Synonym(s): Asarum lewisii
Image ID: 94276
Image by: Fleming, Gary P.
Image Collection: NCBG Digital Library
PLANT INDEX
ID_PLANT: HELE2
SCIENTIFIC NAME: Hexastylis lewisii
Include in WOTAS: 0
Publish to Web: 1
Last Modified: 2019-03-18
GENUS INDEX
GENUS CODE: HEXAS GENUS SCIENTIFIC:Hexastylis GENUS AUTHORITY: Raf. GENUS COMMON: Heartleaf GENUS SUMMARY: A genus of about 11 species, herbs, of se. North America, very possibly best expanded to include Asian taxa treated in Heterotropa and Asiasarum. Barringer (1993) and Kelly (1997, 1998) have recently employed a broad definition of Asarum, including Hexastylis. Over the last half-century various students of the group (emphasizing a range of fields of evidence) have arrayed themselves for and against the recognition of Hexastylis as a genus distinct from Asarum. A cladistic analysis (Kelly 1997, 1998) showed distinctive clades which could be interpreted as evidence for the recognition of Hexastylis (including the Asian Heterotropa), though the author preferred to recognize 2 subgenera. I choose here to follow the more traditional (at least in our area) separation of Hexastylis from Asarum, until and unless stronger evidence is presented for their combination. Electrophoretic and morphologic studies currently in progress validate the species / varietal level taxonomy presented, insofar as results are available (Z. Murrell, pers. comm., 2013; R. Wyatt, pers. comm.). A difficult genus, Hexastylis is made more frustrating by the fact that nearly all diagnostic features relate to the shape and size of the fleshy and brittle calyx – characters which are difficult to describe and are largely lost when specimens are pressed. The difficulty of identifying herbarium specimens has sometimes been (apparently) used as a justification for reducing (often drastically, as in Cronquist) the number of taxa recognized. To those familiar with this genus in the field, however, the taxa here recognized form geographically distinctive populations. Size and (to a lesser degree) shape of individual flowers show considerable variation and can be altered by environmental factors; individual flowers or plants can be difficult to identify if taken out of context. Populations, however, are usually readily identifiable. GENUS IDENTIFICATION: Identification notes: The photograph (Figure 1) in Gaddy (1987a) of the flowers of all species other than H. arifolia and H. speciosa is highly recommended as an aid to identification. The calyxtube orifice is measured on the inside – the diameter of the opening. The width of calyx lobes is measured from sinus tip to sinus tip. GENUS REFERENCES: Whittemore & Gaddy in FNA (1997); Gaddy (1987a)=Z; Blomquist (1957)=Y; Barringer (1993)=X; Keener & Davenport (2015)=V; Gaddy (1987b); Gaddy (1986); Gaddy in Wofford (1989); Sugawara (1987); Huber in Kubitzki, Rohwer, & Bittrich (1993). Key adapted from FNA, Gaddy in Wofford (1989), and Gaddy (1987a).
FAMILY INDEX
FAMILY CODE: ARISTO FAMILY SCIENTIFIC:Aristolochiaceae FAMILY AUTHORITY: A. L. de Jussieu 1789 FAMILY COMMON: Birthwort Family FAMILY SUMMARY: A family of about 6-12 genera and 600 species, vines, shrubs, and herbs, of tropical, subtropical, and warm temperate regions. FAMILY REFERENCE: Barringer & Whittemore in FNA (1997); Ohi-Toma et al. (2006); Neinhuis et al. (2005); Huber in Kubitzki, Rohwer, & Bittrich (1993).
FRUITING PERIOD: DISTRIBUTION
HABITAT TYPE: Moist forests
NATIVE RANGE: Virginia & North Carolina HORTICULTURAL
Plant Sale Text: Native to the lower Piedmont and upper coastal plain of North Carolina and Virginia, this species of Hexastylis is unique in that it forms long rhizomatous patches (up to 3 feet in 5 years) as opposed to the clumping form displayed by other species in this genus. The spreading nature of Hexastylis lewisii makes for a great ground cover option in a shady part of the garden. The flower, though hard to see without close inspection, is dark purple, thimble-sized and very hairy!
Bloom Table Text:
NCBG Location:
Cultural Notes:
SOIL MOISTURE:
Dry, Average, Moist/Wet
LIGHT EXPOSURE:
Part Shade, Shade
MINIMUM HARDINESS ZONE: 5a
MAXIMUM HARDINESS ZONE: 9b
GERMINATION CODE:
WILDLIFE VALUE:
DEER RESISTANCE:
High
This information is derived from the 2018 North Carolina Natural Heritage Program List of Rare Plant Species.
WEAKLEY FLORA
SCIENTIFIC NAME: Hexastylis lewisii
COMMON NAME: Lewis's Heartleaf
SYNONYMY: [= FNA, K, RAB, Va, Y, Z; < H. shuttleworthii - C; = Asarum lewisii Fernald - F]
PHENOLOGY: Apr-May.
HABITAT: Upland forests (pine or oak), pocosin ecotones.
COMMENTS: Endemic to the Piedmont of VA and the Piedmont and Coastal Plain of NC.
RANGE MAP: Hexastylis lewisii.png
Key to Map SymbolsABOUT FAMILY (Weakley Flora) Aristolochiaceae A. L. de Jussieu 1789 (Birthwort Family) SUMMARY: A family of about 6-12 genera and 600 species, vines, shrubs, and herbs, of tropical, subtropical, and warm temperate regions. REFERENCE: Barringer & Whittemore in FNA (1997); Ohi-Toma et al. (2006); Neinhuis et al. (2005); Huber in Kubitzki, Rohwer, & Bittrich (1993).ABOUT GENUS (Weakley Flora) Hexastylis Raf. (Heartleaf) SUMMARY: A genus of about 11 species, herbs, of se. North America, very possibly best expanded to include Asian taxa treated in Heterotropa and Asiasarum. Barringer (1993) and Kelly (1997, 1998) have recently employed a broad definition of Asarum, including Hexastylis. Over the last half-century various students of the group (emphasizing a range of fields of evidence) have arrayed themselves for and against the recognition of Hexastylis as a genus distinct from Asarum. A cladistic analysis (Kelly 1997, 1998) showed distinctive clades which could be interpreted as evidence for the recognition of Hexastylis (including the Asian Heterotropa), though the author preferred to recognize 2 subgenera. I choose here to follow the more traditional (at least in our area) separation of Hexastylis from Asarum, until and unless stronger evidence is presented for their combination. Electrophoretic and morphologic studies currently in progress validate the species / varietal level taxonomy presented, insofar as results are available (Z. Murrell, pers. comm., 2013; R. Wyatt, pers. comm.). A difficult genus, Hexastylis is made more frustrating by the fact that nearly all diagnostic features relate to the shape and size of the fleshy and brittle calyx – characters which are difficult to describe and are largely lost when specimens are pressed. The difficulty of identifying herbarium specimens has sometimes been (apparently) used as a justification for reducing (often drastically, as in Cronquist) the number of taxa recognized. To those familiar with this genus in the field, however, the taxa here recognized form geographically distinctive populations. Size and (to a lesser degree) shape of individual flowers show considerable variation and can be altered by environmental factors; individual flowers or plants can be difficult to identify if taken out of context. Populations, however, are usually readily identifiable. REFERENCE: Whittemore & Gaddy in FNA (1997); Gaddy (1987a)=Z; Blomquist (1957)=Y; Barringer (1993)=X; Keener & Davenport (2015)=V; Gaddy (1987b); Gaddy (1986); Gaddy in Wofford (1989); Sugawara (1987); Huber in Kubitzki, Rohwer, & Bittrich (1993). Key adapted from FNA, Gaddy in Wofford (1989), and Gaddy (1987a).
HERBARIUM RESOURCES
SERNEC: Find Hexastylis lewisii in Southeast Regional Network of Experts and Collections (if available) UNC SERNEC: Find Hexastylis lewisii in
University of North Carolina Chapel Hill Herbarium - Southeast Regional Network of Experts and Collections (if available)