Vascular Plants of North Carolina
Account for Maryland Butterfly-pea - Clitoria mariana   L.
Members of Fabaceae:
Only member of Clitoria in NC.
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Section 6 » Order Fabales » Family Fabaceae
DistributionEssentially statewide, but perhaps absent in a few northern Mountain counties and a few northeastern counties.

This is primarily a Southern species, ranging north to NJ, southeastern PA, and MO, and then south to the Gulf Coast from FL to TX.
AbundanceCommon nearly statewide, but rare in the northern Mountains, and uncommon in the northeastern Coastal Plain.
HabitatThis is a species of usually dry to fairly dry and rather sunny habitats. It grows best along margins of upland woods and similar roadbanks, but it is also widespread in open pine stands in the Sandhills, in upland thickets, old fields, and other upland and sunny places.
PhenologyBlooms from June to August, and fruits from July to October.
IdentificationThis species is quite similar to Centrosema virginianum in many respects. Clitoria is a slender herbaceous vine, usually trailing on the ground but at times climbing weakly onto other plants, and reaching 3-4 feet long. It has scattered alternate leaves, each with 3 leaflets that are ovate in shape and about 1.5-2 inches long and half as wide. The undersides of the leaflets do not show leaf venations, as opposed to those in Centrosema, which do show a strong leaflet venation pattern below. The flowers are somewhat similar, but in Clitoria the standard portion of the flower is curled upward into a partial tube, resembling a spoon in shape, whereas Centrosema has a rotund and flat standard. Clitoria's standard is about 2 inches long, lavender in color, with a dark purple center; Centrosema's standard is about 1.5 inches long and often wider, is a fairly rich purple or blue-purple in color, and has a white center. The wings and keel (the other parts of the petals) are also quite different between the two, though this is hardly needed to identify the flowers. People spending much time in the field, especially walking along wooded margins and wide trails through upland woods, should fairly quickly become familiar with both Clitoria and Centrosema, though the latter is hard to find in most of the mountains and far eastern counties. Both have among the largest single flowers in the pea/legume family (Fabaceae) and are easily spotted at some distance.
Taxonomic CommentsAs this species has a fairly large range, including into South America, there are several varieties of the species. The one over most of the US, including NC, is the nominate Clitoria mariana var. mariana.

Other Common Name(s)Most references still use "Butterfly-pea" for the common name of this species. However, Centrosema virginianum is widely named as Spurred Butterfly-pea, and thus the words "Butterfly-pea" are a nested name that should be discouraged, and strongly suggests a modifier name for Clitoria. A few, including NatureServe, use Maryland Butterfly-pea, as the scientific epithet of "mariana" refers to Maryland. The use of Atlantic Pigeonwings by several references does solve the nested problem, but that is an idiosyncratic name and does not seem to be in normal or popular usage. This website will use Maryland Butterfly-pea, for the reasons indicated above -- it is not confusing, and it is not an odd name.
State RankS5
Global RankG5
State Status
US Status
USACE-agcpFACU link
USACE-empFACU link
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B.A. SorrieCamp Mackall, clearing on W side of US 15-501. 5 June 2010. ScotlandPhoto_natural
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