Vascular Plants of North Carolina
Account for Mountain Heartleaf - Hexastylis contracta   Blomquist
Members of Aristolochiaceae:
Members of Hexastylis with account distribution info or public map:
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Section 4 » Order Aristolochiales » Family Aristolochiaceae
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DistributionA limited area in the far western Piedmont and more so in the southern Mountains, generally not far from the Blue Ridge Escarpment. A few disjunct populations in Caldwell County, well to the northeast of other records from Buncombe County south to the SC state line.

This has a small range, being primarily found in the Cumberland Plateau of southeastern KY and east-central TN. There are scattered records east to southwestern VA and western NC.
AbundanceRare, with only about 12 populations known (according to NCNHP records). As there are a decent number of fair, good, or excellent quality occurrences showing in the NHP database, the website editors suggest a slightly less conservative State Rank of S1S2 instead of S1. Even so, it is clearly one of the rarest of NC's Hexastylis species, and owing to its state (and global) rarity it is given a State Endangered protection status.
HabitatThe species is found in a fairly common habitat, but for whatever reason, it is very localized. It grows in cool and heavily shaded, acidic, hardwood forests under or very near Mountain Laurel (Kalmia latifolia) and/or Rosebay Rhododendron (Rhododendron maximum).
PhenologyBlooms in May and June, and fruits shortly after flowering.
IdentificationThis species is quite similar to many others in the genus, and thus biologists must take care in checking the flowers very carefully, as the leaves alone will not suffice. As with most others, it has several broadly rounded, shiny, thick, and evergreen leaves that are about 2.5-3 inches long and across, with a cordate base; they may be unmottled above, or can show some white or pale green veining pattern on the top side of the leaf. The several flowers (calyx only), growing at the base of the leaves in the soil or under fallen leaves, are thick and fleshy, brown, and nearly 1 inch long and half as wide. Each is flask-shaped, widest slightly below the middle, then narrowing somewhat before widening toward the tip, where the three calyx lobes flare out somewhat. The key is that the flask or vase shape is widest just below the middle, pinches in above it but flares out again. The only truly similar calyx belongs to H. rhombiformis, which has a somewhat wider "vase" and not quite as narrow a flower overall. However, the chief separation between these two is that H. contracta has very little ridging inside the tube, whereas H. rhombiformis has noticeable ridges inside the tube. You may have trouble separating these two species, and you may need to cut open a flower to carefully check the ridging pattern.
Taxonomic CommentsNone

Other Common Name(s)None
State RankS1 [S1S2]
Global RankG3
State StatusE
US Status
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