13 Delightful Viburnums for Your Erie County, PA Butterfly Garden

There are 13 species of native or nearly native Erie County, PA viburnums (Viburnum spp.) that can be grown for butterflies and other insects. Viburnums are an important host species for three butterflies, the Henry’s elfin, spring azure, and the Baltimore checkerspot in Erie County. These plants are also an important nectar source to all insects visiting your pollinator garden and a food source for birds.

General Information about Native Plant and Pollinator Gardens

When planting a native plant and pollinator garden in Erie County, Pennsylvania, you need to ensure that you have a selection of plants that provide blooms at different times of the year. Besides viburnums, other host plants that attract other butterflies and pollinators should be considered. These could include milkweeds (Asclepias spp.) for monarch (Danaus plexippus) and queen (Danaus gilippus) butterflies, spicebush (Lindera benzoin) for the spicebush swallowtail (Papilio troilus), pawpaw (Asimina triloba) for zebra swallowtails (Eurytides marcellus), pipevine (Aristolochia spp.) for pipevine swallowtails (Battus philenor), and passionflower (Passiflora incarnata) for the Gulf fritillary (Agraulis vanillae).

In addition to the plants, you need to provide a source of water such as a birdbath or water feature, shelter for animals, and nesting locations for birds. Be sure to also include plants of different heights for perching. Resources you can use for more information on butterfly gardening in Erie County, PA include The Penn State Master Gardeners of Erie County, Asbury Woods Nature Center, the Tom Ridge Environmental Center, and the Lake Erie Arboretum.

Location of Erie County, PA

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Erie County, Pennsylvania is located in the northwestern part of the state, south of Lake Erie. The major municipalities in Erie County are the City of Erie and Millcreek Township.

USDA Plant Hardiness Zones in Erie County, PA

Erie County, Pennsylvania has two plant hardiness zones within it. Adjacent to Lake Erie and about two miles going inland (south) is Zone 7a. This area, which includes Presque Isle, has temperatures that are moderated by the lake. Going south to about I-90 is zone 6b and roughly south of I-90 is zone 6a. When selecting plants north of I-90, generally the City of Erie, you will want to get those that can handle temperature as cold as -5⁰F. South of of I-90you will want to get those that can handle temperatures as cold as -10⁰F.

Butterflies in Erie County, PA that are Hosted by Viburnums (Viburnum spp.)

Spring Azure (Celastrina ladon)

The Spring Azure is a silvery metallic blue on the upperside and has a silvery underside. Females, unlike the males, have a black margin on the wings. A fully grown adult has a wingspan of 0.87 in (2.2 cm) and 1.38 in (3.5 cm).

The whitish eggs are laid on the flower buds of host plants. Several broods a year, more in the south and less in the north, can produce green colored larvae with brown accents. Note, this species may be in Erie County and is present to the west in Ohio.

Baltimore Checkerspot (Euphydryas phaeton)

The Baltimore Checkerspot is a speckled white, orange, and black butterfly. This butterfly is found in the eastern United States and southern Canada from the mid-west and east. Adults have a wingspan of 1.6 in (4.1 cm) to 2.5 in (6.4 cm).

The eggs of this species are yellow and become a reddish-tan color with age (wildadirondacks.org). The caterpillars are black with orange stripes (Pyle 1981). There is one brood that flies from May to July. This butterfly is so named because the color resembles the crest of Lord Baltimore (Pyle 1981).

List of Viburnums that are Native or Nearly Native in Erie County, Pennsylvania

1. Maple-leaf Viburnum (Viburnum acerifolium), a Viburnum for Dry to Moist Well-drained Soils

Maple-leaf viburnum is found rich forests, woodlands, and woodland thickets in dry to moist well-drained soils that are slightly acidic. The plants should get about 4-6 hours of direct sunlight each day. During dry spells, the plants shoud be watered and a layer of mulch should be laid to help suppress weeds. Suitable companion plants for this species in Erie County include New England aster (Symphyotrichum novae-angliae), goldenrods (Solidago spp.), butterfly weed (Asclepias tuberosa), purple coneflower (Echinacea purpurea), black-eyed susan (Rudbeckia hirta), wild parsnip (Pastinaca sativa), spicebush (Lindera benzoin), and pawpaw (Asimina triloba).

Facts about Maple-leaf Viburnum

• Native to Pennsylvania: Yes, throughout (Kartesz 2015)
• Native to Erie County: Yes
• Natural Habitat: Rich forests, woodlands, and woodland thickets that have medium to dry soils.
• Height: 3 ft (0.9 m) to 6 ft (1.8 m)
• Flower Color: cream to white
• Flowering Period: June
• USDA Hardiness Zone: 3-8

Gardening with Maple-leaf Viburnum

In your Erie County, Pennsylvania butterfly garden this species requires part-shade or dappled sunlight and dry to moist soils that are well-drained. This plant can handle full sun conditions in a garden setting, but does best in shaded conditions.

Learn More about Maple-leaf Viburnum

2. Bracted Viburnum (Viburnum bracteatum), a Viburnum for Medium to Moist Well-drained Soils

Bracted viburnum, in the wild, is found in open wooded areas where it can get full sun to part shade conditions. It prefers medium to moist well-soils that are slightly acidic. To feature this plant in your garden, plant it in the center with the companion plants surrounding it. When selecting companions try to get plants that match the white flowers of the viburnum, for instance, flowering dogwood (Cornus florida). Some other possible plants to choose are similar to those of the maple-leaf viburnum, with the addition of joe-pye weed (Eutrochium purpureum) and ironweed (Vernonia noveboracensis) to match the height of this shrub. For shadier areas, consider coral bells (Heuchera spp.), foamflower (Tiarella cordifolia), wild ginger (Asarum canadense), and ferns.

Be sure to have a variety of nectar plants that bloom throughout the season in order to provide sustenance to butterflies and other insects. One great choice in the fall is goldenrod (Solidago spp.), which provides a wealth of nectar in the late season.

Facts about Bracted Viburnum

• Native to Pennsylvania: No (Kartesz 2015)
• Native to Erie County: No
• Natural Habitat: open wooded areas
• Height: 6 ft (1.8 m) to 10 ft (3.0 m)
• Flower Color: cream to white
• Flowering Period: May to June
• USDA Hardiness Zone: 6-8

Gardening with Bracted Viburnum

In your Erie County, Pennsylvania butterfly garden this viburnum requires full sun to part-shade medium to moist soils that are well-drained. This plant is known for its fragrance. In the southern parts of Erie County, this plant is close to its cold tolerance, but in time with climate change warming will likely do better here.

3. Southern Arrow-wood (Viburnum dentatum), a Viburnum for Medium to Moist Well-drained Soils

Southern arrow-wood is so named for the straight stems that used to be made into arrows by the Native Americans. This shrub can reach a height of 15 feet and has white flowers. Soils should be medium to moist and well-drained with a full sun to part shade exposure. In the fall the blue berries are enjoyed by birds. Suitable companion plants in sunnier places include those previously mentioned plus coral honeysuckle (Lonicera sempervirens), switchgrass (Panicum virgatum), beebalm (Monarda didyma), and blazing star (Liatris spicata). For shadier places, oak-leaf hydrangea (Hydrangea quercifolia), wild columbine (Aquilegia canadensis), woodland phlox (Phlox divaricata), and cinnamon fern (Osmundastrum cinnamomeum).

Facts about Southern Arrow-wood

Viburnum dentatum var. dentatum in Pennsylvania

• Native to Pennsylvania: Yes, southeastern counties (Kartesz 2015)
• Native to Erie County: No
• Natural Habitat: Rich forests, woodlands, floodplains, and wetlands
• Height: 5 ft (1.5 m) to 15 ft (4.6 m)
• Flower Color: cream to white
• Flowering Period: March to June
• USDA Hardiness Zone: 2-8

Gardening with Southern Arrow-wood

In your Erie County, Pennsylvania butterfly garden, this species requires full sun to part-shade and medium to moist well-drained soils. In a garden situation, it can handle drier soils (Flemer 1984). This shrub has brilliant color in the fall, which gives added value to your garden.

Learn More about Southern Arrow-wood

4. Hobblebush (Viburnum lantanoides), a Viburnum for Moist to Wet Well-drained Soils

Hobblebush is so named for the straight stems that used to be made into arrows by the Native Americans. This shrub can reach a height of 15 feet and has white flowers. Soils should be medium to moist and well-drained with a full sun to part shade exposure. In the fall the blue berries are enjoyed by birds. Suitable companion plants in sunnier places include those previously mentioned plus coral honeysuckle (Lonicera sempervirens), switchgrass (Panicum virgatum), beebalm (Monarda didyma), wild bergamot (Monarda fistulosa), and blazing star (Liatris spicata). For shadier places, oak-leaf hydrangea (Hydrangea quercifolia), wild columbine (Aquilegia canadensis), woodland phlox (Phlox divaricata), and cinnamon fern (Osmundastrum cinnamomeum).

Facts about Hobblebush

• Native to Pennsylvania: Yes, northern counties and Laurel Mountains (Kartesz 2015)
• Native to Erie County: Yes
• Natural Habitat: Rich woods that are moist, stream banks, and swamps
• Height: 3 ft (1.0 m) to 10 ft (3.0 m)
• Flower Color: white to pink
• Flowering Period: May to June
• USDA Hardiness Zone: 3-6

Gardening with Hobblebush

In your Erie County, Pennsylvania butterfly garden, this species requires part shade and moist to wet well-drained soils.

Learn More about Hobblebush

5. Nanny-Berry (Viburnum lentago), a Viburnum for Medium to Moist Well-drained Soils

Nanny-Berry in the wild grows wooded wet areas and grows from 15 to 18 feet tall. In a garden situation it requires medium to moist soils and full sun to part shade. Companion plants should be chosen to provide a color tapestry and enhance the feeding opportunities provided by this shrub.

Suitable plants to include with nanny-berry to ensure a maximum diversity of butterflies include asters such as New England aster (Symphyotrichum novae-angliae), smooth aster (Symphyotrichum laeve), aromatic aster (Symphyotrichum oblongifolium), goldenrods such as showy goldenrod (Solidago speciosa) and wrinkle-leaf goldenrod (Solidago rugosa), milkweeds such as butterfly weed (Asclepias tuberosa), common milkweed (Asclepias syriaca), and swamp milkweed (Asclepias incarnata). Nectar plants such as purple coneflower (Echinacea purpurea) and mountain mints (Pycnanthemum spp.) can also be included.

Facts about Nanny-Berry

• Native to Pennsylvania: Yes, generally throughout, except for south-central counties (Kartesz 2015)
• Native to Erie County: Yes
• Natural Habitat: Rich woods that are moist, stream banks (King 1912), swamps, roadsides (Arnold Arboretum 1919), wood edges (Mohlenbrock 1954), thickets (McCormac and Schneider 1994)
• Height: 15 ft (4.5 m) to 18 ft (5.5 m)
• Flower Color: cream to white
• Flowering Period: May to June
• USDA Hardiness Zone: 2-8

Gardening with Nanny-Berry

In your Erie County, Pennsylvania butterfly garden, this viburnum requires full sun to part-shade and medium to moist well-drained soils.

Learn More about Nanny-Berry

6. Soft-leaf Arrow-wood (Viburnum molle), a Viburnum for Moist to Dry Well-drained high-pH Soils

Soft-leaf arrow-wood, in the wild, grows on rocky bluffs and bottomlands. It can get a height of 6-12 feet high and white blossoms in the spring with blue drupes in the autumns, which are loved by birds. Suitable companion plants in the Erie County area include those mentioned above with the other viburnums plus mountain mint (Pycnanthemum tenuifolium), alum-root (Heuchera spp.), little bluestem (Schizachyrium scoparium), Virginia bluebell (Mertensia virginica), and woodland phlox (Phlox divaricata). A planting of redbud (Cercis canadensis) can provide some color interest in the spring.

Facts about Soft-leaf Arrow-wood

• Native to Pennsylvania: No (Kartesz 2015)
• Native to Erie County: No
• Natural Habitat: Rocky bluff forests on calcareous substrate and bottomlands (wikipedia).
• Height: 6 ft (1.8 m) to 12 ft (3.7 m)
• Flower Color: cream to white
• Flowering Period: May to June
• USDA Hardiness Zone: 2-8

Gardening with Soft-leaf Arrow-wood

In your Erie County, Pennsylvania butterfly garden, this viburnum requires full sun to part-shade and moist to dry well-drained high pH soils. However, it may be hard to find since it is rare throughout most of its range.

7. Possumhaw (Viburnum nudum), a Viburnum for Medium to Wet Well-drained Soils

Possumhaw, in the wild, grows in wetland areas and reaches a height of up to 15 feet. The snowball shaped white flowers come out in May and it has a blue-black drupe in the fall that is enjoyed by birds. The leaves also have an attractive red color in the fall. Suitable companion plants in the Erie County area are different than some of the other species because of needing moist to wet soils.

For sunnier places, swamp milkweed (Asclepias incarnata), Joe-Pye weed (Eutrochium purpureum), cardinal flower (Lobelia cardinalis), and ironweed (Vernonia noveboracensis) are suitable. For shadier places, winterberry (Ilex verticillata), buttonbush (Cephalanthus occidentalis), cinnamon fern (Osmundastrum cinnamomeum), and Pennsylvania sedge (Carex pensylvanica) are great companions.

Because of the soils, river birch (Betula nigra) and black gum (Nyssa sylvatica), can make for some taller companions in the garden.

Facts about Possumhaw

Viburnum nudum var. cassinoides and Viburnum nudum var. nudum in Pennsylvania

• Native to Pennsylvania: Yes, var. cassinoides generally throughout, var. nudum, rare in southeastern counties (Kartesz 2015)
• Native to Erie County: Yes, var. cassinoides
• Natural Habitat: Swamps (wikipedia), seepage swamps (Belden and Derge 2003 and Sundell, et al 1999), and bogs (MacRoberts, et al 2004)
• Height: 5 ft (1.5 m) to 15 ft (4.6 m)
• Flower Color: white to cream
• Flowering Period: April to June
• USDA Hardiness Zone: 5-9

Gardening with Possumhaw

In your Erie County Pennsylvania butterfly garden, this species requires full sun to partial shade and medium to wet well-drained soils. This species may be a good long-term choice, given climate change warming.

Learn More about Possumhaw

8. Small-leaf Arrow-wood (Viburnum obovatum), a Viburnum for Medium Well-drained Soils

Small-leaf arrow-wood grows in mesic woodlands and in a garden setting with ideal conditions can reach a height of 30 feet. However, generally it is shorter in most cases. Like a number of other viburnums, it has white flowers and blue-black drupes that are eatern by birds. Possible companion plants to plant with this viburnum in Erie County include butterfly weed (Asclepias tuberosa), black-eyed susan (Rudbeckia hirta), purple coneflower (Echinacea purpurea), joe-pye weed (Eutrochium purpureum), and blazing star (Liatris spicata).

Facts about Small-leaf Arrow-wood

• Native to Pennsylvania: No (Kartesz 2015)
• Native to Erie County: No
• Natural Habitat: disturbed mesic woodlands (Anderson 2007)
• Height: 10 ft (3.0 m) to 30 ft (9.1 m)
• Flower Color: white
• Flowering Period: March to April
• USDA Hardiness Zone: 6-10

Gardening with Small-leaf Arrow-wood

In your Erie County, Pennsylvania butterfly garden, this viburnum requires full sun to partial shade and medium well-drained soils. This species is native to the southeastern United States and can handle warmer temperatures. This would be a good long term choice in light of climate change induced warming for the area, especially near to the lake.

Learn More about Small-leaf Viburnum

9. Highbush Cranberry (Viburnum opulus), a Viburnum for Medium to Moist Well-drained Soils

Highbush Cranberry is a small to medium sized shrub that grows in medium to moist soils. When planting this shrub, be sure you get var. americanum, which is the native variety. This variety has stalked petiolar glands, while the European variety, var. opulus, has sessile petiolar glands. Some suitable companion plants for this species are swamp milkweed (Asclepias incarnata), common milkweed (Asclepias syriaca), columbine (Aquilegia canandensis), goldenrod (Solidago spp.), and asters (Symphyotrichum spp.).

Facts about Highbush Cranberry

Viburnum opulus var. americanum: Native and rare Pennsylvania

• Native to Pennsylvania: Yes, rare and scattered throughout (var. americanum) (Kartesz 2015)
• Native to Erie County: Yes
• Natural Habitat: lowland woods (Macdonald 2003), moist woods (Bird 1961), rivershores and banks (Hosie 1938), shrub swamps (Thomson 1944), gravelly calcareous places, (Wiegand and Eames 1926), swamps and rarely dry woods (McVaugh 1958), and roadsides and field edges (Go Botany)
• Height: 8 ft (2.4 m) to 16 ft (4.9 m)
• Flower Color: yellow to white
• Flowering Period: April to June
• USDA Hardiness Zone: 2-7

Gardening with Highbush Cranberry

In your Erie County, Pennsylvania butterfly garden, this viburnum requires full sun to partial shade and medium to moist well-drained soils. This species is the at the upper limit of its hardiness zone in Erie County, especially near the lake, and could experience heat stress in the future. This species has two varieties, has two varieties, one of which, var. opulus, is exotic to North America. Variety americanum is native to North America.

Learn More about Highbush Cranberry

10. Smooth Blackhaw (Viburnum prunifolium), a Viburnum for All Soils

Smooth blackhaw is generally found in disturbed habitats and like the small-leaf viburnum can greatly exceed the height its wild counterparts in an ideal garden setting, growing up to 30 feet. It also has white flowers and reddish-purple drupe in the fall that is loved by birds. Companion plants that provide a good color contrast include butterfly weed (Asclepias tuberosa), black-eyed susan (Rudbeckia hirta), and joe-pye weed (Eutrochium fistulosum). Since this species can handle a wide variety of soils, other companion plants are similar to the other species, althoough you may want to plant more trees or shrubs to match the height of the species.

Facts about Smooth Blackhaw

• Native to Pennsylvania: Yes, generally throughout, except for northern counties (Kartesz 2015)
• Native to Erie County: No, but is just west in Ohio
• Natural Habitat: Open areas, upland woods, floodplains (Gaddy 2008), disturbed habitats (Clark and Bauer 2001), thickets (Fernald 1936)
• Height: 7 ft (2.1 m) to 30 ft (9.1 m)
• Flower Color: White
• Flowering Period: May to June
• USDA Hardiness Zone: 3-9

Gardening with Smooth Blackhaw

In your Erie County, Pennsylvania butterfly garden, this viburnum needs full sun to part-shade and dry to moist well-drained soils. This species can handle warmer hardiness zones than present in Erie County, making it a good long-term choice.

Learn More about Smooth Blackhaw

11. Downy Arrow-wood (Viburnum rafinesquianum), a Viburnum for Dry Well-drained Soils

Downy arrow-wood is found in woodland areas in the wild and is noted for its fall foliage, which is a bronze-purple color. Growing up to 10 feet tall it has white to cream flowers and a blue-black drupe, loved by birds. Possible companion plants in the Erie County area include New York Ironweed (Vernonia noveboracensis), blazing star (Liatris spicata), swamp milkweed (Asclepias incarnata), obedient plant (Physostegia virgniana), and columbine (Aquilegia canadensis).

Facts about Downy Arrow-wood

• Native to Pennsylvania: Yes, throughout, but scattered (Kartesz 2015)
• Native to Erie County: No, but is native in adjacent county
• Natural Habitat: open woodlands, rocky hillside (Reaume 2009), rocky shorelines (Rousseau 1974), limestone savanna (Alvar) (Catling and Brownell 1995), dry thickets (Maycock and Eahselt (1997), and low woodlands (Fernald 1942)
• Height: 6 ft (1.8 m) to 10 ft (3 m)
• Flower Color: white to cream
• Flowering Period: May to June
• USDA Hardiness Zone: 3-8

Gardening with Downy Arrow-wood

In your Erie County, Pennsylvania butterfly garden, this viburnum needs full sun to part shade and dry well-drained soils. This species is noted for its bronze-purple foliage in the fall (Koller 1981).

Learn More about Downy Arrow-wood

12. Smooth Arrow-wood (Viburnum recognitum), a Viburnum for Medium to Moist Well-drained Soils

Smooth arrow-wood can found in wetland areas and woodlands in the wild. Growing up to 15 feet tall, this species has white flowers and drupes that are loved by birds in the fall. Suitable companion plants include blazing star (Liatris spicata), butterfly weed (Asclepias tuberosa), cardinal flower (Lobelia cardinalis), and spotted Joe-Pye weed (Eutrochium maculatum).

Facts about Smooth Arrow-wood

• Native to Pennsylvania: Yes (Kartesz 2015)
• Native to Erie County: Yes
• Natural Habitat: swamps (Dugal 1988), damp thickets (Roedner, et al 1978), thickets (Palmer 1974), secondary dunes and seasonal ponds (Lortie, et al 1991), and mesic woodland forest (Larimore, et al 2008)
• Height: 5 ft (1.5 m) to 15 ft (4.6 m)
• Flower Color: white or rarely pink (Roedner, et al 1978)
• Flowering Period: March to June
• USDA Hardiness Zone: 4-9

Gardening with Smooth Arrow-wood

In your Erie County, Pennsylvania butterfly garden, this viburnum needs full sun to part shade and moist to medium well-drained soils. This species can exist in a higher hardiness zone than is present in Erie County, making it a good long-term choice.

Learn More about Smooth Arrow-wood

13. Rusty Blackhaw (Viburnum rufidulum), a Viburnum for Medium to Dry Soils

Rusty blackhaw is generally found in drier woodlands in the wild. Growing up to 20 feet tall, it has white flowers and blue-black drupes in the autumn. Companion plants that complement rusty blackhaw include butterfly weed (Asclepias tuberosa), black-eyed susan (Rudbeckia hirta), sweet Joe-Pye weed (Eutrochium purpureum), and purple coneflower (Echinacea purpurea).

Facts about Rusty Blackhaw

• Native to Pennsylvania: No (Kartesz 2015)
• Native to Erie County: No
• Natural Habitat: rocky or dry woods (Steyermark 1940), limestone (Thompson, et al 2005), cedar barrens (Carr 1944), oak-hickory woodlands (Wofford, et al 1979), calcareous prairies (MacRoberts and MacRoberts 1996), and disturbed habitats (Clark and Bauer 2001)
• Height: 10 ft (3.0 m) to 20 ft (6.1 m)
• Flower Color: white to cream
• Flowering Period: April to May
• USDA Hardiness Zone: 5-9

Gardening with Rusty Blackhaw

In your Erie County, Pennsylvania butterfly garden, this viburnum needs full sun to part shade and dry to medium well-drained soils. This plant can handle poor soils making it versatile for most garden situations.

Learn More about Rusty Blackhaw

When selecting your Erie County, PA viburnum, be sure to make sure that it grows in your zone and habitat.

Books where you can find out more about Butterfly Gardening in Erie County, PA

• Clausen, Ruth Rogers, and Gregory D. Tepper. 2021. Deer-Resistant Native Plants for the Northeast. Little and Brown 208 pp.
• Daniels, Jaret C. 2024. Caterpillars of North America: Easily Identify 90 Common Butterflies and Moths – Adventure Quick Guides. Adventure Publications. 36 pp.
• Daniels, Jaret C. 2022. Garden Bugs & Insects of the Northeast: Identify Pollinators, Pests, and Other Garden Visitors. Adventure Quick Guides.
• Daniels, Jaret C. 2019. Butterflies of the Northeast: Identify Butterflies with Ease. Adventure Publications.
• Lorimer, Uli. 2022. The Northeast Native Plant Primer: 235 Plants for an Earth-Friendly Garden. Little and Brown Publishers. 250 pp.
• Mehl, Geoffrey L. 2016. Pennsylvania Naturally – A Gardener’s Guide to Sustainable Landscaping. Pennystone Books. 396 pp.
• Mehl, Geoffrey L. 2012. Pennsylvania Native Plants/Perennials – Habitat and Culture. Pennystone Books. 202 pp.
• Monroe, James L. and David M. Wright. 2017. Butterflies of Pennsylvania. (Pittsburgh, PA: University of Pittsburgh Press). 304 pp.

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References for Erie County, PA Viburnums

• Arnold Arboretum. 1919. Viburnum lentago. Bulletin of Popular Information. 5 (7): 28.
• Belden, Allen and Katherine L. Derge. 2003. The flora and fauna of Virginia Army National Guard OMS No. 1 and No. 2 near Sandston, Henrico County, Virginia. Banisteria 22: 22-42.
• Bird, Ralph Durham. 1961. Ecology of the aspen parkland of western Canada in relation to land use. (Ottawa: Canada Department of Agriculture).
• Bouchard, Andre’, Denis Barabe’, Madeliene Dumais, and Stuart Hay. 1983. The Rare Vascular Plants of Quebec. (Ottawa, ON: National Museum of Natural Sciences).
• Catling, Paul M. and Vivian R. Brownell. 1995. A review of the Great Lakes Region: Distribution, floristic comparison, biogeography, and protection. The Canadian Field-Naturalist 109 (2): 143-171.
• Carr, Lloyd G. 1944. A New Species of Houstonia from the Cedar Barrens of Lee County, Virginia. Rhodora 46: 306-310.
• Clark, Ross C. and Ryan M. Bauer. 2001. Woody Plants of Six Northern Kentucky Counties. Journal of the Kentucky Academy of Science 62(1): 39-51.
• Dugal, Albert W. 1988. Southern Arrow-wood, Viburnum recognitum, A Rare Ontario Species in the Ottawa District. Trail & Landscape 22 (4): 151-155.
• Fernald, Merritt Lyndon. 1942. The Seventh Century of additions to the flora of Virginia. Rhodora 44: 457-479.
• Fernald, Merritt Lyndon. 1936. Plants from the Outer Coastal Plain of Virginia (continued). Rhodora 38: 414-452.
• Gaddy, L.L. 2008. A New Sessile-Flowered Trillium (Liliaceae: Subgenus Phyllantherum) from South Carolina. Phytologia 90 (3): 382-390.
• Hosie, R.C. 1938. Botanical Investigations in Batchawana Bay Region, Lake Superior. National Museum of Canada: Bulletin 88.
• Kartesz, J.T. The Biota of North America Program (BONAP). 2015. Taxonomic Data Center (BONAP). Chapel Hill, N.C. [maps generated from Kartesz, J.T. 2015. Floristic Synthesis of North America, Version 1.0. Biota of North America Program (BONAP). (in press)].
• King, Wilbur. 1912. The Flora of Northampton County, Pennsylvania. Torreya 12: 208-215.
• Koller, Gary. 1981. Shrubs for Hillsides and Embankments. Arnoldia 41: 193.
• Larrimore, Richard L., Loy R. Phillippe, and John E. Ebinger. 2008. Vascular Flora of Middle Fork Woods Nature Preserve, Vermillion County, Illinois. Illinois Natural History Survey Bulletin 38, article 4.
• Lortie, J.P., Bruce A. Sorrie, D.W. Holt. 1991. Flora of the Montgomery Islands Chatham, Massachusetts. Rhodora 93: 361-389.
• Macdonald, Ian D. 2003. A rare plant survey of the Wainwright Dunes Ecological Reserve. (Edmonton, Alberta: Alberta Sustainable Resource Development).
• MacRoberts, Michael H., Barbara R. MacRoberts, and Lynn Stacey Johnson. 2004. Observations of Parnassia grandifolia DC. (Saxifragaceae) in the West Gulf Coast Plain. Phytologia 86: 98-103.
• MacRoberts, Barbara R. and Michael H. MacRoberts. 1996. The floristics of calcareous prairies on the Kisatchie National Forest, Louisiana. Phytologia 81: 35-43.
• Maycock, Paul F. and Dianne Eahselt. 1997. An inventory of ecologically significant natural vegetation in the province of Ontario: 1. Essex County. The Canadian Field-Naturalist 101: 474-486.
• McCormac, J.S. and G.J. Schneider. 1994. Floristic Diversity of a Disturbed Western Ohio Fen. Rhodora 96: 327-353.
• McVaugh, Rogers. 1958. Flora of the Columbia County area, New York. (Albany, NY: University of the State of New York).
• Mohlenbrock, R.H. 1954. Some notes on the flora of Southern Illinois. Rhodora 56: 227-228.
• Palmer, Ernest J. 1947. Second supplement to the spontaneous Flora of the Arnold Arboretum. Journal of the Arnold Arboretum 28: 410-418.
• Reaume, Tom. 2009. Biology of the Downy Arrow-wood (Viburnum rafinesquianum). Blue Jay 67 (2): 89-96.
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