Amorphophallus bonaccordensis, a new species of Araceae from India

5 Pages·1994·1.3 MB·English

by  Sivadasan, M

BLUMEA 39 (1994) 295-299
Amorphophallusbonaccordensis,
a new species of Araceae from India
M. Sivadasan N. Mohanan & G.Rajkumar
Summary
Amorphophallusbonaccordensis, anewspeciesbelongingtoAmorphophallussect.Rhaphiophallus
ofthefamily Araceae,isdescribed fromIndia.The sectionischaracterizedby thepresence ofazone
ofneuterflowers betweenthepistillateand staminatezones.
INTRODUCTION
Arecent plantcollectiontripto Agasthyamala Hillson thesouthernendofWestern
Ghats inTrivandrumDistrictofKeralaState,India, yielded anothernewspecies of
Amorphophallus,belonging to sect. Rhaphiophallus (Schott) Engl., and character-
ized by the presence ofa zone ofneuter flowers between pistillate and staminate
zones.
DESCRIPTION
Amorphophallus bonaccordensis Sivad. & Mohanan,spec. nov. —Figs. 1, 2
Ahohenackeri affinis, aquaimprimis differtmarginibusbasi spathaeconvolutis,limbospathaeex-
panso, spathaeinter limbumettubumleviter constricta,appendicespadiciscylindrica,floribus mas-
culinis 2-5-andri insidentibus contextui albo pulvinato.— Typus: Mohanan TBG& RI8219 (K
holo;CAL,M,TBGT,US iso), India,Kerala State,Trivandrum Dist.,BonaccordonAgathyamala
Hillranges, 700 m, 20-iv-1990.
Corms subglobose, 4-8 cm diam.,2.5 cm thick.Leaftrichotomously decompound
withpetiole cylindric, 30-75 cm long,0.8-1.6 cm diam.atbase, slightly tapering
tothetip, smooth,greenwith darkgreenish brownmottles, thelatterfewertowards
thetop portion; rachis ofthe segments 15-20cm long, 0.6-0.8cm thick atbase,
0.3-0.5 cm thick at tip, shallowly channeledaboveand withdecurrentleafbases;
leaflets sessile, ovate to oblong, acuminate atapex, acute atbase, base unequal and
decurrentonrachis, greenish above,palerbelow, margin wavy, varying insize from
6-13cm in length and 3-6.5cm inwidth; primary veins 15-20pairs, closely par-
allel,unitedbelowthemargin forming asubmarginal collectivevein. Stolonsarepro-
ducedfromthecorms ofthefertileindividuals; stolons cylindric,4-5 cmlong,0.4-
D DepartmentofBotany,UniversityofCalicut,CalicutUniversity (P.O.),673 635,Kerala,India.
2) TropicalBotanicGarden & Research Institute, Palode (P.O.), Trivandrum,695 562,Kerala,
India.
296 BLUMEA Vol. 39, No. 1/2, 1994
Fig. 1.AmorphophallusbonaccordensisSivad.& Mohanan. A:Habit,vegetativestate;B:aportion
ofleaflet-margin;C:habit,reproductivestate.
M.Sivadasan,N.Mohanan &G.Rajkumar:Amorphophallusbonaccordensisspec. Nov. 297
Fig.2.AmorphophallusbonaccordensisSivad. &Mohanan. D: Inflorescence;E:pistillate flower;
F: pistillate flower, vertical section; G:pistillate flower,cross section; H: staminate portion of
spadix,crosssection;I: singlestamen, viewfrom broadside;J:stamen, vertical section;K: stamen,
view from top;L;stamen, crosssection.—sa=spadix-appendix; ￿ =pistillate zone; ￿=staminate
zone; ￿ =barrenspadixaxis; φ =zonewithneuterflowers.
298 BLUMEA Vol. 39, No. 1/2, 1994
0.7 cm diam., nodeswith thin scale leavesandfew root primordia. Inflorescence
withpeduncle cylindric, smooth, 30-75cm high, 1-1.6cm diam.atbase, gradually
narrowedtothetip;identicalwithpetioleincolourandpatternofmottles; spathe ovate-
oblong, 12-22cm long, differentiatedintoabasalconvolutetubeandanupperex-
panded limbwithashallowconstrictioninbetween, tip shortly acuminate, 2.5-3.5
cm diam.atconvolute base, 2-3 cm diam.attheconstriction, and 3-3.5cm diam.
justabovetheconstriction. Spadix stipitate,9-18 cm long; stipe to0.5-1 cm long,
0.5-0.6cm diam., light greenish; basalportion of 2-3.5cmofthespadix occupied
with pistillate flowers, middle1-1.5cm withneuter flowers, upper3-3.5 cm with
staminateflowers, andterminal4.5-10cm produced into asterile cylindric barren
appendix; abarrennakedzone of0.2-0.3 cmpresentbetweenthezones withpistil-
late and with neuterflowers, respecitvely. Pistillateflowers subspirally arranged;
ovary sessile, subglobose, 0.18-0.2cm high, 0.2-0.3 cm diam., greenish, 2- or
3-loculed, eachloculewithonesubbasalovule; unicellulartrichomespresenton fu-
nicleandon placenta aroundtheareaoffunicularattachment; style veryshort, cylin-
dric, 0.5-0.8 mmlong, 0.8-1 mm diam.; stigma 2- or 3-lobed, coveredwithshort
unicellularpapillae, cream-coloured,brownishonageing; neuterflowersin1-3rows,
creamywhite in colour, obovoid, 0.2-0.3 cm diam.,fewappearto be transitional
tothestaminateflowers.Staminateflowers closely arranged, eachcomposed of2-5
stamens borneona whitecushion-liketissue of0.8-1 mm thickness; eachstamen
0.1-0.13cm high,inconspicuously 2-lobed; thecaedehisceby narrow apical hori-
zontalslits; spadix-appendix cylindric, 4.5-10cm long, 0.8-1 cm diam.,rounded
atapex, cream incolour, smoothexcept rarely at thebasewhere it maybearsome
very shallow rhomboidally orientedprojections; becomeswarty onageing; infructes-
cence notobserved.
Etymology - Thespecificepithetis indicativeofthenameofthetypelocality.
Distribution- Thespecies is hithertoknownonly from thetype locality.
INTERRELATIONSHIPS
OtherIndianspecies hithertoknown as belonging toAmorphophallus sect.Rhaphio-
phallus areA. hohenackeri(Schott) Engl. & Gehrm.,A. margaritifer(Roxb.) Kunth,
A. mysorensis Barnes& Fischer (1939), A. sylvaticus (Roxb.) Kunth, A. smithson-
ianus Sivad. (Sivadasan, 1989), andA. konkanensis Hett., Yadav & Patil(Hetter-
scheidetal„ 1994).
Engler (1911), inhisrevision ofthegenus,hadtreatedA. hohenackeriandA. syl-
vaticusundertwo separatesections, viz. sect.Rhaphiophallus andsect.Synantherias,
respectively. Amorphophallus margaritiferwas treatedunderthegenusPlesmonium
Schott. Amorphophallus bonaccordensisclosely resemblesA. hohenackeriinits
general morphological features,butinthelatterspecies thematurespathe iscompletely
openthroughout itslengthwithoutabasal convolutetubularportion; thelimbofthe
spatheisovate-lanceolatewithsubacuminatetip;the spadix-appendix taperstothetip
andreachesalmost to thetop ofthespathe. InA. bonaccordensisthespathe is ovate-
oblong, withaprominent basalconvolutetubularportionseparated fromtheoblong
limbbyaslight constriction. The spadix-appendix is cylindric withroundtip andis
M.Sivadasan,N.Mohanan&G. Rajkumar: Amorphophallusbonaccordensisspec. Nov. 299
much shorterthanthespathe, andneverreaches thetipofthespathe. Anothermost
significant characternotedis thenature of thestamens whichare foundin groupsof
2-5,borneonawhitecushion-liketissue.
The presenceofa barrenaxis between thepistillate andneuter zones is ofmuch
significance in thepresumedevolutionofAmorphophallus sect.Rhaphiophallus. In
A. longiconnectivus Bogner & Mayo, anewspecies from CentralIndiatobe pub-
lishedshortly (Mayo, pers. comm.) thereis a zone ofbarrenaxis ofthespadix be-
tweenthepistillate andstaminatezones withoutany neuter flowers. This conditionis
presumed tohaveevolved bythecomplete reductionoreliminationofneuter flowers
as evidencedby intermediatemembersasA. bonaccordensis, wherebothashortbar-
ren axis andfewneuter flowers arepresent.
ACKNOWLEDGEMENTS
We thank Dr.P. Pushpangadan,Director TropicalBotanic Gardenand Research Institute,Trivan-
drumforencouragement.Weexpressoursincere gratitudetowardsDr. DanH.Nicolson,Department
of Botany,Smithsonian Institution,Washginton, D.C.,USA forcorrection ofthe Latindiagnosis
and criticalcomments on the manuscript, and Mr. K.P. PradeepKumarfor the excellent illustra-
tions.
REFERENCES
Barnes,E.,& C.E.C.Fischer. 1939.Amorphophallusmysorensis. In:LXVIII.New orlittle-known
plantsfrom Southern India: XI.Kew Bull.Misc. Inform. 10:661.
Engler,A.1911.Araceae-Lasioideae. In:A.Engler(ed.),Das Pflanzenreich IV.23C,Heft48.Leip-
zig.
Hetterscheid,W.L.A.,S.R.Yadav & K.S.Patil. 1994.Notesonthe genusAmorphophallus(Ara-
ceae)5. Amorphophalluskonkanensis,anewspecies fromIndia,and taxonomic reflections on
AmorphophallussectionRhaphiophallus. Blumea39: 289-294(this issue).
Sivadasan,M. 1989.Amorphophallussmithsonianus (Araceae),anewspeciesfromIndiaand anote
onA. sect. Synantherias.Willdenowia 18:435-440.