ISSN 1188-603X

No. 292 June 28, 2002 Victoria, B.C.
Dr. A. Ceska, P.O.Box 8546, Victoria, B.C. Canada V8W 3S2


From: Charles Sheviak []

The following key will facilitate identification of most specimens of Platanthera encountered in the Pacific Northwest. However, some hybridization does occur, and it may be an important factor in some areas. Although in many cases hybrids are intermediate between their parents, or display a mixture of parental features, in some cases they do not. Instead, these plants revert to a basic, presumably ancestral form, with green lanceolate lip and clavate spur about equaling the lip in length. Such plants are generated by hybridization of different species across a wide geographic area. When struggling to identify a plant with such characteristics, it is well to keep this situation in mind. Contributing even further to the problem is a complex of similar forms at the southern edge of the region that may intergrade with Platanthera sparsiflora. This group, which is currently under study, is not yet taxonomically resolved.

The key employs characters of the column which may not be familiar to many who do not routinely work with orchids. When a Platanthera flower is viewed in its normal position, the lip is lowermost (in the species considered here). The column is in the center of the flower, with the anther above the stigma. The anther is composed of two anther sacs separated by the connective. Each anther sac encloses one pollinarium. Each pollinarium is composed of one pollen mass, the pollinium, at the top, connected by a stalk to a sticky membranaceous disc, the viscidium, which glues the pollinium to the pollinator. The viscidia are presented at the lower ends of the anther sacs, which are born on rostellum lobes that position the viscidia for contact with visiting pollinators. In a general way they flank the opening to the spur. The shapes and orientations of these various structures reflect specializations for different pollination syndromes that give rise to mechanical and behavioral isolating mechanisms. Hence they are important characteristics that serve to delimit species.

Key to Platanthera in the Northwest of North America

1. Leaves 1 -- 2, the scape naked or  with  1  to  few  markedly
   reduced bracts ....... 2

   2. Spur   saccate,   lip   broadly  elliptic-suborbicular  to
      obovate, concave.........................  P. chorisiana

   2. Spur slender, lip linear to  rhombic-lanceolate,  more  or
      less flat ......... 3

      3. Leaf  1,  or  if  2, alternate and widely spaced on the
         stem, erect- spreading .................  P. obtusata

      3. Leaves 2 in a basal pair, wide-spreading  and  commonly
         lying on the ground ..................  P. orbiculata

1. Leaves 3 -- several, gradually reduced to bracts upwards .. 4

   4. Column  comparatively  large,  occupying  about 2/3 of the
      hood formed by the dorsal sepal and petals, the  rostellum
      lobes widely spaced, diverging, elevated above the surface
      of  the  stigma  and  connective  and  with them forming a
      hemispherical chamber;  lip  linear  to  linear-oblong  or
      linear-lanceolate or narrowly elliptic, the base undilated
      ........................................  P. sparsiflora

   4. Column  comparatively  small,  occupying less than half of
      the hood formed by the dorsal sepal and petals,  the  ros-
      tellum   lobes  parallel,  diverging,  or  converging  but
      scarcely elevated, at most separated by a narrow slit  and
      not forming a hemispherical chamber; lip linear to linear-
      lanceolate,  rhombic-linear, rhombic-lanceolate, or ellip-
      tic, the base undilated or with an  obscure  to  orbicular
      basal dilation ...... 5

      5. Anther  low  and  appearing to lie atop the stigma, the
         anther  sacs  widely  diverging  from  apices  scarcely
         separated by an obscure connective; flowers autogamous,
         the  pollinia  rotated  forward,  commonly  free of the
         anther sacs and/or fragmenting into loose  masses  that
         trail  downward  onto  the stigma; spur clavate, mostly
         slightly shorter than the lip; lip  rhombic-lanceolate,
         yellowish to yellowish green ..........  P. aquilonis

      5. Anther  high  and  rising  above the stigma, the anther
         sacs more nearly  parallel,  converging,  or  diverging
         from apices separated by an evident connective; flowers
         not    autogamous   (except   sometimes   so   in   P.
         huronensis), the pollinia remaining within the  anther
         sacs;  spur  saccate  to slenderly clavate or filiform,
         much shorter to much longer than the lip; lip linear to
         elliptic or broadly lanceolate or with an abrupt  basal
         dilation, white to green or yellowish ..... 6

         6. Pollinaria  and rostellum lobes parallel to converg-
            ing toward the orbicular viscidia; spur  saccate  to
            spatuloid-capitate or strongly clavate, much shorter
            than lip .............................  P. stricta

         6. Pollinaria  and rostellum lobes diverging toward the
            oblong or sometimes (in P. purpurascens) orbicular
            viscidia; spur  slenderly  cylindrical  to  strongly
            clavate  or saccate, slightly longer to much shorter
            than the lip ....... 7

            7. Flowers pure white, lip usually with a pronounced
               rounded basal dilation, or  rarely  shallowly  3-
               lobed   (  the  broad  dilation  elaborated  into
               forward-directed  lobules);   spur   slender   to
               clavate or slightly capitate [P. dilatata] .. 8

               8. Spur  much  longer  than the lip, usually very
                  slender; typically fragrant only at night
                  ...........  P. dilatata var. leucostachys

               8. Spur shorter  than  the  lip  or  of  variable
                  length,  typically  rather  stout  to clavate;
                  fragrant during the day [plants  with  slender
                  spurs  about the length of the lip may in some
                  cases represent var. dilatata]
                  ..............  P. dilatata var. albiflora

            7. Flowers greenish in general aspect, lip  greenish
               or  yellowish,  mostly  lanceolate  to  ovate  or
               linear, sometimes obscurely  or  prominently  di-
               lated  at the base; spur slenderly cylindrical to
               strongly clavate  or  saccate,  shorter  than  to
               slightly longer than the lip .... 9

               9. Spur  saccate  to clavate-inflated, about half
                  the length of the lip; Lip yellowish green  to
                  dull  yellowish  or  intensely  bluish  green,
                  sometimes marked with  red;  viscidia  usually
                  orbicular;   musty-scented   (central   Sierra
                  Nevada,  California,   where   disjunct   from
                  southern Rocky Mountains)
                  ...........................  P. purpurascens

               9. Spur  slenderly clavate to slenderly cylindri-
                  cal, not inflated and merely  obtuse  to  sub-
                  acute,  somewhat  shorter  to  slighter longer
                  than the  lip;  lip  whitish  green;  viscidia
                  oblong; sweet scented; widespread
                  .............................  P. huronensis

Synonymy of the Platanthera species

Platanthera aquilonis Sheviak, Lindleyana 14:193. 1999.
Platanthera hyperborea auct., non (L.) Lindl.
Platanthera chorisiana (Cham.) Reichb. f., Ic. Fl. Germ. 13-14:128. pl. 435. 1851.
Habenaria chorisiana Cham., Linnaea 3:31 1828; Limnorchis chorisiana (Cham.) J. P. Anderson; Pseudodiphryllum chorisianum (Cham.) Nevski.
Platanthera dilatata (Pursh) Lindl. ex Beck, Bot. U.S. 347. 1833.
Orchis dilatata Pursh, Fl. Amer. Sept. 2:588. 1814.; Habenaria dilatata (Pursh) Hook.; Limnorchis dilatata (Pursh) Rydb.
Platanthera dilatata (Pursh) Lindl. ex Beck var. albiflora (Cham.) Ledeb., Fl. Ross. 4:71. 1853.
Habenaria borealis Cham. var. albiflora Cham., Linnaea 3:28. 1828.; Habenaria dilatata (Pursh) Hook. var. albiflora (Cham.) Correll
Platanthera dilatata (Pursh) Lindley ex Beck var. leucostachys (Lindl.) Luer, Nat. Orchids. U.S. & Canada 225. 1975.
Platanthera leucostachys Lindl., Gen. Sp. Orchid. 288. 1835; Habenaria leucostachys (Lindl.) S. Wats.; Limnorchis leucostachys (Lindl.) Rydb.; Habenaria dilatata (Pursh) Hook. var. leucostachys (Lindl.) Ames
Platanthera huronensis (Nutt.) Lindl., Gen. Sp. Orchid. 288. 1835.
Orchis huronensis Nutt., Gen. 2:189. 1818.; Platanthera hyperborea var. huronensis (Nutt.) Luer; Habenaria hyperborea var. huronensis (Nutt.) Farwell; Limnorchis media Rydb.; Habenaria x media (Rydb.) Niles; Platanthera x media (Rydb.) Luer; Platanthera hyperborea var. viridiflora sensu Luer
Platanthera obtusata (Banks ex Pursh) Lindl., Gen. Sp. Orchid. 284. 1835.
Orchis obtusata Banks ex Pursh, Fl. Am. Sept. 2: 588. 1814; Habenaria obtusata (Banks ex Pursh) Richards.; Habenaria obtusata var. collectanea Fern.
Platanthera orbiculata (Pursh) Lindl., Gen. Sp. Orchid. 286. 1835, p.p.
Orchis orbiculata Pursh, Fl. Am. Sept. 2:588. 1814; Habenaria orbiculata (Pursh.) Torr.; Habenaria orbiculata var. lehorsii Fern.; Platanthera orbiculata var. lehorsii (Fern.) Catling; Habenaria orbiculata var. menziesii (Lindl.) Fern.
Platanthera purpurascens (Rydb.) Sheviak & Jennings, No. Am. Native Orchid J. 3:445. 1997.
Limnorchis purpurascens Rydb. Bull. Torr. Bot. Club 28:269. 1901; Platanthera hyperborea (L.) Lindl. var. purpurascens (Rydb.) Luer
Platanthera sparsiflora (S. Wats.) Schlechter, Bull. Herb. Boiss. 7:538. 1899.
Habenaria sparsiflora S. Wats. Proc. Am. Acad. 12:276. 1877.; Limnorchis sparsiflora (S. Wats.) Rydb.; Limnorchis ensifolia Rydb.; Platanthera sparsiflora var. ensifolia (Rydb.) Luer; Limnorchis laxiflora Rydb.; Habenaria sparsiflora var. laxiflora (Rydb.) Correll
Platanthera stricta Lindl., Gen. Sp. Orchid. 288. 1835.
Limnorchis stricta (Lindl.) Rydb.; Platanthera gracilis Lindl.; Habenaria saccata Greene; Platanthera saccata (Greene) Hultén; Habenaria borealis var. viridiflora Cham.; Platanthera hyperborea var. viridiflora (Cham.) Kitamura; Platanthera hyperborea var. viridiflora (Cham.) Luer

Selected References

Catling, P.M. 1983.
Autogamy in eastern Canadian Orchidaceae; a review of current knowledge and some new observations. Naturaliste Can. 110: 37-53.
Catling, P.M. & V.R. Catling. 1989.
Observations of the pollination of Platanthera huronensis in southwest Colorado. Lindleyana 4: 78-84.
Catling, P.M. & V.R. Catling. 1991.
A synopsis of breeding systems and pollination in North American Orchids. Lindleyana 6: 187-210.
Catling, P.M. & V.R. Catling. 1997.
Morphological discrimination of Platanthera huronensis in the Canadian Rocky Mountains. Lindleyana 12: 72-78.
Correll, D.S. 1950.
Native Orchids of North America North of Mexico. Chronica Botanica.
Luer, C.A. 1975.
Native Orchids of the United States and Canada, excluding Florida. New York Botanical Garden.
Sheviak, C.J. 1999.
Platanthera hyperborea and a reappraisal of green platantheras. No. Am. Native Orchid Journ. 5: 117-141; 198.
Sheviak, C.J. 1999.
The identities of Platanthera hyperborea and P. huronensis, with the description of a new species from North America. Lindleyana 14: 193-203.
Sheviak, C.J. 2000.
Refinements in our understanding of some green platantheras. No. Am. Native Orchid Journ. 6: 88-92.
Sheviak, C.J. 2001.
A role for water droplets in the pollination of Platanthera aquilonis (Orchidaceae). Rhodora 103: 380- 386.
Sheviak, C.J. & W.F. Jennings. 1997.
Platanthera purpurascens. No. Am. Native Orchid Jour. 3:444-449. >/DL>


From: Oldriska Ceska & Adolf Ceska []

During a survey of rare plants on a property that is being developed into a golf course, we encountered Ranunculus parviflorus L., a species not yet reported from British Columbia. It was growing in wet places on the proposed fairways, and it most probably came with the grass seed used for seeding exposed soil. Ranunculus parviflorus is native to Europe (Mediterranean region and western Europe), and in North America it is adventive to the SE part of the USA. In western North America it has been collected in northwestern California (as early as 1922), Oregon (first collected in 1981 - see Madrono 33: 312,313. 1986) and Washington (first collected probably in 1995 - D. Giblin, WTU, personal communication). It was expected to eventually appear in SW British Columbia.

Ranunculus parviflorus is an annual buttercup that occurs in vernally wet depressions. It is a low plant, 5 to 40 cm tall, spreading to decumbent. The lower leaves are 3- to 5-lobed, the upper one are simple. Stem and leaves are pubescent. Flowers are small, 3-6 mm in diameter. Achenes are 2-3 mm with hooked spines and short hooked beak. Receptacle is glabrous. The plant reminded us of a miniature Ranunculus uncinatus. Its potential to become a serious problem in this area is negligible, although in New Zealand it was reported as an unwanted weed in meadowfoam fields (Limnanthes alba).

Voucher specimen: Victoria, Saanich Municipality. Seeding at the fairways of the proposed golf course at the northern end of Creed Road, 48 deg. 28' 16.5" N. 123 deg. 26' 58.0" W. March 10, 2002, A. & O. Ceska, # 32,645


From: Rhoda Love, Native Plant Society of Oregon []
Lesica, Peter. 2002.
Flora of Glacier National Park, Montana. Illustrations by Debbie McNeil. Oregon State University Press, Corvallis, OR. 480 p. ISBN 0-87071-538-0 [soft cover]. Price: US$32.95. Available in bookstores or call 1-800-426-3797 [in US] or 1-800-663-5714 [in Canada]

If you think there is a possibility you might visit Montana be SURE to acquire Peter Lesica's new Flora of Glacier National Park. Better yet, purchase the book now and plan a trip to Montana as soon as possible! This is a wonderful new work -- the first new flora of Glacier Park in more than 80 years. Peter has included everything one could possibly want in a regional flora: a full Introduction which discusses climate, geology, vegetation patterns, history of botanical exploration, floristics, notes on plant geography, and a topographic map of the park The book contains a solid 519 pages with a splendid cover photograph by Lesica of one of our most spectacular mountain species, Xerophyllum tenax, bear grass. The work is the result of twenty years of research on the part of the author who has hiked every trail in the park with, in his words, "a good deal of bushwhacking as well." The floristic summary indicates that 1,182 taxa -- Pteridophytes, Confers, Dicots and Moncots -- are keyed and described. Over one-third of these are illustrated with very effective line drawings by artist Debbie McNeil.

Other strengths are: alphabetical arrangement of families, genera and species, color photos arranged by habitat, nine pages of up-to-date references including our Oregon Flora Project Asteraceae Checklist, an excellent system of coordinating drawings and color photos with plant descriptions, use of synonyms where needed, a nine-page glossary, full treatments of willows, grasses, sedges, rushes and other difficult groups, centimeter ruler on the back cover.

I am so enthusiastic about the new book that I am almost embarrassed to offer a couple of minor suggestions for improvement, but here goes: I would like to see more emphasis on weedy species. For example the floral summary notes 127 introduced species in the Park and it would be helpful to have these listed and also set off in the descriptions with use of a different font as in the Jepson Manual. I would also like to see synonyms treated in a different font in the Index as in the Hitchcock manual. Of the 80 species of Carex described, only 7 are illustrated -- more drawings here would be most helpful, even if they showed only key characteristics. Despite the alphabetical treatments, it would be nice to have a family index inside the front cover. And the map should show the most familiar highway in the Park, the Going-to-the-Sun Road. Finally one last bit of nit-picking: that fantastic Montana state flower discovered by Lewis and Clark, Lewisia rediviva, bitterroot, is, alas, not illustrated in a drawing or colored photograph. Other than these minor items, I find this new work on Glacier Park a extremely welcome addition to our knowledge of the western flora. Congratulations, Peter and OSU Press!

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