Asarum chueyi B.T.Sinn, 2015

Sinn, Brandon T., 2015, Asarum chueyi (Aristolochiaceae), a new species from the foothills of the Blue Ridge Mountains of Tennessee and Virginia, USA, Phytotaxa 224 (1), pp. 85-95 : 92

Asarum chueyi B.T.Sinn , sp. nov. ( Fig. 1 )

Diagnosis— Similar to both A. contractum (Blomquist) Barringer and A. heterophyllum Ashe , though notable for fusiform calyx tube broadest at its midpoint, highly developed reticulations forming irregular pits in the adaxial, proximal portion of the calyx tube, and poorly developed style extensions. Sepal lobes erect to only weakly spreading, as long as or longer than their width at their widest point. Style extensions shorter than the length of the stigmatic surfaces. Stamen filaments cylindrical and tapering distally causing the distal ends of the thecae to be nearer one another than the proximal ends; thecae latrorse or nearly so. Leaves less variegated and more oblong-cordate in shape than those of A. minus .

Type:— UNITED STATES. Virginia: Albemarle County, limestone cliffs along Ravanna River at Route 29. 16 April, 1959. Clyde F. Reed 42803. (Holotype: MO!)

Description:— Perennial herb, clumped growth habit with short rhizome. Petioles glabrous, (8.5–) 9.5–13.5 cm long. Leaf blades minutely revolute, entire, and glabrous, (5.5–) 6.5–8.5 cm long from base of lobe to the apex of the acute leaf tip and (4–) 5.5–8 cm wide, roundly-hastate to oblong-cordate in shape, variegation originating along distal portion of primary veins and quickly fanning broadly along secondary veins; leaf lobes 1.5–2.5 cm long and 2–3 cm wide; Calyx tube 2–2.5 cm long, 0.5 cm wide at the orifice, fusiform and broadest (~ 1 cm) at its mid-point, deep maroon to purple with the exception of pale yellow base, red-villous within, trichomes ending abruptly at the start of the highly reticulate proximal portion of the tube; calyx reticulations composed of strong transverse and longitudinal lines of equal height, the strongest of which are not equal in height to the thickness of the calyx wall, and anastomosing to form deep irregular pits proximally; sepal lobes 1–1.5 cm long, erect to weakly spreading, white mottled, as long or longer than they are broad, with long-tomentose covering of uniformly red trichomes over abaxial surface with the exception of white areas; stamens latrorse to nearly so, thecae 1.5–2 mm long and 0.5 mm wide, filament shorter than the styles, with cylindrical filaments (2.5–3 mm long) tapering and surpassing the thecae by approximately 1 mm, the distal apex of the thecae nearer to one another than the proximal ends; ovary approximately 2/3 superior; styles white mottled with purple at base and gradually becoming entirely purple at the poorly developed, deeply cleft extensions that surpass the ovoid, overhanging stigmas by 1–2 mm; stigmas approximately 1 mm long and 0.5 mm wide. Fruit and seeds not seen.

Phenology:— Flowering mid April–early May, fruiting not observed.

Distribution:— Foothills of the Blue Ridge Mountains in Tennessee and Virginia.

Habitat:— Shaded slopes with exposed rock near streams and rivers.

Associates:— Quercus sp. , Fagus grandifolia , and Kalmia latifolia .

Conservation:— Careful fieldwork is needed to document the occurrence of this taxon to the exclusion of two common species, A. minus and A. heterophyllum , which have been found growing in sympatry. Surveys for additional populations of this taxon should be conducted in order to better assess its distribution.

Etymology:— Named for Carl F. Chuey, a 43-year faculty member of Youngstown State University who botanized extensively throughout the United States, and worked tirelessly to establish a herbarium at his home institution. Perhaps most importantly, he served as a thoughtful and dedicated mentor to many first-generation college graduates, myself included.

Other specimens examined:— USA: Virginia: Albemarle Co., 16 April, 1959, C. F. Reed 42795 (MO) ; Albemarle Co., 27 April , 2013, B. T. Sinn 1148 (OS) ; Albemarle Co., 27 April , 2013, B. T. Sinn 1164 (OS) ; Albemarle Co., 27 April , 2013, B. T. Sinn 1166 (OS) ; Amherst Co., 21 April , 2014, B. T. Sinn 1195 (OS) ; Nelson Co., 19 April 1975, C. F. Reed 99775 (MO) ; Nelson Co., 19 April , 1975, C. F. Reed 99773 (MO) . Tennessee: Greene Co., 20 April, 2014, B. T. Sinn 1190 (OS) .

Figures

FIGURE 1. Example of an A. chueyi (1195) calyx tube silhouette, with the sepal lobes cropped, used for Elliptical Fourier Analysis. The proximal and distal portions of the flower are to the left and right, respectively.