A NEW VARIETY OF POTENTILLA GRACILIS (ROSACEAE) AND RE-EVALUATION OF THE POTENTILLA DRUMMONDII COMPLEX

2007·6 MB·English

by  Barbara Ertter

Madrono, Vol. 54, No. 2, pp. 180 186, 2007
A NEW VARIETY OF POTENTILLA GRACILIS (ROSACEAE) AND
RE-EVALUATION OF THE POTENTILLA DRUMMONDII COMPLEX
Barbara Ertter
University and Jepson Herbaria, University of California, Berkeley, CA 94720-2465
and Department of Biology, Albertson College of Idaho, Caldwell, ID 83605-4494
[email protected]
Donald H. Mansfield
Department of Biology, Albertson College of Idaho, Caldwell, ID 83605-4494
Abstract
Field studies and herbarium analyses ofpopulations ofPotcnti/Ia L. sect. Graciles(Rydb.) A. Nels.
with atypical petiole vestiture result in the description of Potentilla gracilis Douglas ex Hook. var.
owyheensis as a new variety, differing from var. ehueri and var. flabeUifonnis in having cottony-
tomentose vestiture on the petioles instead ofappressed to spreading straight hairs. The new variety
grows in mid-montane meadows from the Owyhee Mountains in southwestern Idaho to the Ochoco
Mountains in northeastern Oregon. It is conceivably of hybrid origin, with Potentilla breweri S.
Watson providing the petiole vestiture that is otherwise unknown in Potentilla sect. Graeiles. The
study also resulted in the improved understanding ofPotentillahrueeae Rydb. as a relativelycoherent
taxon centered in meadows around LakeTahoe, California. As a result, Potentilla hrueeae, Potentilla
dnuninondii Lehm., and Potentilla hreweriare recognized as distinct species, with Potentillasuhvillosa
Rydb. and Potentilla anomalofolia M. Peck as synonyms of Potentilla hrueeae. Potentilla versieolor
Rydb. isalso recognized asa distinct species related to P. hreweributdiffering in havingstraight silky
hairs rather than cottony tomentum.
Key Words: Owyhee, Potentilla hreweri, Potentilla hrueeae, Potentilla drunimondii, Potentillagraeilis,
Potentilla versicolor, Steens Mountain.
The Potentilla gracilis Douglas ex Hook, gracilis and subsp. nuttallii (Lehm.) D. D. Keck,
complex is the main component of Potentilla L. P. pectinisecta Rydb., and P. pulcherrinia Lehm.
sect. Graciles (Rydb.) A. Nelson (Rosaceae), This was a significant paring-down from Ryd-
a section restricted to western North America. berg's 1908 treatment of Potentilla for North
Species in the section have erect to ascending American Flora, in which over 40 species in the
flowering stems that arise laterally to clusters of complex (sensu Clausen et al. 1940a) were
palmate (rarely subpalmate to subpinnate) leaves distributed among eight of Rydberg's "groups,"
that arepersistent at anthesis. The inflorescenceis intermixed with multiple other species. Peck
an open, many-flowered cyme in which the nevertheless continued to use Rydberg's species
pedicels remain straight rather than becoming in his Manual of the Higher Plants of Oregon,
recurved in fruit. Flowers open widely at anthesis, recognizing a dozen separate species in the first
with relatively large, yellow, obcordate petals, edition (Peck 1941) and several fewer in the
relatively long slender styles, and numerous second edition (Peck 1961). In contrast, Hitch-
smooth achenes. The P. gracilis complex was cock et al. (1961) went one step beyond Keck and
included in the original biosystematic investiga- included all but P. diversifolia in a highly poly-
tions by Clausen, Keck, and Hiesey (1940a), who morphic P. gracilis, in which they recognized
determined that the chromosomal situation was seven varieties: var. hrunnescens (Rydb.) C. L.
characteristic ofapomictic species, comparable to Hitchc, \m\flabelliformis (Lehm.) Nutt. ex Torr.
that in several European Potentilla species com- & A. Gray, var. elmeri (Rydb.) Jeps. (equivalent
plexes,withhighseedsetinspiteofhighlyirregular to P. pectinisecta), var. pulcherrinia (Lehm.)
meiosis. They also took the "almost bewildering Fernald, var. permollis (Rydb.) C. L. Hitchc,
shuffling"' of morphological characters in most var. gracilis, and var. glabrata (Lehm.) C. L.
populations as evidence that some level ofsexual Hitchc. This varietal approach has been used in
reproduction was nevertheless occurring, often other recent floras in the western United States
giving rise to well-defined ecotypes. (e.g., Ertter 1993; Holmgren 1997; Mansfield
To reflect this complexity in a taxonomic 2000), with var. fastigiata (Nutt.) S. Watson
framework. Keck [in Clausen et al. 1940a) chose replacing var. glahrata. The Potentilla gracilis
to recognize six species in the complex: Potentilla complex is currently being re-evaluated as part of
hrunnescens Rydb., P. diversifolia Lehm., P. the upcoming treatment ofPotentilla in volume 9
flabelliformis Lehm., P. gracilis containing subsp. of Flora of North America North of Mexico,
—
2007] ERTTER AND MANSFIELD: POTENTILLA GRACILIS VAR. OWYHEENSIS 181
which will include keys to and descriptions ofall Description and Discussion of potentilla
taxa. Optimum circumscriptions have not yet gracilis var. owyheensis
been finalized, and will remain provisional due to
the biological complexities noted by Clausen et As a result ofthese field and herbarium studies,
al. (1940a). the "Mud Flat" entity is described here as
The present paper focuses on a series of Potentilla gracilis var. o^vyheensis. For the sake
anomalouspopulationsin Potentilla sect. Graciles of consistency with current floras, we have
that have cottony to shaggy pubescence on the decided to use varietal status, with the realization
petioles, in contrast to the straight appressed to that further study might indicate that the
spreadingpetiolehairs that otherwisecharacterize distinctiveness of var. o^vyheensis, and for that
the section. This focus was triggered by multiple matter other varieties in P. gracilis, is equivalent
collections from the Mud Flat area of Owyhee to that which characterizes apomictic species
County, Idaho, that have a distinct cottony- elsewhere in Potentilla. In the following descrip-
tomentose vestiture on the petioles. Field work tion, leaflet measurements are for basal leaves,
in 2006 confirmed that plants with this vestiture and the largest floral dimensions occur on the
type form relatively uniform populations in the earliest flowers of the season.
Owyhee Uplands of southwestern Idaho. These Potentilla gracilis var. owyheensis Ertter & D.
plants are distinctive enough in other regards Mansfield, var. nov. (Fig. 1)—TYPE: USA,
(e.g., adaxially silver-gray leaflets that are often Idaho: Owyhee Co., northeast ofNickel Creek
secondarily lobed) to stand out when growing in crossing on Owyhee Uplands National Back
mixed populations with other members ofthe P. Country Byway (Mud Flat Road) between
gracilis complex, as is routinely the case. Further Owyhee Mountains and Juniper Mountain,
examination of 30-40 air miles SE ofJordan Valley (Oregon),
specimens in herbaria in Idaho and Oregon shows dry meadow below juniper woodland on
that the taxon also occurs in higher elevations of rhyolitic substrate, 42 32.90'N 116 46.01'W,
southeastern Oregon and is widespread in the ca 5400 fl., 5 Jul 2006, B. Ertter 18688 with D.
Ochoco Mountains, primarily in scattered ''prai- Mansfield and E. Yensen (Holotype UC;
ries" surrounded by mixed conifer forest. isotypes CIC, ID, K, MO, NY, OSC, PR,
Before describing the "Mud Flat" entity as RM, WTU)
a new taxon, it was first necessary to determineits
relation to several of Rydberg's many species Potentilla gracilis var. ehneri et var.flahellifor-
names currently residing in synonymy, most of nn's primo adspectu maxime simile, sed petiolis
which were based only on type specimens. Of gossypinis nec strigosus nec hirsutus.
particular significance is Potentilla suhvillosa Tufted perennial from sturdy branched caudex.
Rydb. (page 316 in Rydberg 1908), based on Stems decumbent to ascending-erect, arising
Hansen 297 collected in 1892 from Carson Spur laterally to leaf tufts, (15-)30-60 cm long, ±
in Alpine County, California. Keck {in Clausen et cottony-tomentose to weakly pilose. Leaves
al. 1940a) considered this collection comparable palmate, the primary leaves basal; petiole (3-)5-
to P. pectinisecta except for the presence ofdense 15( 19) cm long (largest on Steens Mountain), ±
tomentum on the leaves and suggested that it cottony-tomentose, sometimes weakly pilose with
might prove to be subspecifically distinct. Petiole tangled hairs 1-1.5 mm long; leaflets 5 7, ±
vestiture on Hansen 297 does in fact overlap that obovate, the central leaflet (2 )3.5 7 cm long,
ofthe ''Mud Flat" entity, opening the possibility toothed ca. (l/2-)3/4 to midvein with 4 8 teeth
that P. suhvillosa represents the same taxon, per side, the teeth ± tapering from base,
and accordingly an existing available name, sometimes secondarily toothed or lobed, the
although occurring significantly farther south underside ± cottony-tomentose on surface and
with no intervening populations known. Field strigose on veins, the upper side less densely
work at and near Carson Spur in September pubescent but still grayish with a mixture of
2006 confirmed, however, that extant plants cottony and pilose hairs; cauline leaves 14,
comparable to the type of P. suhvillosa from reduced in size. Inflorescence congested at early
the type locality differ sufficiently from the anthesis, openly branched in fruit, comprising 1/
"Mud Flat" entity to be considered separate 4-2/3 ofstem length, (5-)10-60-flowered; pedicels
taxa; i.e., shaggier petiole vestiture and less ± straight, 4 12( 20) mm long, whitely pilose
silvery-gray leaves that are frequently subpal- with a mixture of crisped and fine straight hairs
mate. The Carson Spur material was furthermore <1 mm long. Flowers: hypanthium shallow,
determined to be representative of a relatively externally pilose with loose silky-shaggy hairs ±
mm mm
consistent entity that is locally abundant in l(-2) long; sepals 4 7 long, acute
meadows around Lake Tahoe and that extends acuminate, sometimes purple-tipped; epicalyx
into southern Oregon, with taxonomic implica- bractlets ± narrowly lanceolate-elliptic, 2-5( 6)
tions discussed after the following new descrip- mm long, 1/2 to nearly as long as sepals; petals
tion. broadly obovate to obcordate, ± retuse, (3-)4—
MADRONO
182 [Vol. 54
oFing.pet1i.oleP.otDe.ntiVlelsatigtruacrieliosnvaard.axoiwaylheelenasfilset. tAi.p.HaEb.itV.estB.itBuarsealofleaabfa.xCi.alEnlelaafrlegtemtiepn.tFo.fFclootwteornyb-utdo,mesnhtoosweinvgesptiiltousree |(
vestiture. G. Openedflower. H. Acheneandstyle. (A-GdrawnfromEnter18680and18688; HfromErtter18696.) iil|
2007] ERTTER AND MANSFIELD: POTENTILLA GRACILIS VAR. OWYHEENSIS 183
mm
6(-l 1) long, >sepals, bright yellow; filaments upper Antelope Creek drainage, ca. 5800 ft., 2 Jul
1-3.5 mm long; anthers 0.8 1.1 mm long; styles 1999, D. Mansfield 99-136 (CIC), 8 air mi NE of
1.5-2.5 mm long, ± tapering from somewhat McDermitt, 6400 ft., 12 Jun 2002, D. Mansfield
glandular-thickened base. Achenes ± 1.5 mm 02-417 with H. Kugler. H. Nielsen, & J. Loehrke
long, light brown, smooth. (CIC); Wheeler Co., near summit ofOchoco Pass,
1555 m, 11 Jun 1941, E E. Detling 4841 (ORE).
Additional specimens. USA, Idaho: Owyhee
Co., Mud Flat, 44 mi SW of Grandview, 17 Jun Phenology, habitat, and distribution. Flowering
1943, /. H. Christ 14079 (UC), Cottonwood May to July (August). Growing in vernally moist
Creek crossing on Owyhee Uplands National meadows that dry out during the summer,
Back Country Byway (Mud Flat Road) between surrounded by Artemisia L., Juniperus L., Popu-
Owyhee Mts. and Juniper Mt., 5600 ft., 5 Jul lus tremuloides Michx., Pinus ponderosa Douglas
2006, B. Ertter 18680 with D. Mansfield & E. ex C. Lawson, and/or other conifers, from 1200
Yensen (CIC, UC), same location as Mansfield to 2700 m elevation in the Owyhee uplands and
05-174. 5 Jul 2006, B. Ertter 18696 with D. Ochoco, Aldrich, and Steens mountains of
Mansfield & E. Yensen (CIC, UC), Pleasant southeastern Oregon and adjacent Idaho.
Valley area ca Wj mi. N of Mud Flat Rd., 11 Potentilla gracilis var. owyheensis characteris-
Jun 1980, D. Henderson 5567 with C. Weliner tically occurs in mid-montane meadows that are
(ID), 3 mi SW of Mud Flat on road to Juniper vernally wet but dried by mid-summer. As is
Mt., 7 Jun 1946, B. Maguire & A. H. Holmgren commonly the case for P. gracilis, multiple
26306 (COLO, MO, UC, US, WTU), Mudflat varieties regularly occur in the same meadows,
W
Road 1.4 mi ofJuniper Mt. turnoff, 5670 ft., 9 notably var. elmeri or var.Jlabelliformis and var.
Jun 2005, D. Mansfield05-174 (CIC, UC), Payne fastigiata s.l. In such situations, there is generally
Cabin, Juniper Mt.,ca6150 ft., 14Jul 1971, P. E. at least some level ofecological stratification and
Packard 71-257a (CIC), along Mud Flat Road phenological separation, with var. owyheensis
just past crossing of Battle Creek heading south, dominating the drier periphery of the meadow
5000 ft., 31 May 1993, /. F. Smith 249 (SRP). and tending to have an earlier blooming period.
Oregon: Crook Co., Ochoco Forest, 22 Jun 1932, In some populations (e.g., most of those in
M. E. Peck 17071 (WILLU), Summit Meadow, Owyhee County), there is very little evidence of
Ochoco Forest, 21 Jun 1932, M. E. Peck 17078 intergradation between var. owyheensis and co-
(WILLU); Grant Co., junction of State Rt. 16 occurring varieties of P. gracilis, but some other
and 63 in Summit Prairie, ca 5300 ft., 25 Jul 2006, populations (e.g., Ertter & Smith 18724) include
B. Ertter & J. F. Smith 18724 (SRP, UC), Logan plants with intermediate vestiture on the petioles
Valley, 7 Aug 1946, B. Maguire & A. H. and leaflets.
Holmgren 26900 (NY, UC), moist ground 5 mi Most historical collections ofPotentilla gracilis
E of Austin [duplicate sheet: 5 mi E of Prairie var. owyheensis have been distributed as P.
City], 20 Jun 1938, M. E. Peck 19899 (WILLU), pectinisecta {=P. gracilis var. elmeri) and would
Summit Prairie, 5775 ft., 11 Jul 1937, E. H. Reid key to either this taxon or P. gracilis var.
& R. Collins 554 (ORE); Harney Co., Steens Mt., flabelliformis in regional floras (Hitchcock et al.
Fish Lake, 14 Jul 1943, J.Davis s.n. (WILLU), 1961; Hitchcock and Cronquist 1973; Holmgren
Steens Mt., S side of Fish Lake, 15 Aug 1996, 1997). Peck's collections of var. owyheensis were
Ertter 15232 (CIC, UC), Steens Mt., south leg of variously identified as P. flabelliformis, P. blas-
Loop Road 1.2 mi from rim, ca. 8800 ft., 15 Aug chkeana Turcz., or P. permollis Rydb. PotentUla
1996, Ertter 15253 (CIC, UC), Steens Mt. 15.5 mi gracilis var. owyheensis resembles var. elmeri and
due ESE ofFrenchglen, 7200 ft., 9 Jul 1953, C. G. var. flabelliformis in having leaflets deeply di-
Hansen 341 (OSC), Steens Mt., meadow between vided into slender lobes, but differs from both
Lily Lake and Fish Lake, 31 Jul 1946, B, Maguire varieties, and all other members ofthe P. gracilis
& A. H. Holmgren 26761 (UC, WTU), Steens complex, in having more or less cottony-tomen-
Mt., flat 3/4 mi N of Fish Lake between McCoy tose pubescence on the petioles and both surfaces
Cr. and Big Fir Cr., 7500 ft., 21 Jun 1990, D. of the leaflets. In contrast, the other taxa only
Mansfield 90-286 (CIC), Steens Mt., Fish Lake/ have relatively straight hairs that are spreading to
Blitzen divide across road from Lost Lake turn, appressed on the petioles, and any tomentum is
8160 ft., 23 Jul 1991, D. Mansfield 91-367 (CIC), absent orconfined to the underside ofthe leaflets.
Bear Valley, [N of] Burns, Jun 1937, C. C. PaWrsed As a result, var. owyheensis isconspicuously more
s.n. (OSC), meadow along SilverCreek 6 mi of silvery than co-occurring members of the P.
Riley, 22 Jun 1925, M. E. Peck 13907 (WILLU), gracilis complex. In addition, the leaflet teeth of
Myrtle Park, 5 Jul 1941, M. E. Peck 21009 var. owyheensis tend to be more irregular in size
(WILLU), Steens Mt., open mountain meadows and shape, and are sometimes secondarily
above Fish Lake, 8000 ft., 16 Jul 1935, J. W. toothed or lobed.
Thompson 12133 (UC, WILLU, WTU); Malheur Tentatively included in the current circum-
Co., reservoirca. 5 mi E ofJackson Creek Pass in scription are specimens from near Fish Lake on
MADRONO
184 [Vol. 54
Steens Mountain that have served as the basis for et al. 18775 (Kirkwood Meadow, Amador Co.,
the erroneous inclusion ofPoteutilla quinquefolia CA), and Ertter et al. 18493 (Tahoe Meadows,
Rydb. in Oregon (Peck 1941, 1961; Hitchcock et Washoe Co., NV), all at UC with numerous
al. 1961). These populations were treated by duplicates to be distributed.
Mansfield (2000) as P. gracilis var. ebneri with Comparable herbarium specimens occur fur-
introgression from P. hreweri S. Watson, a high- ther north in California and southern Oregon,
montane species with abundant cottony tomen- allowing for variation in leaf dissection. This
tum. Unequivocal var. owyheensis occurs else- includes the type of Potentilla bruceae Rydb.
where on Steens Mountain {Enter 15253), but from the Warner Mountains of Oregon, which
many of the Fish Lake specimens are unusually has been treated as a subspecies or variety of P.
short, with relatively short styles and intermedi- drunimondii Lehm. in recent floras (Ertter 1993;
ate vestiture. In that Steens Mountain is one of Holmgren 1997). The two taxa, plus P. hreweri,
the areas where P. hreweri is sympatric with comprise the P. drummondii complex as defined
multiple members ofthe P. gracilis complex, it is by Clausen et al. (1940b), which is closely
possible that these intermediate specimens do in related to the P. gracilis complex and shares
fact result from hybridization between the two an equally complex chromosomal situation in-
species. Indeed, introgression from P. hreweri dicating probable apomixis. In conjunction with
could underlie the origin ofvar. owyheensis itself, their transplant experiments on the complex,
thereby accounting for a petiole vestiture type Clausen et al. (1940b) treated P. bruceae as P.
otherwise unknown in the P. gracilis complex. If drummondii subsp. bruceae (Rydb.) D. D. Keck,
so, var. owyheensis is now a well-established but retained P. hreweri as a separate albeit
taxon, with a relatively high degree of morpho- closely related species. They interpreted the
logical and ecological consistency throughout its regular occurrence of intermediates where the
range. species occurred sympatrically, as was frequently
One additional specimen of possible relevance the case, as evidence of hybridization and
to P. gracilis var. owyheensis is a collection by recombination. One of us (Ertter 1992) went
David Douglas from "Valleys of the Blue one step further and treated P. hreweri as P.
Mountains, 1826," seen and photographed by drunimondii subsp. hreweri (S. Watson) Ertter,
one of us (Ertter) at K. The leaflet lobing and with the speculation that subsp. hruceae existed
locality are compatible with var. owyheensis, such primarily as sporadic recurring hybrids between
that the Douglas specimen could represent the the two extremes.
oldest known collection ofan overlooked variety, As a result of the current investigation, this
languishing among unidentified Potentilla for taxonomic stance is being reversed, with Poten-
nearly 180 years. The specimen's original (mis)- tilla hruceae being used at the species level to
identification as Potentilla arachnoidea (Lehm.) accommodate the relatively uniform populations
Douglas ex Rydb. carried a tantalizing hint of noted previously, occurring in northeastern
cobwebby petiole vestiture, although this name is Cahfornia and south-central Oregon. This cir-
a synonym of the unrelated P. pensylvanica L. cumscription includes the type of P. subvillosa
However, close-up photographs made available and probably P. anomalofolia M. Peck, though
to us, and an examination ofthe specimen by R. the latter has more dissected leaves than typical
Brummitt, indicate that the petiole vestiture P. bruceae. Potentilla drummondii in the narrow
consists of relatively straight hairs comparable sense and P. hreweri are also being treated as
to those found in othermembers ofthe P. gracilis species, with P. hruceae and P. drummondii
complex, not the cottony-tomentose hairs ofvar. placed in P. sect. Graciles. Potentilla hreweri, on
owyheensis. the other hand, is provisionally placed in P. sect.
Multijugae (Rydb.) A. Nelson on the basis ofits
Potentilla subvillosa and the pinnate leaves and more prostrate habit, al-
p. drummondii complex though the cottony vestiture and straight pedicels
are anomalous in the section. Such an arrange-
As previously noted, the type of Potentilla ment can only be done with full acknowledge-
subvillosa falls within a taxon that has some ment that hybridization and introgression among
similarities to P. gracilis var. owyheensis but species and across sections is routinely occurring,
which has petioles with shaggier hairs and leaves but this is evidently the norm for apomictic
that are frequently subpalmate, and which occurs sections of Potentilla worldwide.
well to the south of var. owyheensis. Field work Another species closely related to Potentilla
has shown this entity to be a relatively consistent, hreweri is P. versicolor Rydb., which was |
locally abundant taxon in meadows around Lake considered a synonym of P. hreweri by Clausen Ijj
Tahoe, characterized by irregularly subpalmate et al. (1940b), but which Hitchcock et al. (1961) I
leaves and petiole vestiture ranging from villose treated as a synonym ofP. ovina J. M. Macoun, !
to tomentose. Vouchers include Ertter et al. and Holmgren (1997) treated as a synonym ofP.
18770 (Carson Spur, Amador Co., CA), Ertter niillefolia Rydb. Plants comparable to the type of
|]
I
2007] ERTTER AND MANSFIELD: POTENTILLA GRACILIS VAR. OWYHEENSIS 185
P. versicolor are common on Steens Mountain, TYPE: USA, California: ''summit of Mono
Oregon (Mansfield 2000), and also occur in the Pass,"27Jun 1863, W. H. Brewer 1720{Ho\oXypQ
Wallowa Mountains ofOregon (e.g., M. E. Peck US!; isotypes GH! JEPS! UC! YU!)
18484. UC) and the Ruby Mountains in Elko Potentillabrewerivar. expansa S. Watson in W.
County, Nevada (e.g., A^. H. Holmgren & P. K. H. Brewer & S. Watson, Bot. California 1: 179.
Holmgren 10995, UC). Such plants resemble P. 1876. TYPE: USA, California: Sierra Co., 1874,
breweri in habit and habitat but differ in having J. G. Lemmon 64 (Holotype GH!; isotype NY!)
straight silky hairs rather than cottony tomen- Potentilla plattensis Nutt. var. leucophylla
tum. Potentilla versicolor will accordingly be Greene, Erythea 1: 5. 1893. TYPE: USA,
recognized as a distinct species in Flora ofNorth California: Nevada Co., Independence Lake, 26
America and has already been treated as such by Jun 1892, C. F. Sonne s.n. (MO! NY! UC!)
Mansfield (2000). The species is not currently Potentilla millefolia Rydb. var. algida Jeps., Fl.
known from California, but the type of P. Calif. 2: 186. 1936. TYPE: USA, California:
niillefolia var. algida Jeps. from Trinity County, Trinity Co., North Fork Swift Creek, Salmon
California, is transitional from P. breweri to P. Mts.,—July 1909, H. M. Hall 8698 (Holotype
versicolor. UC!) transitional to P. versicolor
The complete synonymy for Potentilla drum-
Potentilla versicolor Rydb.
maosmlhieir,e Pc.irbcruumcsecarei,bePd.,briesweprrie,seanntdedP.bevleorws.icoNloort, 344P.ote1n9t0i8ll.a TvYerPsEic:olorUSRAy,db.O,reNg.onA:meLra.keFl.Co2.2,:
included is Potentilla breweri var. viridis Jeps., Gearhart C'Grayheart") Butte, 9 Aug 1896, F.
awhnidchP.iswehveieldeernitlyS.aWhaytbsroind,baestwpereenviPo.usblryewdeirsi- fVr.agCmoveinltleat&NYJ.!)B. Leiberg 307 (Holotype US!;
cussed by Ertter (1992).
Potentilla drummondii Lehm. Acknowledgments
Potentilla drummondii Lehm., Nov. Stirp. Pug. Special acknowledgements go to Tom Zanoni for
2: 9. 1830. P. dissecta var. drummondii (Lehm.) assistance with the type ofPoteutilUi suhvillosa at NY,
Kurtz, Bot. Jarhb. Syst. 19: 374. 1894. TYPE: to Richard Raise for locating numerous additional
Canada: "in the Rocky Mountains, north of the collections of var. owyheensis in OSC/ORE/WILLU.
Smoking River," Drummonds.n. (E! K! PR!) and toArnold(Jerry)Tiehmforexaminingtheholdings
Potentilla cascadensis Rydb., Mem. Dept. Bot. of RENO. We also thank Richard Brummitt and
Columbia Coll. 2: 109. P. drummondii var. Alison Moore ofthe Royal Botanic Gardens, Kew, for
providing detailed observations and photographs of
cascadensis (Rydb.) Th. Wolf, Biblioth. Bot. 16,
Heft 71: 492. 1908. TYPE: USA, Washington: JaapmreosblFe.matSimcithD,ougStleavsecoMlaltescotino,n aatndK.DaEvriicd YGeonsweenn,
Skamania Co., Chiquash Mts., 14 Sep 1896, provided excellent field assistance and companionship.
Suksdorf 2165 (Holotype NY!; isotypes CAS! The fine artwork by Linda Vorobik is greatly appreci-
GH! MO! UC! US!) ated, as always, and the helpful comments by Jim
Reveal and two anonymous reviewers are gratefully
Potentilla bruceae Rydb.
acknowledged. Support from the Lawrence R. Heckard
Potentilla bruceae Rydb., N. Amer. Fl. 22: 342. Endowment Fund of the Jepson Herbarium is grate-
1908. P. drummondii subsp. bruceae (Rydb.) D. fully acknowledged.
D. Keck, Publ. Carnegie Inst. Wash. 520: 180.
1940. P. drummondii var. bruceae (Rydb.) N. H. Literature Cited
TJHuoYllPm1E8g:9r8e,UnS,MArs,I.nOtCr.eergCmo.onuB:nrtuL.caekFe2l3.0Co13.(,(AH)Wo:alort9n4ye.pre1MN9tY9s!7.;., ClauEEsfxefpenec,rtiJmo.e,fnDtv.aalrDi.esdtKudeeicnevksi,rooannnmtdehneWt.snaMtou.nreHwieoesfsteesyrpn.eci1Ne9os4.r0taIh..
isotypes DS! fragment at UC!) American plants. III. Potentilla gracilis and its
Potentilla subvillosa Rydb., N. Amer. Fl. 22: allies. Carnegie histitution ofWashington Publica-
316. 1908. TYPE: USA, California: Amador tion No. 520: 125-175.
[Alpine on label] Co.: Carson Spur, 1892, G. , , and . 1940b. Experimental
Hansen 297 (Holotype NY!; isotype MO!) studies on the nature ofspecies. L Effect ofvaried
Potentilla anomalofolia M. Peck., Proc. Biol. environments on western North American plants,
Soc. Wash. 49: 110. 1936. TYPE: USA, Oregon: in. Potentilla druiumondii and Potentilla breweri.
K19l3a3m,atMh.CEo..,P3ecmki N168o1f9Kl(aHmoalotthypAegenWcIyL,L1U0 Juiln ErttNCeaorr.,ne5Bg2.i0:e191I97n26s.ti1At9u5t.rieo-nevoafluaWtaisonhionfgtPootnentPiulbllaicdantuino-n
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