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Bittersweet - Celastrus scandens
State Rank Reason (see State Rank above)
Celastrus scandens is rare in Montana, where plants occur at the western edge of the species' range. Plants are known from at least 4 occurrences in the very eastern portion of the state. Estimates on the size and extent of populations are poorly documented, and trends are unknown. Reported threats include habitat degradation from livestock grazing and competition form non-native plant species; however, data that quantifies these impacts is not available. The combination of rarity in the state and potential on-going threats places Celastrus scandens at high risk of extirpation in the state.
Surveys that bring forth current data on population parameters, habitat conditions, mapping, and potential threats are needed. Monitoring at a subset of occurrences is necessary to track population trends, assess the magnitude of threats, and assign a timely and accurate state conservation status rank. Additional surveys into areas of potential habitat are also important for assessing the species status and distribution in Montana.
Surveys are greatly needed to document population size and extent, habitat quality and threats for all occurrences. Additional surveys of other potentially suitable habitat are also needed to determine if the species may be more abundant than what is currently known.
General Description
Bittersweet is a climbing woody vine with twisting stems that reach up to 18 m long. The alternate, elliptic leaf blades, 5-10 cm long, taper to a pointed tip and have finely serrated edges and petioles reaching up to 3 cm long. The greenish, unisexual flowers are borne in narrow inflorescences which are 3-8 cm long at the end of the stems. The flowers have a cup-shaped calyx which is 2-3 mm high and composed of 5 sepals that are united at the base and of 5 spreading petals that are 3-6 mm long. Male flowers have 5 stamens, while female flowers have a single 3-parted ovary. Fruit is an orange or yellowish capsule, 1 cm in diameter, that splits along three lines to expose the single, large, bright orangish red seed.
Phenology
Flowering and fruiting May-July; fruits persisting in fall.
Diagnostic Characteristics
The combination of alternate leaves, lack of tendrils, and orange fruits with red seeds distinguish this species from all other vines in our area.
Species Range
Montana Range
Range Descriptions
Native
Range Comments
In Richland and Dawson Counties, Montana. Occurs from SK to QC south to WY, TX, TN and NC (Lesica et al. 2012).
Observations in Montana Natural Heritage Program Database
Number of Observations: 16
(Click on the following maps and charts to see full sized version)
Relative Density
Recency
(Observations spanning multiple months or years are excluded from time charts)
Habitat
Riparian woodlands, green ash woodlands, and thickets on the plains.
National Vegetation Classification System Groups Associated with this Species
Forest and Woodland
Deciduous Forest and Woodland
Wetland and Riparian
Riparian and Wetland Forest
Ecology
American bittersweet is sometimes planted as an ornamental because the cluster of red fruits persist until mid-winter (McGregor et al. 1986). In deeply shaded habitats, plants may not produce fruits (McGregor et al. 1986).
Birds often eat the fruit of American Bittersweet, but it may be poisonous to humans and there are reports of horses being poisoned from eating the leaves (McGregor et al. 1986).
Stewardship Responsibility
Threats or Limiting Factors
Reported threats to Montana's populations of Bittersweet are those that negatively impact its woody draw habitat. Plants were observed to have lower vigor where the livestock graze and trample plants in the woody draws. Colonization of woody draws by non-native grasses, Smooth Brome (Bromus inermis) and Kentucky Bluegrass (Poa pratensis) are suspected of impacting Bittersweet’s ability to regenerate and thrive. The use of herbicides to control non-native grasses has the potential to negatively impact Bittersweet. However, the severity and scope of these reported threats has not been quantified.
Climate change poses a potential risk to the state's populations. The MTNHP conducted a species-level assessment using the Climate Change Vulnerability Index (CCVI) in 2021, which resulted in a Moderately Vulnerable rating to climate change. Climate change including increased ambient temperatures, decreased snowpacks, and increased frequencies and severities of drought could have negative impacts on this species; however, field-based data on the timing and magnitude are not available.
References
- Literature Cited AboveLegend:
View Online Publication- Lesica, P., M.T. Lavin, and P.F. Stickney. 2012. Manual of Montana Vascular Plants. Fort Worth, TX: BRIT Press. viii + 771 p.
- McGregor, R.L. (coordinator), T.M. Barkley, R.E. Brooks, and E.K. Schofield (eds). 1986. Flora of the Great Plains: Great Plains Flora Association. Lawrence, KS: Univ. Press Kansas. 1392 pp.
MTNHP Threat Assessment. 2021. State Threat Score Assignment and Assessment of Reported Threats from 2006 to 2021 for State-listed Vascular Plants. Botany Program, Montana Natural Heritage Program, Helena, Montana.
- Additional ReferencesLegend: View Online Publication
Do you know of a citation we're missing?- Lesica, P., M.T. Lavin, and P.F. Stickney. 2022. Manual of Montana Vascular Plants, Second Edition. Fort Worth, TX: BRIT Press. viii + 779 p.
- Web Search Engines for Articles on "Bittersweet"
