Proceedings of the South Dakota Academy of Science, Vol. 87 (2008) 197 A RANGE EXTENSION FOR CYPRIPEDIUM MON- TANUM DOUGLAS EX LINDLEY (ORCHIDACEAE) INTO THE BLACK HILLS OF SOUTH DAKOTA Mark Gabel and Dan Tackett Herbarium Department of Biology Black Hills State University Spearfish, SD 57799 ABSTRACT Cypripedium montanum has previously been known from the northwestern states of the U.S. and from southern Alberta and British Columbia. A recent discovery of white-flowered lady s slipper orchids has extended the range of plants into the Black Hills of South Dakota. To verify the identification of the plants, living specimens of related C. parviflorum in the Black Hills were measured, as were specimens of C. montanum from the Big Horn Mountains. Cluster analysis and principal component analysis grouped the white-lipped plants from the Black Hills with C. montanum from the Big Horn Mountains. This is the first report of C. montanum in South Dakota and the easternmost report of the species in North America. Keywords Cypripedium, orchid, Black Hills, South Dakota, flora INTRODUCTION The orchid family (Orchidaceae) has long fascinated amateur and professional botanists with beautiful and highly specialized flower structure. The family is one of the largest plant groups in the world with about 22,000 to 35,000 species (Flora of North America Editorial Committee 2002). Most of the species are tropical to subtropical, with only about 208 species occurring in North America (Flora of North America Editorial Committee 2002). Within the Great Plains, 15 genera and 37 species of orchids have been reported (Great Plains Flora Association 1986). Kravig (1969) described 16 species of orchids in the Black Hills, and Van Bruggen (1996) noted 22 species of orchids in South Dakota, with 17 occurring in the Black Hills. The genus Cypripedium is represented in North America by 12 species (Sheviak 2002). Van Bruggen (1966) reported two members of the genus in South Dakota, C. candidum in the east, and C. parviflorum (= C. calceolus) in the Black Hills and in the northeast.
198 Proceedings of the South Dakota Academy of Science, Vol. 87 (2008) Vance (2007) has noted that in U. S. Forest Service Region 2, C. montanum is present on the eastern flank of the Big Horn Mountains in Johnson and Sheridan Counties, Wyoming, with six occurrences comprising less than 2500 individuals. Hybrids of C. montanum and C. parviflorum have not been reported from Wyoming. One cluster of orchid stems, clearly belonging in the genus Cypripedium, was discovered by one of the authors (DT) on privately owned land in the northern Black Hills of South Dakota. It is the purpose of this study to determine and report the correct identification of the unknown plants. MATERIALS AND METHODS Site Characteristics Black Hills The white-lipped plants of unknown species were discovered on a northeast facing slope in Lawrence County, South Dakota, near Hanna Campground at N44º 16.9 and W103º 52.1 and about 1700 m in elevation. The plants were growing with Picea glauca, Aralia nudicaulis, Actaea rubra, Viola sp., Rosa sp., Spiraea betulifolia and Cornus canadensis. At the site, which is very similar in plant species composition to other north facing slopes in the northern Black Hills, were no indications of human disturbance and no exotic ornamental plants. A voucher specimen has been deposited at the Black Hills State University Herbarium. Plants of a known population of C. parviflorum were measured at a site approximately 1 air km from the site of the unknown Cypripedium species at W44º 16.3 and N103º 51.5. The 11 plants measured were scattered over about 200 m along a trail margin. Big Horns The plants measured were found in Sheridan County, Wyoming, near South Piney Creek (N44º 38.48, W106º 56.02 ) growing at an elevation of about 1675 m. Plants associated with the orchids included Pinus ponderosa, Acer glabrum, Populus tremuloides and Spiraea betulifolia. The 12 plants measured were scattered over about 400 m along a trail. Plants in this study were all living specimens measured at flowering time. Plant Measurements Fifteen characteristics were measured on plants that appeared to be in good condition (Table 1) including plant height, number of leaves, length and width of largest leaf blade, dorsal sepal color, dorsal sepal length and width, lower sepal(s) length and width (lower sepals are fused), petal color, petal length and width, lip color, lip length and orifice length. Statistical analyses of plant measurements were accomplished with cluster analysis and principal component analysis (PCA) using NTSYSpc 2.2 (Rohlf 2005).
Proceedings of the South Dakota Academy of Science, Vol. 87 (2008) 199 RESULTS The white-lipped plants observed in the Black Hills produced only two flowers in 2007. Measurements are shown in Table 1. Cluster analysis grouped the unknown plants with C. montanum. The broad differences between the two major groups (Figure 1) clearly indicate that the unknown plants are not C. parviflorum PCA produced a very robust model (in 15 dimensional space) accounting for 89.8% of the variation in the system in the first three dimensions (Figure 2). The PCA clearly grouped the unknown plants with C. montanum. The great divergences between the specimens of C. parviflorum from the Black Hills and the similarities between the known C. montanum and the newly discovered specimens in the Black Hills can lead only to the conclusion that the Black Hills white-lipped plants are C. montanum. Figure 1. Cluster analysis of unknown (Uk) species occurring in the Black Hills of South Dakota, Cypripedium montanum (Cm) measured from the Big Horn Mountains of Wyoming, and Cypripedium parviflorum (Cp) from the Black Hills of South Dakota.
200 Proceedings of the South Dakota Academy of Science, Vol. 87 (2008) Figure 2. Principal component analysis of unknown (Uk) species occurring in the Black Hills of South Dakota, Cypripedium montanum (Cm) measured from the Big Horn Mountains of Wyoming, and Cypripedium parviflorum (Cp) from the Black Hills of South Dakota. DISCUSSION Cribb (1997) noted that C. montanum is unlikely to be confused with other American species apart from C. candidum. Cypripedium candidum has been reported from eastern South Dakota (Van Bruggen 1996) and has a white lip. We did not include C. candidum in the detailed analyses since it can be separated from both C. parviflorum and C. montanum by several characteristics. These include: flowers that unfold usually before the leaves unwrap from about the stem (Luer 1975), shorter stature, leaves narrow and suberect, usually only 3-4 leaves present, sepal color, shorter petals, and occurrence below 1000 m (Cribb 1997, Sheviak 2002). Three varieties of C. parviflorum (= C. calceolus) have been described (Sheviak 2002). Van Bruggen (1996) reported two of these varieties from South Dakota (C. parviflorum var. parviflorum and C. parviflorum var. pubescens). C. parviflorum Salisbury var. pubescens (Willd.) O. W. Knight occurs in western South Dakota (Sheviak 2002). Sheviak (2002) noted that in C. parviflorum lip color is very rarely white thus, we considered the possibility that the white-lipped Black Hills species could be a light variant of C. parviflorum. Cluster analysis and PCA were run without the characteristic of lip color to determine if that single character could influence the distribution of the individuals in the models. Both analyses indicated essentially no difference in the distribution of the individuals. The cluster
Proceedings of the South Dakota Academy of Science, Vol. 87 (2008) 201 Table 1. Measurements taken from living plant specimens. Uk = Unknown species occurring in the Black Hills; Cm = Cypripedium montanum from Wyoming; Cp = Cypripedium parviflorum from the Black Hills; Plant Ht = plant height (cm); Leaf No = leaf number per stem; Bld L = Leaf blade length (mm), Bld W = Leaf blade width (mm), DsepCol = dorsal sepal color 1 = maroon-brown, 0 = other; DsepL = dorsal sepal length (mm); DsepW = dorsal sepal width (mm); LsepL = lower (connate) sepal pair length (mm); LsepW = lower (connate) sepal width (mm); PetCol = petal color, 1 = maroon-brown, 0 = other; PetL = petal length (mm); PetW = petal width (mm); LipCol = lip color, 1 = white, 0 = yellow; LipL = lip length (mm); OrifL = orifice length (mm). Specimen Plant Ht Leaf No Bld L Bld W DsepCol DsepL DsepW LsepL LsepW PetCol PetL PetW LipCol LipL OrifL Uk1 32 6 89 40.3 1 38 9 32 8 1 41 4 1 21 12 Uk2 32 6 89 40.3 1 45 10 39 9 1 55 4 1 22 12 Cm1 39 8 112 68 1 46 10 42 13 1 51 5 1 21 11 Cm2 38 7 112 68 1 45 10 33 11 1 48 5 1 20 10 Cm3 39 6 128 55 1 46 9 41 10 1 48 4 1 21 10 Cm4 39 6 116 51 1 45 12 39 12 1 54 4 1 20 10 Cm5 40 7 101 50 1 40 7 39 8 1 46 5 1 20 10 Cm6 40 7 106 52 1 41 9 39 10 1 46 5 1 21 11 Cm7 46 7 155 65 1 46 7 42 10 1 56 4 1 22 11 Cm8 46 7 149 67 1 39 9 46 9 1 55 5 1 22 11 Cm9 42 7 135 52 1 36 11 34 11 1 41 5 1 20 11 Cm10 42 7 146 60 1 38 11 39 12 1 44 5 1 21 12 Cm11 46 7 155 64 1 36 11 37 13 1 45 5 1 21 10 Cm12 46 7 162 62 1 45 12 44 14 1 45 5 1 22 12 Cp1 26 5 125 45 0 29 13 25 12 0 40 5 0 26 9 Cp2 27 5 140 50 0 32 11 26 9 0 41 5 0 25 10 Cp3 22 4 96 35 0 28 9 21 9 0 38 3 0 26 11 Cp4 19 4 72 25 0 24 10 18 9 0 34 3 0 25 11 Cp5 22 5 109 30 0 29 7 20 11 0 36 4 0 26 16 Cp6 28 4 121 35 0 32 9 25 10 0 42 4 0 24 9 Cp7 25 5 108 36 0 22 8 23 9 0 36 4 0 25 10 Cp8 23 4 94 34 0 30 6 25 8 0 38 4 0 26 10 Cp9 26 4 118 43 0 30 7 32 8 0 44 4 0 26 11 Cp10 19 4 102 35 0 29 12 23 9 0 36 5 0 27 10 Cp11 23 4 100 35 0 31 11 23 11 0 36 5 0 25 10
202 Proceedings of the South Dakota Academy of Science, Vol. 87 (2008) analysis maintained the joining link of the C. montanum and the C. parviflorum clusters at a coefficient of 1.7. PCA maintained the species separation and the relative positions of the individuals in the model. The first three dimensions of the principal component analysis were reduced only from 89.8% to 89.2% by excluding lip color from the analysis. Management considerations include a limited number of available pollinator species, the small seed size and requirements of the plant to grow with a fungal symbiont, and the fact that populations are often small and scattered (Vance 2007). The NatureServe Global rank for C. montanum is G4, but the Wyoming status is S1 (critically imperiled), and it is on the Region 2 USFS sensitive species list. Populations of Cypripedium montanum have decreased throughout their range by 50 to 75% due to fire suppression and logging activities (Vrilakas 2002). The genetic diversity of some Cypripedium species has been studied (Case 1994), but the diversity present in and among populations of C. montanum has not. This report describes the first occurrence of C. montanum in South Dakota and the easternmost extension of the range for this species in North America. We believe that it is important to determine if other populations are present in the state, to inform the botanical community of the presence of the species in the Black Hills, and to protect this beautiful resource for future generations. ACKNOWLEDGEMENTS The authors wish to thank R. Hartman and the staff of the Rocky Mountain Herbarium at the University of Wyoming for access to locality data from the collection. We also thank A. Gabel, G. Kostel, G. Larson and D. Ode for critical reading of the manuscript and valuable suggestions. LITERATURE CITED Case, M.A. 1994. Extensive variation in the levels of genetic diversity and degree of relatedness among five species of Cypripedium (Orchidaceae). American Journal of Botany 81:175-184. Cribb, P. 1997. The genus Cypripedium. Botanical Magazine Monograph, Timber Press, Portland. 358 pp. Flora of North American Editorial Committee. 2002. Flora of North America North of Mexico vol. 26. Oxford University Press, New York. 723 pp. Great Plains Flora Association. 1986. Flora of the Great Plains. University of Kansas Press, Lawrence. 1402 pp. Kravig, M.L. 1969. Orchids of the Black Hills. Proceedings of the South Dakota Academy of Sciences 48:119-131. Luer, C. 1975. The Native Orchids of the United States and Canada. New York Botanical Garden, New York. 361 pp. Rohlf, F.J. 2005. NTSYSpc: numerical taxonomy and multivariate analysis system 2.2. Exeter Software, Setauket, NY.
Proceedings of the South Dakota Academy of Science, Vol. 87 (2008) 203 Sheviak, C.J. 2002. Cypripedium pp. 499-506 in Flora of North American Editorial Committee, Flora of North America North of Mexico, vol. 26. Oxford University Press, New York. Van Bruggen, T. 1996. Vascular Plants of South Dakota. (3rd ed.) University of South Dakota, Vermillion. 293 pp. Vance, N.C. 2007. Cypripedium montanum Douglas ex Lindley (mountain lady s slipper): A technical assessment. U.S.D.A. Forest Service, Rocky Mountain Region. (http://www.fs.fed.us/r2/projects/scp/assessments/cypripediummontanum.pdf). Vrilakas, S. 2002. Heritage rank status factors (pdf). http://www.oregonstate. edu/ornhic/survey/cypripedium_montanum_global.pdf.