from the coastal plain of North Carolina to the mountains of northeastern Mexico. [American smoketree](https://bluewhaletrees.com/plants/american-smoketree/index.html.md) grows on limestone outcrops from Alabama and Tennessee west to central Texas.

### River swamps

Ogeechee tupelo grows along rivers, swamps and ponds that flood often. Its range runs from coastal South Carolina to the Florida panhandle. It is plentiful along the Ogeechee, Altamaha and Suwannee rivers, yet it makes up less than 1 percent of the woody plants in its Florida range. The limit is plain:

> "Ogeechee tupelo is limited to alluvial soils along the rivers and in river swamps." (USDA Forest Service, *Ogeechee Tupelo*)

It grows on soils that stay flooded for long periods, but only where the water moves at least a little. It is ranked critically imperiled in South Carolina, at the northern end of its range.

## Diseases and pests from abroad

[Introduced pests and diseases](https://bluewhaletrees.com/articles/beech-leaf-disease/index.html.md) stand apart from every other cause:

> "Nonnative forest pests are the only disturbance agent that has effectively eliminated entire tree species or genera from United States forests within decades." (Lovett and others, *Nonnative forest insects and pathogens in the United States: impacts and policy options*, 2016)

The pests come in by two main routes: imported live plants, and wood packing such as pallets and crates. [Chestnut blight](https://bluewhaletrees.com/articles/chinese-chestnut/index.html.md) came in on live plants and effectively eliminated the American chestnut, once a dominant tree, from eastern forests early in the 20th century.

The same blight attacks the chinquapins. It has wiped Ozark chinquapin out of most of Alabama and is blamed for severe losses in the Ozarks. The species now grows mainly in the Ozark highlands of Arkansas, Missouri and Oklahoma. A Forest Service guide to rare plants of the Ozark Plateau listed it as endangered in Missouri in 1978 because of the blight.

![Ozark chinquapin branch with long, bristle-toothed leaves and pale, fuzzy flower catkins](https://bluewhaletrees.com/img/articles/why-native-trees-become-rare-3-1000.jpg?v=4dacba9c "Ozark chinquapin in flower on Mount Magazine in Logan County, Arkansas, on June 5, 2016. Chestnut blight has wiped it out of most of Alabama and cut its numbers in the Ozarks.")
*Photo: Eric Hunt, [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0) ([source](https://commons.wikimedia.org/wiki/File%3ACastanea_ozarkensis.jpg))*

Oglethorpe oak may be at risk from the blight as well. A 1979 report judged its young and old trees quite susceptible, and the idea still needs study.

Laurel wilt, a disease spread by the redbay ambrosia beetle and its fungus, arrived in wood packing. It is predicted to cause a loss of more than 90 percent of redbay basal area, the combined cross-section of its trunks, within 15 years. Its probable hosts include pondberry and pondspice, and pondberry is listed as endangered under the federal Endangered Species Act. The emerald ash borer, also carried in wood packing, attacks every North American ash. Most ash trees it reaches die, though some ash species appear to have limited resistance.

## Lost fire, changed water and closing shade

[Allegheny chinquapin](https://bluewhaletrees.com/plants/allegheny-chinquapin/index.html.md), which we grow, shows what lost fire does. It is not very shade tolerant, and more shade-tolerant trees replace it once a canopy closes over it. Fire helps it by clearing those competitors and opening the overstory, and it sprouts back vigorously after a fire kills its top.

In Appalachian Kentucky it is known from fewer than 10 records, and the botanists who listed it as rare there suspected fire suppression and chestnut blight. It also turns up where people keep the ground open: railroad rights-of-way, power-line clearings, fence rows and [old fields](https://bluewhaletrees.com/articles/old-field-succession/index.html.md).

Changes in water work the same way on wet ground. Seaside alder is resilient in its habitat but vulnerable to succession if that habitat changes. The Clarks Hill dam on the Savannah River may have drowned some Oglethorpe oak sites, and beaver dams could flood its stands beside small streams.

Not every rare tree wants fire back. Fire is probably not a normal part of Oglethorpe oak's moist habitat and would likely kill its seedlings. Clearing for farms probably did that oak the most harm before 1940, and it survived along roadsides and old fence rows.

## Small populations and how rarity is ranked

NatureServe ranks each species worldwide on a scale from G1 to G5. Each state's natural heritage program ranks it for that state on the same scale, from S1 to S5. The global ranks read this way:

- **G1, critically imperiled:** at very high risk of extinction.
- **G2, imperiled:** at high risk of extinction.
- **G3, vulnerable:** at moderate risk, from a fairly restricted range, relatively few populations, recent declines or threats.
- **G4, apparently secure:** at fairly low risk, with some cause for concern.
- **G5, secure:** at very low risk.

A question mark marks an inexact rank, and GNR means a species has not yet been ranked, as with Ozark chinquapin. A tree can be secure overall and critically imperiled at its edge. Chalk maple is G5 but S1 in Mississippi. Two-wing silverbell is G5 as well, but SH, possibly extirpated, in Arkansas.

A rank is not a law. Ranks and the official lists of endangered and threatened species use different criteria and do not necessarily coincide. None of the ten species here is listed under the federal Endangered Species Act. Land protection varies: almost three quarters of known Ashe's magnolia sites are under [conservation ownership](https://bluewhaletrees.com/articles/protecting-forestland-for-good/index.html.md) or management, against a dozen or fewer for seaside alder.

Small populations carry risks that large ones absorb. Ashe's magnolia has 60 to 70 known sites, few with more than 100 plants, and the whole species likely numbers a few thousand. At about a third of those sites it was last seen before 1988. Crossing with other red oaks is a concern for the small stands of Georgia oak, and its one North Carolina stand is believed to be hybrid. For Oglethorpe oak, acorn eaters that a large population would absorb could severely affect a small one.

Some rarity is simply poorly known. Among the oaks of the Southeast, bluff oak is probably the most misunderstood. It is fairly widespread but apparently abundant only in local areas, poorly represented in herbaria and often mistaken for other oaks.

## The ten species at a glance

The table sets out where each species grows wild, why it is scarce and its global rank. S1 means critically imperiled in that state, S2 imperiled and SH known there only from historical records.

| Species | Where it grows wild | Why it is scarce | Global rank |
|---|---|---|---|
| [Georgia oak](https://bluewhaletrees.com/plants/georgia-oak/index.html.md) | Granite outcrops in Georgia and Alabama | Rare outside Georgia, trail traffic, crossing with other red oaks | G3 |
| [Seaside alder](https://bluewhaletrees.com/plants/seaside-alder/index.html.md) | Pond and stream edges in Delaware, Maryland, Oklahoma and Georgia | Relict stands far apart, draining, damming | G3 |
| [Ashe's magnolia](https://bluewhaletrees.com/plants/ashe-magnolia/index.html.md) | Ravine slopes and bluffs of the Florida panhandle | One small range, logging, erosion | G3 |
| [Ozark chinquapin](https://bluewhaletrees.com/plants/ozark-chinquapin/index.html.md) | Dry uplands, cliff margins and rocky ridges of the Ozarks | Chestnut blight, S2 in Missouri and Oklahoma | Not ranked |
| [Nutmeg hickory](https://bluewhaletrees.com/plants/nutmeg-hickory/index.html.md) | Bottomlands, stream edges and bluffs from North Carolina to Texas and Mexico | Patchy everywhere, S1 in North Carolina, Georgia and Oklahoma | G4 |
| [Bluff oak](https://bluewhaletrees.com/plants/bluff-oak/index.html.md) | River bottoms, wet forests and flatwoods from North Carolina to Florida and Arkansas | Abundant only locally, S1 in North Carolina and Arkansas | G4? |
| [Silky camellia](https://bluewhaletrees.com/plants/silky-camellia/index.html.md) | Shaded bluffs, ravine slopes and floodplain terraces from Virginia to Texas | Rare at its edges, S1 in Texas and Arkansas | G4 |
| [Ogeechee tupelo](https://bluewhaletrees.com/plants/ogeechee-tupelo/index.html.md) | River swamps from coastal South Carolina to the Florida panhandle | Needs wet soil with moving water, S1 in South Carolina | G4G5 |
| [Chalk maple](https://bluewhaletrees.com/plants/chalk-maple/index.html.md) | Moist, rocky river banks, ravines and cliffs from North Carolina to Texas | Land conversion, S1 in Mississippi | G5 |
| [Two-wing silverbell](https://bluewhaletrees.com/plants/two-wing-silverbell/index.html.md) | Floodplains, ravines, swamps and hammocks from South Carolina to Texas | Rare only at its edge, SH in Arkansas | G5 |

## What a planter can do

Grow rare species from seed. Every tree Blue Whale Trees sells is grown from seed rather than grafted, so each seedling is genetically distinct, and each of the ten species above now has a page of its own. None of the ten can be ordered today, and our [rare and uncommon oaks](https://bluewhaletrees.com/shop/rare-oaks/index.html.md) are the part of the catalog closest to this list.

Botanic gardens and seed banks keep conservation collections of rare species, held off site to support their survival in the wild. A collection may be seeds, tissue or whole plants. Such a collection should record where each seed came from and which mother plant bore it. It should hold seed or plants from at least 50 unrelated mothers in each population, from several populations across the range. A tree in a yard is not a conservation collection unless its provenance is on record, so [ask where the seed came from](https://bluewhaletrees.com/articles/seed-source-and-provenance/index.html.md).

Leave wild stands alone unless you have permission. Collecting seed takes the landowner's consent, and a listed species may also need permits from state and federal agencies. Those permits can take six months to a year. Even then, the rule for rare plants is to take no more than 10 percent of a population's seed in a season and to leave only footprints.

## Common questions

### What does G3 mean for a plant?

It means NatureServe ranks the species vulnerable worldwide, at moderate risk of extinction.

### What is the rarest hickory?

Nutmeg hickory is the rarest species in the genus. It grows in scattered spots from North Carolina to northeastern Mexico.

### Is it legal to collect seed from a rare tree?

Only with the landowner's permission, and a listed species may also need permits from state and federal agencies. Even then, the rule is to take no more than 10 percent of a population's seed in a season.

### Are rare trees protected by law?

Not because of their rank, since ranks do not necessarily coincide with the official endangered and threatened lists. None of the ten species here is listed under the federal Endangered Species Act.

## Sources

- [Magnolia ashei, Ashe's Magnolia](https://explorer.natureserve.org/Taxon/ELEMENT_GLOBAL.2.132306/Magnolia_ashei): NatureServe Explorer: the G3 rank, 60 to 70 known sites, a third of them last surveyed before 1988, and almost three quarters under protection; the other nine species' ranks, ranges and threats are on their own Explorer pages.
- [Conservation Status Assessment](https://www.natureserve.org/conservation-status-assessment): NatureServe: what the G1 to G5 and S1 to S5 ranks mean, and that a rank implies no legal status or action.
- [Alnus maritima](http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=233500036): Flora of North America: seaside alder's habitat, and its widely separated populations as probable remnants of the ice ages.
- [Quercus austrina](http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=233501010): Flora of North America: bluff oak's habitat and range, and why it is poorly known and often misidentified.
- [Carya myristiciformis](http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=233500319): Flora of North America: nutmeg hickory's habitats on calcareous soils, its patchy range and its standing as the rarest hickory.
- [Halesia diptera](http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=250092277): Flora of North America: the habitats and states of two-wing silverbell.
- [Ogeechee Tupelo](https://research.fs.usda.gov/silvics/ogeechee-tupelo): USDA Forest Service, Silvics of North America: the river-swamp soils Ogeechee tupelo is limited to, its need for moving water, its range and its scarcity in Florida.
- [Castanea pumila](https://www.fs.usda.gov/database/feis/plants/tree/caspum/all.html): USDA Forest Service, Fire Effects Information System: chestnut blight's toll on Ozark chinquapin, its habitat in the Ozark highlands, and how shade and fire decide where chinquapin grows.
- [Acer leucoderme, chalk maple](https://plants.ces.ncsu.edu/plants/acer-leucoderme/): NC State Extension Gardener Plant Toolbox: the habitat and range of chalk maple.
- [Nonnative forest insects and pathogens in the United States](https://research.fs.usda.gov/treesearch/50937): Lovett and others, Ecological Applications 26 (2016): pests that eliminate tree species, how they arrive, and chestnut blight, laurel wilt and the emerald ash borer.
- [Collecting Rare Plant Seeds](https://saveplants.org/best-practices/collecting-seeds-wild-rare-plant-populations/): Center for Plant Conservation: what a conservation collection should hold, the permission and permits collecting needs, and the 10 percent limit on seed taken in a season.