Three new species of Pilea (Urticaceae) from Costa Rica and Panama

5 Pages·2000·2.4 MB·English

by  Alex K Monro

Bull.nat. Hist.Mus.Lond. (Bot.)30(1):7-11 Issued29June2000
Three new species of Pilea (Urticaceae) from
Costa Rica and Panama
ALEX K. MONRO
DepartmentofBotany, TheNaturalHistoryMuseum, CromwellRoad, LondonSW75BD
Synopsis. ThreenewspeciesofPileafromMesoamericaaredescribedandillustrated:P.conjugalisA.K.MonrofromCosta
RicaandPanamawhichmostcloselyresemblesP.pittieriKillip,P. adamsianaA.K.MonrofromPanamawhichmostclosely
resemblesP.pallidaKillip,andP.trichomanophyllaA.K.Monro,alsofromPanama,whichisuniquewithinthegenusinhaving
pinnatelylobedisomorphicleaves.TheaffinitiesofthesespeciesarediscussedandtheirpositionwithinWeddell'ssubdivisions
ofthegenusindicated.
INTRODUCTION occasionallyelliptic; abaxial surfacedryingbrowntogrey-brown,
glabrous, cystoUths fusiform and occasionally disc-shaped, punc-
tate-glandular;baseasymmetricalorsymmetrical, acute,obtuseor
PileaisthelargestgenuswithintheUrticaceaeandoneofthelarger subcordate;marginserrate,frequentlydenticulatetowardstheapex
genera in the Urticales. It is distributed throughout the tropics, ofthelamina,withbasal Vjto Vgentire; apexsymmetrical, acumi-
subtropics andtemperateregions (with theexception ofAustraUa, nate;primaryvenation3-veined,thetwolateralveinsstoppingshort
New Zealand and Europe) and easily distinguished from other of the lamina apex, secondary veins 12-39 pairs, 75-90° to the
NeotropicalUrticaceaebythecombinationofoppositeleavesanda midrib; the minor leaves 16-52 x 8-20 mm, otherwise as major
single hgulate intrapetiolar stipule in each leaf axil. Most of the leaves.Inflorescences6-20perstem, bisexualorunisexual,where
species are small shade-loving forest herbs, many of which are bisexualdominatedbyonesex;peduncleandpedicelssubtendedby
facultativelyepiphyticorepipetric. stipuHform bracts, the peduncular bracts 1.0-1.5 mm, ovate, the
ThelastcomprehensivetreatmentofthegenuswasthatofWeddell pedicellular bracts 0.4-0.5 mm, narrowly deltate to subulate.
(1869),inwhich159speciesandthreespeciesgroups,Integrifoliae, Staminateandstaminate-dominatedinflorescences solitary, 12-68
HeterophyllaeandDentatae,wererecognized.Sincethattimemany mm, bearing 15-300 flowers in aloosepanicle; peduncle Vj to Vj
new species have been described; Index Kewensis (Anon., 1997) inflorescence length, 0.5-0.8 mm in diameter, glabrous; pedicels
lists813speciesnamesworldwide,andestimatesforthenumberof 0.5-0.8X0.2-0.3mm,glabrous;flowersinbudimmediatelypriorto
species range from 500 (Adams, 1970) to 600 (Burger, 1977). anthesis1.0-1.5x0.8-1.5mm,palebrown;tepals4,c. 1.0-1.5mm,
SubsequenttoWeddell's 1857 and 1869 revisions, themajority of elliptictoobovate,glabrous,thesubapicalappendages0.3-0.5nun,
contributions to the taxonomy ofthe genus have come from flora ridge-like,glabrous;stamens4,filaments 1.3-1.8mm,anthers0.8-
t(r1e9a3t6m,en1t9s3,9w)i,tShtmaanjdolreyad&ditSitoenysetromnaeroktr(o1p9i5c2a)l,PAildeaammsad(e19b7y2)K,ilalnidp s1o.l0itXar0y.,5-219.-03m3m.mmPi,stbilelaartienagnd44pi-s1t0i0llaftleo-wdeormsinianteadlinofolsoerepsacneincclee;s
Burger(1977). peduncle V3 to V3 inflorescence length, 0.5 nmi in diameter, gla-
While preparing a revisionary account of Pilea for Flora brous; pedicels 0.2-0.5 x 0.2 mm, glabrous; flowers 0.7-1.0 x
Mesoamericana, 2042collectionsfromCentralandSouthAmerica 0.4-0.5 mm, glabrous; tepals 3, unequal, glabrous, thecentralone
were examined and seven new species described by the author 0.5-0.8mm,oblongtoobovate,withadorsalappendage,thelateral
(Monro, 1999). A furtherthree new species are identifiedhere. In two,0.5-0.8mm,asymmetricallyovate,eachwithadorsalappend-
theabsenceofaphylogeneticanalysis ofPilea, thepositionofthe age. Infructescences24-70 x 0.5-0.8 mm; fruit 1.8-2.0 x 1.3-1.5
newtaxa in relation to Weddell's species groups is indicated after nmi, asymmetrical, compressed elliptic to ovoid, cream to pale
eachspeciesdescription. brown, the ventral margin broadest atthe apex, the dorsal margin
Pilea conjugalis A.K. Monro, sp. nov. Type: Panama, Chiriqui, narrow,thickened.
humidforestbetweenAltodelas PalmasandtopofCerrodela DISTRTOUTION NorthandcentralCostaRicaandwesternPanama
Horqueta, 2100-2268 m, 18 March 1911, Pittier 3230 (NY!- at 1500-2300m.,inpremontaneandmontanewetforest.
holotype).
Fig. 1. Materialexamined.
COSTARICA.Alajuela:AtlanticsideofAltoPalomo, 1900m.Lent1818
Species P. pittieri Killip similis, sed floribus staminatis minimis, (F).Cartage:c. 15kmS.ofTapantialongthenewroad,onE.slopeabove
stipulisminimis,fructibusmaioribus,differt. RioGrandedeOrosi neartheconcretebridge,09°42'N 83''47'W, 1500m.
Hbrearnbchteod,60rooctmi,ngpeartentnhiealb;astee;rreistnrtiealm,odmeosno9e-c5i5ousx.0S.t8e^m.s0ernercnti,, BA1um9re2gr7ei2rc(aB&nM)HL;iiegcsh.nw6earky,m670S99.9°o4f(6FC',aNrMt8O3a)'g';o5b7T'yaWp,aiarn1,U6Q'2u0Re-eb1sre6ar5dv0ae,mC,a1nL4gir0ee0sj-na1e,7r30&0kJmmu,Sd.zGiodefwmPieacznz
weakly striate, drying dark brown to black, glabrous, without 14487(BM);N.andS.slopesofridgeoneasternsideofRioGrandedeOrosi,
cystoliths. Stipules 1.0-2.5 x 1.0-1.5 mm, deltate, membranous, opposite mouth of Rio Humo, c. 6 km upstream from Tapantf, 09°43'N
brown, persistent. Laminas ofleaves at the same node unequal in 83°47'W, 1500-1800m,Grayumetal. 4532(BM);c. 15 kmS. ofTapantf
lengthbyratio 1:1.5-3.0,petiolate,themajorleaves32-121 x 10- alongthenewroad,onE.slopeaboveRioGrandedeOrosineartheconcrete
40 mm, elliptic to ovate, subchartaceous to chartaceous; adaxial bridge,09°42'N83°47'W, 1500m.Burger&Gentry9192(F);c. 10kmS.of
surfacedryingbrowntodarkbrown,glabrous,cystolithsfusiform. TapantfalongthenewroadonE.slopeaboveRioGrandedeOrosi,09°42'N
©TheNaturalHistoryMuseum,2000
A.K.MONRO
Fig.1 Pileaconjugalis{Pittier3230,NY).A.Fertilebranchwithinfructescences,B.Staminateflowerimmediatelypriortoanthesis,C.Stipules.
83°47'W, 1400-1600m,Burger& Stolze5715 (F); c. 10km S. ofTapanti NWofCerroPunta,LasNubesregion,7200ft,Hammel1439(MO);trailto
alongthenewroadonE.slopeaboveRioGrandedeOrosi,09°42'N83°46'W, CerroPateMacho,headwatersofRioPaloAlto,abovePaloAlto,1700-2100
1600m,Burger& Burger7568 (BM,F).Heredia: saddlebetweenVolcan m,08°47'N82°22'W,Knappetal. 4256(MO); c. 0.5 kmE. ofCerroPate
BarvaandVolcanIrazu,headwatersofRioPatria,2200m,Godfrey66148a Macho, headwaters of Rio Palo Alto, 08°47'N 82°21'W, 1800-2100 m,
(MO);ridgesandsteepslopesalongtheRioParaBlanca,CerrosdeZurqui, Knappetal.2114(MO);aboveGuadalupe,c.2kmN.ofCerroPunta,2200
10°03'N84°0rW, 1600-1800m,Burgeretal. 10244(F,MO);RioVueltas m,08°53'N82°33'W,Maas&DressierAMI(F);vicinityofLasNubes,2.7
NW
(upper Rio Patria) on E. slope of Volcan Barva on Caribbean side of miles ofRioChiriqui ViejoW. ofCerroPunta, 2200m, Croat22383
continental divide, 10°06'N 84°04'W, 1900 m. Burger & Gentry 9029 (F, (GH).
MEXU,NY);roadbetweenSanRafaelandRioLasVueltas,alongRioPatria
abovebridge, 10°05'N 84°04'W, 2020-2040m,Stevens 13929 (BM, MO); ThisspeciesfallsintoWeddell'sHeterophyllaespeciesgroup(with
alongheadwatersofRioSantoDomingo,c.3kmE.ofSanRafaeldeVara leaves of unequal length at each node). Pilea conjugalis most
Blanca,N.slopeofVolcanBarva, 10°11'N84°07'W,2060m,Grayum7106 closely resembles P. pittien Killip from Costa Rica. It may be
(BM); Rio Vueltas (upper Rio Patria), E. slope of Volcan Barva near
continentaldivide,10°06'N84°04'W,2000m,Barringer&Christenson3379 distinguished from the latter by stipule shape and size, staminate
(F);baseofCerroZurqui, 10°03'N84°02'W, 1600m,Lent3572(F). inflorescencearrangement,andstaminateandpistillateflowermor-
PANAMA. Chiriqui: CerroPatadeMacho,c. 5 milesNEofBoquete, phology, as summarizedbelow.
trailtocontinentaldivideleadingtoFincaSerrano,Antonio2638(MO);7km Pilea pittieri: stipules 3-18 mm, oblong or obovate, caducous;
THREENEWSPECffiSOFPILEA
staminate flowers borne in 1-5 compactheads, the flowers 2-3 compressed, elliptic, pale brown to brown, the ventral margin
mm; fruit0.8-1.5 mm. broadesttowardstheapex andflattened,thedorsal marginnarrow,
Pileaconjugalis:stipules 1.0-2.5mm,deltate,persistent;staminate thickened.
flowers borne in a loose panicle, the flowers 1.0-1.5 mm; fruit
1.8-2.0mm. Distribution. Known only from the Cerro Tute in Veraguas,
Many collections ofPilea conjugalis have been identified as P. western Panama, at an altitude of 1300-1500 m, growing on tree
gracilipesKillip,aspeciesrangingfromsouthernMexicotonorth- branches inpremontaneandmontanewetforest.
emSouthAmerica. Althoughthereisasimilarityinleafshapeand Materialexamined.
margin,P.gracilipesdiffersinstemcolour,leafisomorphy,staminate PANAMA.Veraguas:vicinityofEscuelaAgriculturaAltoPiedranearSanta
inflorescencearrangement, andfruitsize, as summarizedbelow. Fe,trailtotopofCerroTute,\400m,Antonio201 (MO);vicinityofEscuela
Pileagracilipes:stemdryinggrey-greentogreen;leavesofequalor AgriculturaAltoPiedranearSantaFe, trail totopofCerroTute, 1400m,
subequallengthateachnode,wheresubequalbyaratiolessthan Antonio2014(MO);CerroTuteridgeupfromformerescuelaAgn'cola,Santa
1:1.5; staminate flowers borne in a compacthead; fruit 1.3-1.5 Fe,08°35'N81°05'W, 1400-1450m,Hamilton&Krager4010(MO).
mm.
ThisspeciesfallswithinWeddell'sIntegrifoliaespeciesgroup(with
Pileaconjugalis:stemdryingdarkbrowntoblack;leavesofunequal leaves of equal length at each node and entire margins). Pilea
lengthateachnodebyratio 1:1.5-3.0;staminateflowersbornein adamsiana A.K. Monro most closely resembles P. pallida Killip
aloosepanicle; fruit 1.8-2.0mm. fromCostaRicaandPanama.Itmaybedistinguishedfromthelatter
Thespeciesepithetreferstothepresenceofbothmaleandfemale byitshabit,leaves,indumentum,staminateinflorescence,andfruit,
flowersonthemajorityoftheinflorescencesencountered,aninfre- as sunmiarizedbelow.
quent,althoughnotrare,occurrenceinthegenusPilea. Pileapallida:terrestrial;leavesovate,falcate,lanceolate;leafmar-
Pilea adamsiana A.K. Monro, sp. nov. Type: Panama, Veraguas, pgiendupnrcolmein7e^nitnlfylsoerrersacteen,cbeaslaelngVt^h;tofr'/ujiotf0t.h8e-1l.e0afmemnt.ire;staminate
mountains west ofAlto de Piedras JuniorHigh School north of Pilea adamsiana: epiphytic; leaves oblanceolate or obovate; leaf
Santa Fe, Cerro Arizona (highest peak visible west of school), margin discretely crenulate, basal V3 to V^ of the leaf entire;
1000-1450m,11September1978,//amme/4702(MO!-holotype). staminate peduncle '/^ to ^/j inflorescence length; fruit 1.8-2.3
Fig. 2A-C. mm.
SpeciesP.pallidaKillipsimilis,sedhabituepiphytico,foliimargine Pilea adamsiana is named after CD. Adams, whose previous
discretecrenulato,fructibusmaioribus, differt. work on the genus and assistance with the Flora Mesoamericana
accounthaveprovedinvaluable.
Shrubletorherbto30cm,perennial;epiphytic,monoecious.Stems
repent, sparsely branched, rooting at the base and adventitiously; Pilea trichomanophylla A.K. Monro, sp. nov. Type: Panama,
intemodes6-34x 1.8-4.0mm,weaklystriate,dryingdarkbrownto Bocas del Toro, La Fortuna area, Gualaca to Chiriqui Grande,
grey-brown, glabrous, cystoliths fusiform. Stipules 1.5-3.5 x 1.0- alongoilpipelineroadalongcontinentaldivideW.ofroad, 1300
1.5 mm, deltate, membranous to subchartaceous, grey to brown, m,08°45'N82°17'W,6March 1986,Hammeletal. 14646(MO!-
persistent. Laminas ofleaves at the same node ofequal length or holotype).
subequal, petiolate, 23-115 x 8-27 mm, oblanceolate or obovate, Fig. 2D-F.
chartaceous to subcoriaceous; adaxial surface drying dark brown, Speciesfoliispinnatilobatusacongeneribusdiversa.
glabrous, cystoliths fusiform, rarely 'V'-shaped; abaxial surface
drying red-brown or grey-brown, glabrous, cystoliths fusiform, Herb to 5 cm, perennial; epipetric. Stem repent, little branched,
disc-shaped, rarely 'V'-shaped, punctate-glandular; base symmet- rootingatthebaseandadventitiously;intemodes4.5-12x0.4-0.8
rical, cuneate, occasionally weakly subcordate; margin crenulate, mm,weaklystriate,dryingdarkbrowntoblack,sparselypubescent,
basalV3toV^entire;apexsymmetrical,cuspidate;primaryvenation thehairsto0.8mm,weaklyappressed,crookedorcurved,cystoliths
3-veined, the two lateral veins stopping short ofthe lamina apex, fusiform. Stipules0.8-1.5 x 1.0-1.3 mm, auriculate, membranous,
secondaryveins7-33pairs,75-90°tothemidrib;petiolesequalor darkbrown,persistent.Laminasofleavesatthesamenodeofequal
subequal, 7.5-25 x0.8-1.8mm,glabrous.Inflorescences2-16per lengthorsubequal,petiolate,5.0-13.5x2.5-7.0mm,ovate,pinnately
stem,unisexual,pistillateinflorescencesprecedingstaminateinflor- lobed, membranous; adaxial surfacedrying green tobrown-green,
escences; peduncle and pedicels subtended by stipuliform bracts, sparselypubescent,thehairsto0.5mm,appressed,curved,cystoliths
the peduncular bracts 1.3-2.0 mm, deltate, the pedicellular bracts fusiform;abaxialsurfacedryinggrey-green,sparselypubescent,the
0.5-1.0mm,narrowlydeltatetosubulate.Staminateinflorescences hairs to 0.5 mm, appressed, straight or curved, cystoliths absent,
1-2peraxil, 15-35mm,bearing60-200flowersinasinglecompact eglandular; base symmetrical or asymmetrical, decurrent and/or
head;peduncleVjtoV^inflorescencelength,0.5-0.8mmindiameter, cuneate;marginentire;apexsymmetrical,obtuse;primaryvenation
glabrous;pedicels l.CM.Ox0.3-0.4mm,glabrous; flowersinbud pinnate, secondary veins 3-5 pairs, visible, 60° to the midrib;
immediatelypriortoanthesis2.5-3.5 x0.8-1.3mm,brown;tepals petiolesunequalinpairbyratio 1:1.5-3.0,themajor2.5^.0x0.3
4,3-4mm,elliptic,glabrous,thesubapicalappendages 1.5-2.0mm, mm,theminor1.0-2.5mm,sparselypubescent,thehairsto0.5mm,
narrowlyoblongtoelliptic, frequentlyreflexed, glabrous; stamens erect, crooked. Inflorescences and intact infructescences not seen.
4,filaments 1.5-2.5 mm, anthers 1.0x 1.0mm. Pistillate inflores- Fruit 0.8-1.0 x 0.5 mm, asymmetrical, subcompressed, elliptic,
cences1-2peraxil,c.1mm,bearing24-40flowersinasemi-compact brown,themarginbroad, thickened.
mm
panicle; peduncle V^ to V3 inflorescence length, c. 0.5 in Distribution. KnownonlyfromthetypecollectionfromChiriqui,
diameter,glabrous;pedicelsc.0.8xc.0.4mm,glabrous;flowersc. Panama,growingat1300monarockfaceatthebaseofawaterfall.
1.3 X c. 0.8 mm, glabrous; tepals 3, unequal, thecentralone c. 1.0
mm, oblong to spatulate, notdorsally thickened, the lateral two c. This species falls into Weddell's Dentatae species group (with
0.8mm,oblongtospatulate,notdorsallythickened.Infructescences leaves of equal length at each node and toothed margins). Pilea
12-26 X 0.5-0.8 mm; fruit 1.8-2.3 x 1.3-1.4 mm, asymmetrical. trichomanophyllaisnamedafteritsverydistinctiveleavesandhabit
10 A.K.MONRO
Fig.2 A-C.Pileaadamsiana{Hammel4702,MO).A.Fertilebranchwithstaminateinflorescencesandinfructescences,B.Staminateflowerimmediately
priortoanthesis,C.Fruit.D-F.Pileatrichomanophylla(Hammeletal. 14646,MO).D.Fertilebranch,E.Stipules,F.Fruit.
THREENEWSPECIESOFPILEA 11
(Fig. 2D) which closely resemblethoseofsomefilmyfernsofthe manuscript.IalsothankthecuratorsatBRU,C,F,GH,ITIC,MEXU,MO,
genus Trichomanes. Itis the unmistakable nature ofits leaves and NY,PandUSfortheloanofspecimens.
thefactthatitresemblesnootherknownspeciesfromtheneotropics
whichgivestheauthortheconfidencetopublishthisnameasanew
species despitethe absence offlowers on the specimen.Thereis a REFERENCES
remote possibility that the collection on which this description is
basedisofaprecociouslyfertileplantofanalreadynamedspecies, Adams, CD. 1970. Notes on Jamaican flowering plants 1. Mitteilungen aus der
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Acknowledgements. IthankHelenGreenopforpreparingtheillustra- Museumd'HistoireNaturelle9: l^WO(1856),401-591 (1857).
tions,NormanRobsonandDenisAdamsforhelpwithtranslatingtheLatin 1869.Pilea.InA.deCandoUe,Prodromussystematisnaturalisregnivegetabilis
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