Table Of Content

RHODORA, Vol. 103. No. 916. 351-379. 2001 pp. CONSERVATION STATUS OF CAREX ORONENSIS MAINE ENDEMIC (CYPERACEAE), A Alison Dibble and Christopher Campbell C. S. 1 Department of Biological Sciences, 5722 Deering Hall, ME University of Maine, Orono, 04469-5722 Current Address: U.S. Department of Agriculture. Forest Service, Northeastern Research 686 Government Station, Rd., ME Bradley, 0441 I e-mail: [email protected] abstract. Carex oronensis, Orono sedge, Maine's only known endem- is ic plant species. From 1916 through 1986 only one individual was collected. From we 1986 1998, and others found 58 populations and approximately 2862 reproductive individuals in early successional habitats, almost exclu- < Of 80% sively the Penobscot River drainage. extant populations, have in 22% 20 plants, and have only 1-2. In a Principal Coordinates Analysis with 22 morphological variables and 95 individuals, oronensis separated com- C. pletely from C. bebbii, C. ovalis, C. scoparia var. tessellata, and C. tincta. 100% Canonical Discriminant Analysis resulted in classification for 19 individuals of C. oronensis. Carex oronensis differs from the lour other taxa especially perigynium features: narrow wings, lack of abaxial nerves, in glossy texture, rust-colored blotch (OS'r of sample), and lack of basal spong- iness about the achene. Species status appropriate for C. oronensis because is is fertile, its offspring are identical lo the parent, and is morphologically it it distinct. Because distribution wholly north of the Wisconsin glacial its is boundary and not clearly adapted for long-distance dispersal, the species is it Hay appears to have arisen in Maine. transport by the lumber industry could account for the spread oi C. oronensis within the Penobscot River drainage Mowing and confinement there. alter seed dispersal mid-July appears its in to benefit populations. Key Words: Carex oronensis, scoparia bebbii, C. C. ovalis, C. var. fessei- Carex Orono iaia, C. tincta, section Ovales, Cyperaceae, sedge, morphology, Maine, plant endemism, plant conservation Conservation of species often prioritized according lo en- is demism, and plant endemism unusual northeastern North in is America (Gentry 1986). Carex oronensis Fernald apparently is endemic Maine the only plant species (Dibble 1989). to et al. Two Carex other species, C. elachycarpa Fernald and C. josse- (Fernald) Mack, ex Pease, were considered narrow endemics lynii (Fernald 1950) until Reznicek and Ball (1979) placed them in synonymy with Willd. and echinata Murray, C. sterilis C. re- 351 352 Rhodora [Vol. 103 C was spectively. Until February 28, 1996, oronensis listed in Federal Register of Endangered and Threatened Plant Species the as Category a designation for taxa requiring taxonomic reso- 2, On and/or information about lution further distribution. that date, Category 2 was eliminated by the U.S. Fish and Wildlife Service because uneven data quality and insufficient resources to track oi' more 3000 the than species in this category (Office of the Federal Register 1996). Carex oronensis was listed as state Endangered due to restricted ulobal distribution (Dibble et al. 19X9), but is > currently listed as state Threatened because 50 populations have been documented. proposed Concern Special for state is It due to apparent lack o( immediate threats. currently consid- is It G2^ ered fc *S2^ and fcfc using the Natural Heritage ranking system (Haines and Vining 1998). member Carex oronensis a o[ section Ovules Kunth, the larg- is which section the genus, identification "notoriously est in in is numerous difficult" (Reznicek and Catling 1986) because the spe- some morphologically gaps between cies are similar, species are narrow (though deep; A. A. Reznicek, comm.), and some pers. for species groups there has not yet been sufficient taxonomic study Some resolve questionable species. species apparently intergrade to (Whitkus 1988) or hybridize with other species (Fernald 1950; The Gleason and Cronquist 1991). section occurs mostly tem- in perate North America, with some species montane regions in oi' Two members Central and South America. Eurasian section o\^ Ovales, C. macloviana d'Urv. and C. ovalis Goodcn. (= C. lepor- among found North America. The former unique ina are L.), in is (Moore Ovules bipolar distribution and Chater 1971) and in its is more or less frequent in Alaska and northwest Canada but oth- is erwise found conterminous United Carex rarely in the States. oval- thought be introduced. Maine, Ovules represented to In sect. is is is by 22 species and one variety, more taxa than any other section genus (Campbell the 1995). ol' et al. named Fernald (1902) Carex oronensis after Orono, the type locale and the town in which he began his botanical activities. Most authors recognize C. oronensis the species level (Fernald at On 1950; Kartesz 1994). the other hand, Gleason and Cronquist (1991) suggested that a hybrid but specified no putative par- is it ents. Farly collections oi C. oronensis were from the southern Penobscot River drainage (Eastman 1980; Figure and date 1) from 1889-1916. Between 1916 and 1986, only one individual — Dibble and Campbell Orono Sedge 2001] 3 5 3 Ocean Atlantic km 50 Carex Maine, Figure Distribution of occurrences of oronensis, all in 1. U.S.A. showing two unlocated pre- 19 16 (empty squares) and 53 post- 19 16 (filled circles) siles. Three of the filled circles represent multiple sites in — Orono where density is highest. Current sites in five townships (filled tri- angles) could he re-located historic sues, although exact locales for historic collections are unknown. The shaded area the approximate extent of the is Penobscot River drainage. 354 Rhodora |Vol. 103 was was known collected. Until this study (Dibble 1991), little of the morphological distinctness, population size, current distribution, ecology, or reproductive biology for this species. Our primary objective was to ascertain conservation status o( We Carex sought determine geographic oronensis. to distri- its chromosome morphological bution, distinctness, obtain test a its number, characterize breeding system, describe and habitat, its its members see with which other oX Carex Ovules grows. in sect. it MATERIALS AND METHODS We conducted surveys for Carex oronensis intensively field from 1987-89 and intermittently from 1990-98 within about 80 km we the Penobscot River valley (Figure At each oi' I). site collected one mature specimen oronensis (vouchers least C. at oi' members we mainiO and sympatric of Ovules, and at all sect. counted plants o( C. oronensis, listed associated vegetation, and We recorded counted clump oX stems habitat type. a discrete as a C. oronensis individual and included only fruiting plants be- we some members cause cannot identify oX Ovules without sect. mature perigynia. we preliminary survey herbarium examined In a material, o\' approximately 600 herbarium specimens, including representatives American known of North and Eurasian species Ovules all in sect. & us except Carex maackii Maxim, and planata Franch. Sav. to C. Hermann oi Eurasia (Fernald 1950; Gleason and Cronquist 1991; 1974; Kartesz 1994; Mackenzie 1931-1935) from 14 herbaria (BH, CR, MAIN!:, MICH, MT\ NEBC, MIA. NY. NYS, TRT, UNB, US, VT, and We Holmgren examined abbreviations 1990). also wi-:i,c; in et al. New we approximately 290 specimens obtained Maine, Bruns- in Many wick, Newfoundland, and Costa Rica. of the new collections New from Maine and Brunswick were determined or annotated by Rothrock and A. A. Re/nicek. E. P. we Initially included 12 species in sect. Ovules that overlap with Carex oronensis geographic range and resemble in that this We species in morphology, habit, and habitat requirements. selected for numerical analysis the morphological study, those in specimens within each taxon that represent the range o( ap- full We com- parent morphological variation. evaluated 54 characters piled from taxonomic treatments and from herbarium and field observations, then eliminated 32 characters from the preliminary — — Dibble and Campbell Orono Sedge 355 2001] data set because of high variability within and considerable over- among lap taxa. The preliminary analysis identified three species Carex oval- — and OIney and one C. tincta Fernald, C. bebbii variety, C. is, & scoparia Schkuhr ex Willd. Fernald Wiegand, tessellata as var. morphologically closest to C. oronensis, Carex scoparia var. tessellata has been found Maine only locally along the coast east in We oY Penobscot Bay. used only these five taxa in further anal- we with 19 specimens per taxon (Appendix). For ysis, C. ovalis, used nine specimens from North America (but not from Maine, New where specimens from and one from nine Eurasia, rare), is it Some Zealand. character shared by these taxa (includ- states five ing C. oronensis) are loosely cespitose habit (versus densely ces- 4-8 pitose or rhizomatous), spikes per inflorescence, spike (3) (9) arrangement aggregate (versus moniliform), scales dark pistillate brown and reddish with a lighter midvein, perigynia usually less mm Carex than 2,5 wide. Vegetative characters useful in other oi' (Damman studies or floras 1963; Haines and Vining 1998; Rez- nicek and Catling 1986; Rothrock 1991; Standley 1989) proved to be of little value in separating C. oronensis from the four other As we taxa in this study. could find no vegetative characters that we reliably separate these taxa from one another, included only characters that relate to the inflorescence and associated struc- tures. Limitation of taxonomically useful characters to those as- work sociated with the inflorescence in this study parallels in Carex sect. Montanae (Crins and Ball 1983). Our study was di- we rected toward distinguishing oronensis and did not explore C. and more variables that could separate C. ova/is C. tincta defin- We box (McGill visually assessed characters using plots itively. SYSTAT SPSS, 1978) (Version Evanston, Dif- et al. in 6.0; IL). ferences between groups were determined by lack oY overlap between the notched portion boxes on a horizontal axis, and from oi' means and standard deviations. We and scored 10 continuous, discontinuous, attribute 1 1 1 characters (Table 19 specimens each 95) Carex for (total in 1) and scoparia bebbii, C. oronensis, C. ova/is, C. var. tessellata, C. The number sampled tincta (Appendix). oY populations for each taxon ranged from 10-19. For characters and most specimens, all we mean measurements used the oY five replicate per individual five different perigynia from one specimen) to account for (i.e., 356 Rhodora |Vol. 103 Table Twenty-two morphological characters and their slates used in I. Maine the Principal Coordinates Analysis Carex oronensis and lour taxa o\' that resemble The ten continuous characters (noted as : were also used it. ) "0" mm. measurements in a Canonical Discriminant Analysis. All in indi- "I" cates absence, presence. Structure Character Character Stales or Units - Inflorescence lixtent ol aggregation open, the spikelets sepa- *_ *-- - aggregate rate, tiululy 1 - Color chestnut-brown, scales not Pistillate - chestnut-brown I mm Length* mm Width* mm um gyni .ength* Peri I mm Width* mm Distance from base to widest part* mm Distance from base to scrrulation* first Beak - - color dark light, I - Beak margin - dark, hyaline I Base without stipe, — subslipitate i - Adaxial surface without blotch, - rust-colored blotch 1 < 5% measurements accounted intraplant variation; single for o\' the overall dataset. we For 95 conducted Coordinates the individuals, Principal a (PCOR), which recommended mixed Analysis continuous, for is NI\SYS-PC discontinuous, and attribute characters, the soft- in ware (Version Exeter Publishing 100 North Country Ltd., 1.8; NY Gowcfs Rd., Bldg. B, Setauket, 1733), and calculated sim- 1 GOWKR3 program ilarity coefficient using the T. A. Dickinson, ( Museum, ON, Vascular Plant Herbarium, Royal Ontario Toronto. how To Canada). see well groups separate on the basis of the 10 continuous characters (fable and the most discrimi- to find ), 1 we nating these characters, conducted Canonical Discriminant o\' We (CDA) SYSTAT. Analysis with stepwise variable selection in ANOVA examined the continuous characters an and post hoc in comparisons Tu Range (HSD) multiple using key's Studentized = (alpha 0.05) with Bonferoni adjustments. test To chromosome we determine number, buds fixed inflorescence Carex oronensis the early morning Farmer's Solution ol' in in — Dibble and Campbell Orono Sedge 357 2001 Table Continued. 1. Structure Character Character States or Units - Texture adaxial pearly o\' dull, 1 surface Wing - - tooth color dark light, 1 - Adaxial surface nerves weak. nerves - I prominent - Abaxial suture margin - hyaline adaxial light, 1 Nerves Count — Base achene surrounded by spongy oi not spongy tissue, 1 mm Wing width* mm Achene Length* mm Width* m Stipe length* in absolute alcohol :acetic acid, by volume) for 24 and stored (3: hr. 1 C 70% We them squashed and ethanol. anthers stained at 5 in Chromosome with acetocarmine. counts were obtained from cells prophase using Zeiss Standard microscope. in late a I We tested for self- and cross-compatibility using seven individuals of Carex oronensis and two each o( and C. tincta C. we tenera Dewey, which dug from natural populations, mostly in To Orono, and maintained as potted individuals in a greenhouse. we determine were bagged these species self-compatible, intact if inflorescences prior to anther dehiscence on three individuals o\' C. oronensis and one each of C. tincta and C. tenera. wSeeds from common open pollinations of C. oronensis were planted in a gar- den to determine whether the species would breed true. we To Carex test pollen viability in five oronensis individuals, immersed fresh pollen from anthers per plant two drops five in of Alexander's (1969) pollen stain on a glass slide and examined We X after 2 min. 1600. counted more than 200 grains for each at sample. Red-staining pollen grains were counted as unaborted, and those that stained m'cen were considered aborted. As stain- we ability does not necessarily indicate germinability, also germinated fresh pollen from five anthers each for four individuals oY C. oronensis on glass slides two drops of germination me- in CaN0 H dium 250 (agar, 2.5 0, ml: sucrose, 107 0.07 g: g: g: 2 3 , Boron, 0.07 adapted from Stanley and Linskens 1974) 24 for g; room temperature and then examined for germinability hr. at at r Rhodora 358 Vol. 103 I We XI more 200 sample 600. scored than pollen grains per for pollen tube growth. We germinated open-pollinated seeds from live individuals o\ Carex oronensis in the light on moist filter paper following six We weeks of cold storage 5°C. used frequency of achenes at filled as an estimate oi' fruit set in live individuals of C. oronensis selected from different parts of the species range, with a sample of 28 flowers per individual. RESULTS We Morphological study- determined no species Car- that in ex section Ovules from Mesoameriea or from western or south- America was eastern North as close morphologically to C. oronensis species from northeastern North America and Eurasia. as We we found oronensis be and present C. to a distinct entity a description based on our measurements (see below). In an ordi- nation plot the and second Principal Coordinates based on oi' first 22 variables, oronensis and bebbii each separated well from C. C. seoparia van and (Figure C. ovalis, C. tessellata, C. tincta 2). The failure these latter three taxa to form distinct clouds was oi' not because they were difficult to distinguish from each other but we because emphasized oronen- characters that differentiated C. Higher dimensions resolve oronensis and were failed to C. sis. The two Co- otherwise relatively uninformative. Principal first ordinates accounted for 31.5 and 26.6%, respectively, of the total variation in the original variable space, or a total of 58.1%. Carex oronensis and These two closest to C. ovalis C. tincta. latter is on examined. did not separate the basis the characters oi' Canonical Discriminant Analysis on seven continuous characters selected by stepwise analysis resulted perfect classification in The oi Carex oronensis and bebbii (Table other three taxa C. 2). 80% classified least correctly, with three individuals of C. oval- at classifying as C. tincta. Plots various combinations of the is oi' show three canonical axes failed to a discrete cloud for any first taxon oronensis shown). but C. (not Carex oronensis differed markedly from C. bebbii, C. ovalis, C. seoparia var. tessellata, and C. tincta (Figure 3) in perigynium width, perigynium wing width, and achene length (Table stipe 3; The number Figures 4d, 4h, perigynium abaxial nerves 41). oi' was hiuher in C. oronensis than in the other taxa (Figure 4<z). — Dibble and Campbell Orono Sedge 359 2001] 5- X < o CT5 o CO -5 -5 5 Canonical Axis First Figure 2. Plot of Principal Coordinates Analysis for 22 morphological C + characters and 19 specimens each of Carex bebbii C. oronensis (X), ( ). C ovalis (circle), scoparia var. tessellata (square), and C. tincta (triangle). Carex oronensis differed from least one other taxon in of at 1 1 4a— Carex the 12 quantitative variables (Figures but not 4i). 41, oronensis and C. tincta differed from the other three taxa in perigynium scale length (Figure 4a). Carex oronensis C. tincta, and , ovalis were distinguished from bebbii and scoparia C. C. C. var. tessellata perigynium scale width (Figure 4b), perigynium in length (Figure 4c), and distance from the base of the perigynium Achene was to the first serrulation (Figure 4f). width similar in C C. oronensis C. bebbii, and scoparia var. tessellata (Figure \ 4k). In addition to the narrow perigynium and short achene stipe of Carex we oronensis (Table qualitative characters found useful 3), 6 '^j Table 2. Canonical loadings, discriminant function (a), and tabic of frequencies (b) for classifying Carex hebbii. C. oronensis, scoparia and based on seven morphological C. ovalis, C. var. tessellata, C. tincta characters. Canonical loadings and discriminant function. a) Canonical Loadings Discriminant Function Character 1 hebbii o rone lists o veil is esse at a tincta II t 1 Constant 106.07 185.70 213.39 198.82 175.76 7Z Pistillate scale length 0.84 0.18 22.93 34.74 39.86 34.64 25.10 Pistillate scale width 0.51 0.38 68. 105.06 94.62 83.24 93.59 1 I ""' Perigynium length 0.61 0.44 5 44.69 42.75 52.96 43.74 Z 3 w ,i .) .-> . »- Distance from base of perigynium wing to serrulation 0.36 0.34 3 3 7 1.54 0. 15.19 6 3 . 1 1 . Distance from base to widest part of perigynium 0.30 0.18 5 5 -9.46 -10.67 6.50 -9.65 3 . Perigynium wing width 0.24 0.57 21.39 82.93 313.84 28.10 27.41 Achene width 0.14 0.07 10.38 30.06 - .04 21.06 -5.21 1 1 < 'vj