Vascular Plants of North Carolina
Account for Oldfield Milkvine - Matelea decipiens   (Alexander) Woodson
Members of Apocynaceae:
Members of Matelea with account distribution info or public map:
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Section 6 » Order Gentianales » Family Apocynaceae
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Author(Alexander) Woodson
DistributionWeakley (2020) has considered this species to now be present only east to IL and LA westward, and the population east to VA, NC, SC, and GA "appears to represent variability within M. carolinensis". Thus, the account below is for what is now (spring 2021) known as "Matelea decipiens". A recent paper states that this species is restricted to regions west of NC only, leaving the populations in the state "up in the air", most likely just a part of M. carolinensis, but leaving open the possibility of an unnamed species or a distinct taxon within that species. M. decipiens is essentially found only in the Piedmont, where seemingly absent from the northwestern portions. Also a record from the far northern Coastal Plain (Hertford County). No records for the mountains.
AbundanceRare to locally uncommon in the Piedmont, and extremely rare in the northern Coastal Plain. Populations are mostly clustered in the northeastern Piedmont (especially in Granville and Durham counties) and in the southern tier of counties -- from the base of the Blue Ridge Escarpment on the west to Richmond County on the east. Despite records from at least 21 counties, this is considered as a Significantly Rare species by the NCNHP, even though it has an S3 State Rank. It probably could be moved to the Watch List, as it has been recorded from nearly half of the Piedmont counties. NOTE: Owing the the comments in Weakley (2020), the website editors are recommending a State Rank of simply SU (Undetermined).
HabitatThis species is essentially restricted to circumneutral (high pH) soils, but mostly in dry conditions. It occurs in mafic glades and barrens, along the margins and in openings of Basic Oak-Hickory Forests, in powerline clearings, and other partly sunny to mostly sunny places. It can be found in more mesic sites, but the very similar M. carolinensis favors these mesic to rich sites.
See also Habitat Account for Basic Barrens and Glades
PhenologyBlooms from April to June, and fruits from August to October.
IdentificationThis species is an herbaceous vine that climbs over other vegetation to a length of 6' or more. It has scattered opposite leaves that are heart-shaped to widely ovate, like many other vine species. The leaves are about 5" long and 3-4" wide, being pointed at the tip and cordate at the base. The stems and petioles are normally very hairy/hirsute, as often are the leaves, rather than the somewhat glabrous stems, petioles, and leaves as seen in M. carolinensis. In leaf axils grow the flower clusters, usually 10-15 or more flowers in a cluster, as opposed to mainly 5-8 flowers in the other species. The flowers, a maroon-purple in color, normally have strongly ascending petals, and the petals are usually 3-6 times longer than wide, as opposed to shorter petals in M. carolinensis, which has petals mainly just 2-2.5 times as long as wide. All Matelea species have spiny, rough pods and these are not normally useful in separation, as opposed to flower number and shape. Another character used in separation of the two species is that the flowers, when in bud, form a narrow conical shape, as opposed to a shorter and more rounded flower bud in M. carolinensis. The usual habitats of the two typically differ, as M. decipiens is a strong "obligate mafic" species, found only on high pH soils and almost always in dry to xeric conditions, such as glades and barrens, and along margins of dry woods. Unfortunately, plants are seen in mesic habitats that simply are troubling to identify! This species can be found in quite a few natural areas in the Piedmont that protect rare natural communities and rare "prairie plant" species.
Taxonomic CommentsSee Distribution. Many Carolina botanists have noticed that there is indeed variability in this complex -- in dry and often more mafic sites that plants are more hairy and have more flowers than those in more shaded and richer sites, but with a gradation of characters in more mesic and partly shaded places.

Other Common Name(s)Climbing Milkweed, Deceptive Spinypod
State RankS3 [SU]
Global RankG5
State StatusSR-P
US Status
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