Evidence for Moth and Butterfly Pollination in Gladiolus (Iridaceae-Crocoideae)

15 Pages·2002·11 MB·

by  Peter Goldblatt

MOTH AND
EVIDENCE EOR
Peter and John Manning'^
Goldblatt'- C.
BUTTERELY POLLINATION
IN
GLADIOLUS (IRIDACEAE
CFIOCOIDEAE)'
AlJSTHACT
Pullinalion stratrgies ol (rhuliitlus, one of llu- largest genera ol tlu' nionoeol faniil) liidaceae, are unusuall) diverse,
ami incliuh' xarious liee speciCs, foraging either lor !ie<'tar or foe jjollcn, [)asst»riiie hirils. !ong-j»rohosei(l flies foraginjr
D
fur nectar. Iiojiliirn" Keetles that nse tlu* flo\N(^rs piiinarily as sites foi- asseinhly. and Le|>idi»|)lera. Pollination hy insects
of order comprises tvso ctitiitdy different sets of [>ollinalors, nlglil-flv ing mollis (Noclnidae or Spliingidae) and
tliis
l)nlteillies (evident)} onl) one species ol Salyridae). Tliese lepi(K)pt(Man-pollinatetl (lowers have quite different floral
may
adaptations and both types an* sjiecialist systems, although moth (lowers he jiolHnaled by a range o( diffcTcnl
!nolhs. Tn Gladiolus rn(>lh-|>(>llinateil flowers are usually !arg<\ hmg-tuhed and pale-<M>lored, oi" mottled dull pnij>le to
brown, are usualK richlv scented, often o|)en (ull\ onlv at night, and produce relatively concentrated n<»clar thai Is
open
su(.-rose-rich. Bullcrll) (lo\sers. in cH)nlrast, are full) tluriiig the dav, close partiall) or coniplctcl) at night, are
often bright crimson scarlet, usually with prominent white splashes on the lower but are also large, ha\e a
to le[)als,
long \\i\n\ and [)nHluce quantities of n^lativclv dilute n<^clar, (Mther sucrose-rich or he\osf*-rii'h. Comjiaiing the polli-
Tiation systems of related sfx-cies. we infer that night-flying moth pollination arose 6 limes in the geruis. wliereas
hultcr(l\ [lollination arose tiin<*s in the 16;") s[)ecies o( southern Ahica, and thai the two lepido[)teian [)ollinallon
.'i
systems in Ghulmliis arose quite indept'udentl) of one another.
Kry
words: bulterllies, floral ecology, (datliohis, lridacea<% moths, nectar, pollination systems.
We
l^ollinaliini in ibe a|)pn>\iinalel\ .'Jo gentMa (tf the (C(d(ll)latt el al., 1998a). have also preseiit*^!
Iridareae of suh-Sabaran Africa, wbt^re over 1000 evidence for passcriiK^ bird pollination in Gludiolus
sptH'ies ol llic faniily oi'cur. is rcnuirkably diverse. and reviewed pollination systems for tbe enliii* gc-
Across tbe conlinent pollination systems iiudude ruis (Cohlblatt et al., 1999, 2001). By comparing
four orders of insects (Colcoplera, Diptcra, Hyme- and contrasting the evidence for motb versus but-
noptcra, Lcpidiiptera) and passerine birds, as well pollinati(»n in GladloliLSy we show just Itow
lei'fly
as facidtative, an<! possibly obligate autogamy. Pol- dilferent tbe two systems are tbat use lepidopt(*ran
lination by insects of the orders Diptcra. Ilymcnop- pollen \ectors.
lera, and Tepidoptera is its(d( diverse, involving a l^dlination by large butterflies, so far in Ghidi-
rang(* of families of cacli order and diKeren! sets of olus kn(»wn to in\t)lve only tbe satyrid, Aeropetcs
floral adaptations and associated rewards (o polli- tuUxigliin. bas already Ix'cn demonstrated for two
nators. Here we pn^sent evidence for two (li(ferent sp(^M*^s of Gladiolus and was inferred for several
because
polliitation strategies utilizing Lepido[)lera In tbe mor<' of tbe distinctive floral features j)re-
large, {)redoininantly African getuis Gladiolus. sent in s[^ecies pollinated by tins l>utterfly (Johnson
Klsewhere we have documented passive [)ollination [Jtmd, 1994). These features in(diide a large, un-
i!l
in the gemis by larg<^-lK)dicd apid-anlbo[»horine scented (1ov\(M\ biigbl red pcrianib often with white
hopbine
IxM^s (Coldblalt 1998a), beetles splashes on tbe lower lepals, a narrow but fairly
al..
(*t
(Coldblutl el al., 19981)), long-proboscid flies in the long perianth tube, and the presence of large quan-
www
families Neinestrlnidae and Tabanidat elon- of nectar (J*)bnson Bond. 1994; Goldblall
ilb el lities
iK
*
mm
&
mouth IS X Manning, moth
gate parts <»\cecdin|r ((/oldblatt 1998). Night-flying pollination
O
Mamnng,
1999, 2000), and an active [jollination has been iiderred for nin(^ species of Glddiolus
sysltMU iiivolving j)ollen-collecling fiMuale bees based the presence (ealures commoidv asso-
(tn o(
Support this stud\ by grants 5108-91) and r)991-97 (rom Naliofial Geographic Society gratefulb acknowl-
ft)r llic Is
'
We
W} Rand
edged. thank \\,-K, van k. Alrikaans Universits. Johannesburg, for the nectar anal}scs; R. Kaiser, Ci\andau-
|{(»ure Kesearch Ltd., Switzerland, for scent cheniistr) analvses; and Colin Pat(nson-Jones for the pliotograph of a moth
4
Visiting Glddiolus u
rtjut htfiis.
^ H. A. Krukofi CuraUtr of Alritan Botany, Missouri Botanical (»ar-dcn. V.O. Box 299. bonis, Missouri
St. f).*^U>(),
U.S.A. peter.goldblallC^'mojyol.oig
•* Cinnpton llcrltai iiUM, National Botanical Instilule, P. Bag X7, Claremont 7735, South Africa. manuing(^^nbicl.nbi.
ac./a
Ann. MissouKi Bot. (iAiin. 89: 110-124. 2002.
Volume Number & Manning 111
Goldblatt
89,
1
2002 Gladiolus Lepidoptera Pollination
ciated with moth pollinatidii, incliuliiig a pale-col- lion, absence of floral odor, and often lovvi^r lepals
presence concentrated nee- marked with white splashes (we use the term tepid
ored perianth, of fairly
and a strong, often distinctive scent with a clove lor perianth lobe here),
tar,
component, and some species odor pro-
in floral
&
Manning,
duced only night (Goldblatt 1998).
at sEASONAt.iTY, FI.OK Ai. I'ttKNoixxiY, i.()N(;k\ irv.
Field obs(M'vations and investigation of floral lea-
^j^d i-iohai. n{ESi:N'rAri()N
tures allow us to expand our understanding ol these
phenological observations are prest^iled
systems. Moreover, by using information Direct
pollination
made
and on IH southern African species (Uadiolns
about phylogc^netic relationships g(Muis o(
in thf^
com[taring the pollination s\stems of related spe- during the years 1993 to 1998 in the field (Tabh^
cies, we can infer the number of times that each 1) and in living collections at Kirstenbosch Botanic
mode
system evolved within the genus and suggest an- Gardens, Ca])e Town. Observations include
species, thus developing hypotheses about atid liming of anthcsis (i.e., opening of in(nvidual
cestral
anther dehiscence, expansion of stigiiiatic
the evolution of the floral traits associated with p(il- I)u<ls),
Data
by Lepidoptera. lobes, followed by with(M-ing of thc^ perianth.
lination different
Man-
on seasonably are taken from Goldblatt an<l
were
Compatibility relationships nol
MaTKUIALS and Mi-TIIODS ning (1998).
examined Plant xouchers (Table
the study.
ft)r 1)
KXAMINKI)
SPKCU'.S
Garden
Missouri Botanical
the
are d<'posit(Ml at
Herbarium, Louis (MO), and/or the Coinpton
Observations on the and pollination biology St.
floral
Gape Town
Herbarium.
1993 (INlUi)
of Gladiolus were nuuh* during the years to
1999 southern Africa and living
in the fit-Id in in
Garden.
collections the Missouri Botanical St. NKCrAH A,\ALVSIS
at
and Kirstenbosch Botanic Gardens, Cap**
Louis,
Nectar volume mcasuretn<Mits were taken from
Town. Together with research on the syslemat-
(tur
Man- unbagged flowers the reflecting both rates
ics of the genus (Goldblatt c^ Manning, 199J5: in field,
bom
and ami main-
we have 20 species of secr(^ti<m depletion, i)lants
ning 1999), identified
al.,
<'t
that have flowers likely to be pollinated by Lepi- tained in the laboralor), and not visited by insects
bagged Kxperi-
representing floutas).
doptera from a 165 species of G/ar/mZ/^s that (effectively
total
t)f
Lim[)opo-Cunene River Al ence with Iridaceac has shown that nectar charac-
occur south of the axis.
change species retained
additional 15 species of tropical Africa terislics gradually in in
least
ati
may water periods greater than 24 hours, nectar
(Goldblatt, 1996) ha\e similar flowers and be for tln^
Southern usually becoming more diluted (Goldblatt (H ah,
assmtied be pollinated by Lepid()ptera.
to
Nectar from flowers on cut stems maintained
seven sections 1995).
African species in five of the
fall
was sampled
recognized the genus by Goldblatt and Manning in water in die laboratoiA' therefore
in
Blandus, Hrhen, Homoglossiim, Li- within 18 hours. To collect nectar whole flowers
(1998: sects.
were picked and nectar was withdrawn from the
Acidanihera base of the perianth tube with 3 ^1 capillary tubi-s
genus,
sections of the sectioiis
tional
separating the ovary from the perianth base
after
and Decoratus, AlVica also exhibit fea-
in tro[)ical
and curved allow
(perianth tubes are too elongate
by Lepidoptera.
tures (MmsislenI with polbnatioJi t(»
mouth tube
Gandidates Lepidopteran pollination were nectar rem()val directly via the of tlu^
for
Detaching From
The with a capillary tube). the ])eriatah
recogni/eil bv two separate suites of charact(M-s.
ovary causes minimal damage, and
syndrome moth pollination the top of the
the classic (or
first is
(Faegri & van der Pijh 1979) in which pale flower contamination of nectar by fluid from broken tissu<
volumes
coh)r and protluction of a strong, rich odor are as- is not significant gi\en the large of irectar
under
produced by flowers of species inv(^stigation.
sociated with some features oidy exhibited at night.
haw The percentage of sucrose equivalents in fr-esh nec-
In Clddiolus such flowers are usuall\ lar'ge.
on
was measured the or laboratory a
field
an elongate tube, shorti} exserted unilateral tar iti
floral
and band-hchl refractometer
Beilingham Stardey
stamens, and the strong n<»ral odor is oflen pro-
may (0-50%) or more indixiduals per [)opu-
be five
duced I^i^mcntation froiti
or intensified night.
at
Ad-
unless fewer individuals available.
cream or whilish, but several s{>eiMes have darkly lalion, wer-(^
Whatman
uniformly dark brown perianths. ditional neclar samples were dried on fil-
moltlcd nearly
to
and analyzed by B.-E. van \^>k,
A second syndrome of characters, described in de- ter i)aper no. 1
Rand Joharmesburg. using
Bond combines Afrikaans Lniversity,
Johnson and bright
(1994),
b)
tail
HPLC
sugar analysis.
red pigmentation, a large flag-like i)n^senta-
floral
112
Annals
the
of
Garden
Missouri Botanical
MO
Sludy xmchcr NBG
Taltl*^ 1. sites luu] iiifornialiun for sjHxics stuilicd. Vouclicri are housed al (Goldhall) or al
(nllier colleclors). All sludy sites are in South Africa.
Specieis Stud\ site and \ouelier
ClAniOLVS SFCTION BIANDVS
lilamlus
serii's
W
&
C, cardifudi^ Curl. Cape, near Hain's Kloof. Jan.. Coldhhilt Maiiuing no vouelier
s.n,
W
C, carnnncus C. 11. Wright Cape, cliffs al Heritianus, Feb., Goldhlalt 11292
W
Manning
C. iiisolcns Coldblall *X C. Cape, Piketl)erg. Jaru, GoldhlatI &: Manning 1(}166
J.
W
(i. slf/dniiu' Oberrn. Cape, Polhcrg. Mar., Coldhlatt &: Manning 10176
C
G. Sfmfn'nircfLs I.»*wis Cape. Tsitsikaninia Mis., May, Manning voucher
J. F. s.n. !n>
GIADIOUJS SECTION UNEARIFOUIS
series LineurifoUus
W
Rolus
G, e/n iliac I.. Cape, near Swelleiulani, Mar., Manning 1057
W
Cape, near Kixiersonerend, Mar., Slayner
s.n.
a
W
Boh
gnfhriri Manning
F. is Ca[tc, Bain's Kloof, May, 1080
W
G. ncrincoidcs C. Lewis
CajH', llelderherg Reserve, Somerset West. Run/nds
J. Jan.. 16.3
W
Cape. Jonkershoek Mts., Jan.. EsWrlnnsen 3281-7
GLWIOLVS
SECTION
llEHEA
series Permeabilis
&
G. robiTtsoniac F. B(»lus Mpurnalantra. ru-ar Morg(^nzon, Oct., Goldhlalt Manning 10071
CLiDIOLLS SECTION HOMOGEOSSUIVI
«eri4\s Gracilis
E
G, alliens (Goldhlalt iK J. C. Marniing Cape, near (irahanistown. Mar., Dold Weeks
ct s.n.
W
marnlatns Sweet
G. Cape, Sinionstowu, June, Manning no \oueher
s.n.
DeviTs Peak, May, Manning
no
vouclier
s.n.
W
rrrnrrns
(r. I., Cat)e. llelderhcrg Keserve, Nov., Runnals 513
hi'ries Trislis
W
&
G. h)<dinus Cape, Cydo Manning
Ja( Pass, Sep.. Giddhlaft 9713A
(|
W
Cape, Lion's Head. Aug., Barker 3861
W
G. liliacens Houll. Cajie. FairfieUl, (^alcdon, Sep.. \anni no voucher
s.n.
&
G. longicollis liaker Mpnnialanga, Long Tom Pass, Feh., G<ddldaft Manning 9822
W
G. trislis F. Cape, tu'ar Hredasdorp. Aug., Barker 2814
GLADIOLUS SECTION OPIUOLYZA
s*"ries Oppositiflorus
Moore
G. cruenliis KwaZulu-Natal, Manning 9854
V. Hillcrest, Jan., Goldhlalt
iSc
G. sau/tdersii J. I). Hook. E Cajjc, Naudes Nek, Feb., Goldhlalt Manning 9550
iH'
Additional species with >imilar flowers, assumed he
to adat)!*^! for |»ollination li\ Aerojtetes or uighl-fKing mollis,
G
inchule K
G. aruminatiis Bolus (putalively moths) and slokoei C. Lewis we
(pulalively hullcrnies), hut have no
J.
held ol)ser\ali(Mis of ihe floral ecology of these species. We also lac k oI)scr\ations of insect visitors for G. albcns, G.
carnimens.
G. (rnenlus. G. h}(diniis, G. in.sitlens, and f/. roherlsoniae, \n\\ lhos<* species are included above Itecausc we
ha\c nectar and olhcr dala from study populations.
vu
which was drawn vacuum
\(;l<A^(;l•: by
air a from
a
()uin|>
MtialL cbauibrr open
m lidth'd coritaittirii^ flowers.
iM;oi ral1 scent. was n<it. <Ml1 wi-t.hL .t1he h1 uman nose • ^
*
the fitdd aiul in culti\aled plants. Presence of
POLMNATION MKCHAMSMS AM)
POI.LKN iA)\D
scents too weak U> be diseeiried in the op<Mi air was
\NAIASKS
n^'ordod
alter in(li\idual flowers were picked and
[daccil ill clean, lidded glass jars and stored in a Observations of insects on Ghidiidus flowers
in-
warm
j>la('(\ TIk' e(nitents of each jar was sniffed volved al least 5 hours tola! per s[)ecics atui in
minimum
alter a of 00 mitiules (Buelmiann, 198;}). some eases up to 20 hours total per species. For
Tlu' of scenl production was examined
sit<' by im- species inferred to be pollinated by moths, an ad-
nuwsing
flowt^rs in atpuMuis neutral red stain. Scenl dilional hours of observation was made per sp(-
\
ehemislry was examined
CIvandan-
b) R. Kaiser, cies during daylight hours deternu'ne whether
to di-
Roure Research
Ltd., Switzerland, by gas cliroma- urnal visits by insects might also occur.
tography using a l)B-\Xa\ Ca|)illary colunm (Kaiser, Observations in(dudcd mode of foraging and whelh-
1993). Scents were captured in cai>sules ihrougb er insects contacted anthers and stigmas during
vis-
Volume Number & Manning 113
89, Goldblatt
1
2002
Gladiolus Lepidoptera
Pollination
its to flowers. Stucly populations always included at flowers early in the season, mostly Oetoher and No-
least 20 individuals at evidently undisturbed field veniber. sometimes producing a seeoti<l flowering
sites. Insects o1)S(M'V(m1 to prohe the floral tuhe or flush in December—January. The only otluT species
when
brush the anthers or stigmas were netted the region showing adaptation moth
to of for p(»llina-
blooms
possible and. in die case of rtutdis, then iinmobi- lion in spring before the first rainfall of the
lized in a jar using eth\l acetate fumes. To prevent wet season. This is out of phase witli the main flow-
contamination of the b<Klv of an insect with pollen ering {XMiod for Gladiolus in the summer-rainfall
&
carritnl by anotluM' in the same jar, the bodies of zone (Coldblatt Manning, 1998).
insect specimens were isolated from each oth(M" by In llie winter-rainfall zone. Gladiolus liyalinus,
wrapping them in tissue prior lo i)ituung. bidividual G, liliaceus. and G. Irisfis follow the main fhiwcring
butltM'flies were netted for measuring and observa- pattern U)v the region, Imt (L alhens and G. macu-
tion of sites of pollen depositi<»n and dien released. latus flower early in the season, in autumn or win-
Rod) length and proboscis length of insects was and G. recurrus flowers in late winter or early
ter,
Body
recorded from captured specimens. length spring. Fl(»w<u'ing out of pliase with the fictwering
was measured from the base of labrum peak also chara(^terisiie the two moth polli-
th<' U) \\\v is (»f
tip of the alxlomcn. Mouth-part length was nu^a- nated si)ecies of section Linearifolius, G, cmiliae
sured from the base of the labrum to the tip of die and G. gufhriei, which flower maiidy in April and
proboscis. Night-fljing moths are not easily cap- May, although vegetative growth these two spe-
in
simplv because darkness makes them delayed winter and when
tured cies until ihc s|»ring
diffi- is
cull lo locate. Use of flashlights c<»vered with lrai»s- leaves are produced.
luccnt red cellophane paper for illumination Flowering of butterfly-pollinated species of (Glad-
December
significantly assisted observation and netting of iolus is always from late lo April, excep-
moths. Caj^tured mollis were identified by Douglas tionally May, and this when the *»uly butterfly so
is
Kroon (Sasolburg, S(»ulh Africa), anil both moth and far recorded on Gladiolus species, Aeropctes, is on
&
mrans
butlerfly vouchei' specimens were deposited wilh the wing (Jithnson Bcnid, 1991). 'YW\s that
the South African Museum, Cape Town. for the l)utterfly-polIiuat<'d species of the wlnter-
hlcnlification of polh'u on instxt bodies was done rainfall zon<\ flow'ering occurs several months out
by gently removing grains from the body sinface of phase with the main growth and flowering peak
with a (^lissecting needle. The residue from needle for the region. As a consequence these species
[irobes was collec'led on glass slides and moiuilcd must also have special ecological adaplatious to
may
1-2 adrops o f Call)erlas fluid (OgdtMi et al., support the unusual flowering patterns, riu^se
1974). Pollen grains were idenlifunl microsco[)ical- be a s[)eciallzed habitat, such as clilfs. stream
ly bv comparison with reference |>ollen grain banks, or waterfalls (G. cardinalis. G. lusolms. G.
t(»
preparations nuule from plants flowering at study .sempenv'/ez/.s), or a growth [tattern in which leaf pro-
Gladiolus pollen grains rt^cognlzed by duction occurs w'hen conditions are suitable, later
sites. ait*
their large size, monosulcate aj^Mture with pronii- in the s<*ason {G. rarwinrus, G. stefaniac). or both
2-banded and (C
ncnt operculiun. [)erforate-scabrale neruieoides, G. stokoci),
exine (Goldblatt 1991). Population density aj)pears [o be modrrat*'l\ dif-
et al..
and plants form extended
fuse, j>oj)ulali()ris witli
m
1—3
Rksl;i,ts flowering individuals standing a|)art. S[)ecies
of specialized habitats such as Gladiolus
Irisfis
ILOUAL AM)
StCASONALIl
"^ rili:NOI.()(;V
,
marshy
(moist to sites), G. cardinalis (wat(M-falls), G,
am) ilouvl
i.(>n(;k\ rr^, eiii'siArvrioN ('r\m,K 2)
sandstone semperrireus
carniineus (coastal cliffs). G,
may com-
Flowering times in the (Gladiolus species of (seeps and w(M forest margins) be hu-ally
mon
and dense
southern Africa that are pollinated by night-flying gr(»w in stands.
moths show^ no obvious associalion with their geo- The pattern of flower buds opening on an iuflo-
graphic ranges in the summer- or winter-rainfall reseence is acropetal. In all species, a iTiatme biul
&
expands mid morning, and open
zones of southern Africa (Goldblatt xManning. in the earl) lo the
1998). Flowering of the flora peaks in late spring flow^er tyi)ically lasts four days in Gladiolus species
&
(Si'ptember to November) in the winter-rainfall zone (Goldblatt et al., 1998a; (Goldblatt Manning,
but summer and early autuum (December to 1999). Tn molh-poUinated Gladiolus s|)ecies flow-
in
cuhi\aled sample
March) the summer-rainfall zone. This coincides ering lasts longer. Flo\v(^rs of a
in
with the middle or end of the jx'ritHl of optimal of G, trislis lasted five or six days, and flowers of
C
plant grow^th, during or soon after main rainy recurrus lasted five to nine' days, flowers usually
lh(*
periods. In the summer-rainfall zone, G. longicollis open one to two days ajuut. and hence llu^n^ are
H
»
114 Annals
the
of
Garden
Missouri Botanical
Tal)]*^ 2. Floral arid pticnnlogical data for soullieni African CUuHolus species willi (lowers adapted for pollination
l»\ I.epi{l4>ptera. Species are arranged laxononn'eally according to C/oldblatt and Manning (IW8). IVrianth tube length
was recorded at study sites and may not represerit the range for the species. An asterisk Indicates species flowering
(*)
ont of phase with the peak flowering time for the rainfall zone.
Flow Perianth Main flowering Rainh
I
SpiH'ies color tube (nun) lime zone
Scx'iil
CLxmoLis
SK<:TH)^ iuaisdvs
s«ri«"M Rlatiihis
G. cdnlifKilis red, while streaks :V2~U) none Dec.-F'Vh. winter*
late
on lower
tepals
a
rarmineiis crimson-pink, white ;^()-33 none Fel).-Mar. winter*
streaks on lower tepals
G, insolcns scarlet-red ea. 38 notu Jan. -Feb. winter*
35-15
G. slijaninv red, while streaks none Mar.-Ai)r. wint<M*
on lower
tepals
25-42
G. si'mpcrrircns red, while splashes none Mar-.-Mav winter*
on
lovscr tepals
GLimOUIS UNKARIFOUIS
SECTION
scries LineurifoUus
G, emii7/K,ir densely hrown spe<kle(l 32--t5 strong fruitv Mar.-Apr. winter*
20-27
G. giilhri<'i didl pur[)h'-l)rowii sweet-clove Mar. -June winter*
25-31
G, ncrinrnidrs scarlet none Jan. -Mar. winter*
30-35
slokovi carmnie-rec
nont^ Mar. winter*
(f.
I
CLWIOLVS
SECTION HEBEA
series Pennvubilis
cream 16-22
G. aciunitidtus sweet-floral Aug. -Sep.
winter"
28-
G, robcrtsoniae whit e sweel-clo\c Sep.—Oct. snnnner*
GLWIOLUS
SECTION UOMOGLOSSIJM
Cnirilis
serieaj
G. (ilhctis wliite-creat»i 45-/>( acrid-metallic Mar.-May winter*
nuw
23-35
G. uhiiu. ereani, heavily sjxvkled sweet-doral May-July winter*
\
puiple
l)i-own to dull
G. rrcurrns cn\nn pah* pink 27-36
to swe(*t-clo\'e July-Scp. wniter
8eri«'s Tristis
G. byalinus cream speckled brown, 25-26 usually oilorless Sep. -Nov. winter
pur[)le or green or sweet-clove
G. liliacciLs !>cige, buff or- [tale orange, 40—1-5 sirorrg sweet- Aug.—No\ w rnler
light nian\e at night clove night
at
G. longicullis subsp. cream, lightly speckled 100-110 strong sweet- Sep.-\ o\ srrmmer*
longitollis clove
night
at
white cn^am 85-110 -Dee
to strong sweet- Oct. snnnner*
clove night
at
whne
cream
G. (rislis to lO-f)0 strong sweet Sep. -Nov. wrnter
elov(» night
at
GUniOUIS
SECTION OPUIOLY/A
G. rriienliis red, while on lower le]>als ca. 28 none Jan. -Feb. suninier
33-37
G. saundrrsii led, white on lower tepals none Feb. -Mar. suiumer
often two or niorf* flovvi-rs open at any tinu^ on an Tbc reverse palU^rn holds for butterfly-pollinated
more
iiinorcsccnco of tbree or flowers. Flowers of species. At sunset, the lepals of most species
partly
motb-pollinaled species are usually partly idosed or or fully close, ibc tepals then loosely enclosing the
at l<\ist tbe tepals are flaccid during tlic day, and exserlcil anthers and stigmas. During the day the
o|)cn fully at sunset wIkmi the tepals l)ec<)tne firm tepals Ixvome fully expanded again,
and
fully ext(Mid(Ml. In species of CUidiolus seri(^s Flowers of man> Gladiolus species bave been
Tristis of section Honiogfitssu/n scent is released at found to exbibil mecbanical ])rolandry (Sc<»lt Klliot,
same may &
tlu^ time, although a faitit o(h»r be de- 1891; Goldblatt et al., 1998a; Goldblall Man-
during
tecte(l the da). ning, 1999), and tbe s[»ecies studieil here conform
Volume Number & Manning 115
Goldblatt
89,
1
2002 Gladiolus Lepidoptera Pollination
makes
to this [)attem. The anthers deliisee longitiuhnally e<^nre, rather tlian individual flowers, tliat
one to four hours after the tepals fust unfold. This fur a eonspieuous display (Fiji. IB).
depends some extent on amhienit temperature Flowers pollinated by moths are moderate in size
to
IC-
depending on
and humidity, and anthers dehisce later in wet, cool to large, sectional affinity (Fig.
conditions. Pollen grains are clumptMl together and F). In species of Gladiolus sect. Ilomoglossiun the
23-60
removed perianth tuhe mostly nun long, hut excep-
pollen remains the anther thecae until is
in
mm
85-110
longicoUis subsp. pUityp^
The tionally in G.
bv an insect. three stvle branches, the distal
etalns. The dorsal tepal, usually slightly larger than
adaxial surfaces of which comprise the stigmas, are
mm
32-45
loosely held together for the first three (to live) days llie other five tepals, is long, thus short-
^r to about as long as the lube (Table In Glad-
open and over on the 2).
that tlie flower is lie laxly
Uehea and Linearifolius flowers are
On
^^t'ts.
dorsal surface of the anthers. the last day of '^''^^^^
and acuminalns
^sonunvhal smaller, G. lias a lloral
and branches
anlhcsis, the style elongates the style
mm mm
1^-22 long and 15-21 long.
t"'>^ tei)als
diver-e, arching outward beyond the andiers. At die
lube
Irrespective of sectional affinity, the periantli
same margins
lime, the condu{)licate of the distal
more wider toward
or less cylindric but slighlly
is
half of each style branch unfold, exposing the
'--
"""
^''^^ ''^« ^1«"<^^'" 1"^*^'"
now ''i^' I""*'""
moist, sticky stigtiintic surfaces of tl.e spath- ^^P^^' ^
and lauly straight or gently curved.
i" <lia.neter.
ulate style brandies. Only then are the stigmas of
Flowers are zygomorphic an<l the slightly larger
and
accessible pollen deposition, pollen
a flow(^r to
dorsal tepal typically incdined while the u])p(M-
is
adheres these areas following hand-tiollination.
to
The
lateral te|^als are spread outward. lower te]>als,
days flower open,
riius of the four to six thai a is
upper
usually slightly smaller than three, an*
llie
typically has three to five days in an exclusively
it
and
held loosely together directed fonvard. Tlu*
male phase during which time pollen usually
re-
is
and slamens and arch
style are unilateral to lie
moved from the anthers by insects. Anthers can be
and
close to and just beneath the dorsal tepal ar(^
seen with the naked eye to lack j>oIIen after three
contained within the enclosed space formed
llius
By
or four days flowers were actively visited. the
if
The
by the ascending tepals. filaments are sh<»rtly
time the stigma lobes unfold the flower then in
Is C
cxserted from the tube, or in longicoUis not or
phase
an exclusively femah' that lasts for the final
one
biuely exserted, and the anthers lie parallel to
Mechanical
one (or two) dciys that a flower is open. ,'
^ ^ another wi-t.ih .tihe io- nes otr diehi i• scence rlacin*^ ,towardi
^
^
self-pollination cannot readily occur, even n pollen
thc center of the flower and the lower Ie|)a]s. In
remains in the anthers b) the time the receptive
many
Gladiolus flowers the Icpals
nioth-])ollinaled
because
stigmatic areas an^ (^xposed of the spatial
somewhat
are attenuate with the tips nx'urv<'d, a
and
separation of the pollen-bearing atithers the
most exaggerated aciuuinalus and
feature in G. (i
which we
stigmatic surfaces. GlddiiAas cannineiis,
recurvus.
inckule here as possibly pollinated by large bnt-
Moth-{)oHinaled flowers are cither sliadcs of
we
although lack pollinator observations,
terflies is
^^,,^5^^ ^^ ^.^.^^.^^^^ ^^_. ^^^.^. u^,^^]^ ^^^ ^,^.^^^^^j^. ,^^^^jQ^.j ^^jj,^
an exception. The style divides opposite the base
Fach
IC-F), of
Fig,
^y^j^j^ 2;
^j^^jj j^^^^^,^ ^^^ ,^^.^^^^^,^
of die anthers and style branches are tangled
tlie may
have weakly
three lower a conlrast-
tt^jials
tlie
couhl
deliisced anlh(M-s; thus, selling easily
in th<* darkei median band, often collectively refciitul
in*>„
occur there were no incompatibility system (un-
if Manning,
as a nectar guide (Goldblatt 1908).
to
iS.
known
present). the G. rarminriis study site
at \t
j^^^^ [^.^^^^ ^,f ,],^. ^^.j^.^i^ ^^^l ,i,^ ^\i^y.^\ ^^y^ ^,f ti^^
pollen had not been removed from the anthers, and
^j,^. together form a wide throat leading lo die nar-
become
the stigmatic surfaces dusted with jiollen
row, proximal of the tube. In the sense of Fae-
[lart
same
from antliers of the flower. and van der these are gullet floweis
Fiji (1979),
;ri
tD
conn-
Species of Gladiolus are mediuni-si/ed,
particularly elongated floral tube.
|,^t ^^f[^.^^ ^^-jtl, .^
cm
15-120
bearing geophyles, typically high (Fig. A remarkable feature oi Gladiolus liliaccus the
is
lA-F). Species pollinated by Lepidopltna typically color shift that occurs at sunset. As the tepals be-
produce a single, unbranched flowering stem an- come more extended the normally beige, light
fully
synchronous
uually. Flowering in a population is brown or rusty colored tepals lake on a yell(»vvish
and two four weeks, and inflorescences are background hue with the brown j>igment changing
lasts to
typically secund spikes with the flowers facing to to light blue-mauve. First reptirted by Heniy An-
side and with the floral tube in an ascending drews in 179^!. this color change has intrigued bot-
tlie
c?
C
position. In ncriiicoides the llowi^rs are crowded anists ever since and is thought to be a direct ad-
more moth Manning,
at th apex of flowering stem in or less aptalion to p(»llination (Croldblall l^
tli<^
t*
A
arrangement and entire inflores- 1998). less pronounced color change at sunset
spiral
is tlu-
it
R
116 Annals
the
of
Garden
Missouri Botanical
B
/,
V,
L\fl
m
'^1
I \ p
^t ^rj*
-
^^
ft
':*>
M
h «
F
/
.iui
^tj
Ilk lltlU
Coniparison
Fi»;ui(* 1. of llu* flowers of soutlicrn African (iliuliolns pollirialrd by the sat) rid hultcrfly Acropctvs
tulbaghia (A. U) versus iii>!;lil-nying —moths mostly of the families Noeluidae and Sj)liingidae ((^-F), with longitudin—al
—
some
seetions of (lowers of speeies. A. sempcnire/is Blandus).
(i. (srvi. B. G. nrrineoidcs (seel. IJnrarifolius).
— —
—
C. G. etndiac (sect. Lincarifolius). D. G. macitlatns (seet. Ilonw^lossum). K. G. liliacciis (sect. Uomoglossum).
mm.
G. gufhrlci (seel. Linrarijol/i/s), Scale har 10
Number & Manning 117
Volume
Goldblatt
89,
1
2002 Gladiolus Lepidoptera Pollination
markedly
also occurs in llic related C. hyalinus, tlic Icpals of Neclar of hiiUerfly flowers is variable
which become j)aler ant) more transliiceiil as day- in characler, and ranges from sucrose-dominant (6\
may sucrose-rich crurn-
fades/rhe darkly mottled tepal coloration airdinalis, G. stefaniae) to {G.
liyhl
hc an camoullage, rendering the G. S(uuulcrsu) or hexosc-rich (G. iii.solcns. G.
adaj»tation for fits.
Baker and
nectar or pollen thiincs dur- nerincoides) according to the tlefmtion of
flowers less \isible to
These have
iug the dav. Johnson (1995) has suggested ihat the |}aker (19o;5). nectars also relatively
18-2l7c
maroon pigmentation of the molh-pollinated flowers low concentrations, ranging fr(»m a low of
one
Mo/iadenia (tphrydea Lindl. likewise sucrose equivalents in G, stefaniae [o 26.HV( in
of the orcliid
examined,
camouflage. Moths are believed locate of two populations of G. nerineoides
reprf^sents to
flowers of species solely their scent.
this l)y
Flowers pollinated by the Aeropetes butterfly are KAGKANCK
I
large (Table with the exception o( Gladi-
fairl) 2),
one
Moth-pollinated species of Gladiahis. with
olus nerineoides, and have a pt^rianth lube inainl)
mm
and sweet
exception. [)roduce strong, often rich
15 long, and the dorsal tepal. usually
;?()—
mostly odors (Table Tn species of ^/a(//W//.s series Trislis
sliiihtlv larirer than the other five terxils, is 4).
produced and weak or
35_65 nim long, thus somewhat longtu" lo about fragrance is at niglufall is
twice as long as the tube. In G. nerineoides the e\ idcutly absent during the day. Fragrances vary
human
25-31 considerably as perceived by the nose,
have tube
somt^what smaller flowers a floral
mm
mm com-
and 19-22 thus shorter ihough often appear to liave a strong clove
long lepals l()ng.
{Ma-
The move and thus resemble die scent stocks
ihan the tube. perianth tube is or h^ss [xtiHMit (»f
The odor produced
carnations
cvlindrie but slightly wider toward the apex, with ////oA/) or (/)?a/?/////.v).
mm
the slender lower portion 1.5-2 in diameter. b\ G. alhens (seel. Honioglossiwi) is strikingly dil-
somewhat ami while
and acrid metallic,
and fairlv straight or gently curved. Flowers arc zy- ferent, is
and
goi»iorphic (barely so in G. nerineoides) the
(/-
elements coconut and
larger dorsal tepal either more or less erect, or is fruity, widi of pin(^api)le.
while upper Scent production in G. hyalinus is evidently uu-
lighllv inclinetl (r;. cr//v////^;//.v). tlu' lat-
spn^d The common. j)o[)ulations we examined (Die
outward. lower tepals are In ftuu-
eral tepals
LionV Head, Nienwoudlville).
upper and G\iU) Fass, all
usually slightly smaller than die ihree (^.alg.
ludd loosely logedier and directed forward, rhe in the west of its geographic range, flowers {)ro-
ar<'
and stamens are unilateral and t^xteud out- duced no delectable odor, but collecliou notes with
style
some herbarhim records from the eastern half of
ward, and well exserted from the tube. Kxceptional its
nerineoides has subequal tepals spreading more range indicate die presence of a strong, sweet scent.
G.
combined brown-
\bsence odor with mottled,
and of
angles the tube the (ilaments is
or less right
al
t(»
are included, while the anthers mav be partlv ex- ish or pur|)lisli coloration in these populations.
compounds
belong
Scent m(»stly diileient
serled or entirely included. It)
Butterflv-pollinated fknvers are shades of red. oi chemical classes of scfMits from those of bee-polli-
exceptionally deep pink {(gladiolus e(trmineiis), and nated flowi'is (Coldl)lalt et al., 199J5a), excej)liiig
some
which bee-[)ollinated
the lower tepals are oft(Mi streaked with white. Tn for linalool. is pre^s<^nl in
lower may be almost en- species, notably G. alalus, while ben/yl acetate is
G. saundersii the le[)als
chemical
white with irregular reddish speckling (Table also present in G. jonquiliodorns. ScenI
lirely
among
c(msiderably m(»th-poIlinated
The spe- profiles differ
flowers of the buttei-fly-{K)lliiiated
all
2).
r common
compo-
cies lack deteclabh^ odor (Table 2). Tn the sense of species. e\<-u though linalool is a
compound
and predominant
nent (Table the
Faegrl and van der Pijl (1979), these are flag flow- 1) is
As bee-pollinated species of
ers but with a [)ailicularly elongated floral tube. in C\ nidculdlus. in tlu^
numerous compounds combine produce
and genus, to
The flowers of G. insolens, G. nerineoides. G.
the cliaract(Mislic scent of each species, and as
siokoei are uniformly colored.
many 39 compounds were
as identified in 6'. re-
eurrus (R. Kaiser, pers. couini.). Surpilsingly, G. ac-
NKCrXK
AINAl.^SIS
(TAIiri-, '•\)
Hehea
the species of Gladiolus sect.
luninatiis. otil)
compound moth
examined, shares no with the llow-
Nectar produced by moth-i)olIinal(Hl s[)ecies of
Uonioglossum which be-
Gladiolus sucrose-dominant and ranges in con- ers of species of section to
is
The
((Mitration from a low of 19.5% {G. ennliae) to long the other species analyzed. spicy-clove
and a|>pear
sucrose etiuivahMits. N(u-tarquan- type scents of G. liliaeens G, trislis to
'SG.V/c {G. iristis)
compounds, eugenol the
measured from unbag'^ed flowers, range from tierive fn»m differeiil in
titles,
foiiner and eucaly[>tol in the lalter.
2.2 12.4
to
\x\.
)
1
118
Annals
of the
Garden
Missouri Botanical
Tal)lc Available nectar characlerislics species of souiIhth African Gladiolus pollinated Nectar
il. itf L<'pi(l()ptcra.
l>\
analyses were provided In R.-E. van Wvk. Rand Afrikaans University, Jolianneshurg, Number samples
Soulli Africa. of
same
(n) is die U)V v(»lume and concentration columns. Data marked witb an asterisk arc from Jobiison and Rond
(*)
(1994).
% %
Nectar
Nectar HiUige of sugars
Suf;ai' ratio
Gladiolus volume concentration + G
S/F
fxl
specie (±SD)
Fructose G! urose Su crose
(n)
CIADIOLVS
ION lilANDVS
SEC'l
iilundus
•erit's
canlinalis *9.4 =21.8 9 16 75
It. (12) 3.0
(../a) (1)*
1.7-4.8 26.1 18 30 52
(10) (3.6) 1.08 (1)*
G. In.solciLs 4.a-7.6 39 38 23 0.26
(3)
(I)
8-2
G. stcfaiiide 8.6-11.0 10-16 18-25 59-72
.89
(2)
1
1 (2)
*]0
78
12 3.5
(1)
CIADIOUJS
SECI ION
lIEIiFA
srru-s Permtuibifis
G. robe son iac 8-1.
rt 3. ,"5 (2)
HON
GIADIOUS UNEARltOLWS
SEC
Lined
serii's
rifoliiis
G. cinilidc 5-<)
? 22.;}
(3) (1.5)
7-6
5-9
19..V20..5 8-i:
(2) 7(>-n 4.4
(2)
I
G. ^uthriei 4.4^1.8 :\\A
(5)
(;5.0)
G. fU'ii/u'oidi's Ileldcrber^ l.a-4,2 (6) 2f).8 2-26 23-36 3 7-<)3 1.85
(2.;})
1 (.3)
9-4
Jonkerslioek 28 46
2.3.7
) (3) (2.6) 2( 0..35 (I)
)
GUDIOLIS
SECTION IIOMOGLOSSVM
G
rar
tirriuos
ilh
G, alhcns 3.a-rx6 27.0
(4) (2.2)
G
28-30
ffiaru la 4,8-6.0
fit:s (2)
G. rccurrus 4.1-13.7 31.9 C-7 11-14 80-^2
(6) (2.0) 4.3
(2)
series
Tristis
G. h)alinus C)do Pass 2.2-k7 35.8 2-3 -« 90
9.0
(3) (4.8) I
I (2)
Head
ion 0^1 2-7 80-08
l.i s 13.8
(.3)
G. liliact'iis 3.5-r).4 35.2 2-3 9()-97 26.0
(5) (1.2) 1
(3)
G. lo/i^icollis 2.7-3.7 24.7 6-2 9-2.3 Mi5
(3) (2..5) 5( 2.2
(2)
i
subs[). plat petalus 5.1-7.9 28.3 6-11 6-11
(3) (1.5) 4.3
\
(2)
G
8.5-12.4
tristis .36.4
(5) (2.
GIADIOUS SECnON 1
OPIUOLYZX
G. cruc/itus 4.8-5.7 20.7 26.5 39
(3) 35.5 0.55
(2..5)
(2)
saundrrsii
G. 14.7-2(».l 21.7 15 42 43 0.75
(5)
(1)
POLLINATION MKCIlAM.sMs AND lovo
I'ot.lKN Ghidiohis poUe'ii was recovered from body. This
its
ANAL'^SES
Ijoe slioidd proluihly not be considered a regular
the species since the reward offered
Moth P^^"i'^^t*»^ <^f is
Obsenations
pollination. of pollinalcus
on "'*^ accessible to tbe l^ee, \s\m-h lias a tongue np
7 species of [he 11 pulatively inolb-pollinaletl
sonlbern African CUuliolus species showed ^^ "^'^^ h)ng, while the tube of C. rccwrus is al
of |**
all
27
least miti
lotig.
tltem to be visited by night-flying moths (Table
5).
moth
Hetails of visits are limited because of the
Visitors iniduded sphinx mollis alone {G. longirol-
sphinx and noctnid moths "^liflK-uU) of observing their activity in tlie dark or
lis), (6\ emiliae), or a
under low
range of small and larger moths including Noclni- i?itensity red liglit. Except for species of
dae and oMier families. No other animals not- Sphingidac, moths settled on flowers, grasj>ing the
\v<M-e
ed visiting these sp<M'ies either during the day or l<»wer lepals. before inserting their probosees into
at night exce()ling for a single male /l/i///o/J/(>;Y/ <///- die lloral tube (Fig. 2). Too few visits were noted
make
erslpvs (Apidae; Anlhophorinae) captured while al- <>n ii'iy species for us to observations of the
—
tem[)ting to forage for nectar on the hmg-tubed duration of visits we W(ue dctcrmijied cap-
first
t<»
flowers of <7. recnnus. Its acti\ilies did result in lure visiting moths for id(MUification of species and
contact of both anthers and stigmatic surfaces, and location of sites of pollen deposition. Captured
Number & Manning 119
Volume Goldblatt
89,
1
2002 Gladiolus Lepidoptera Pollination
on
moths were found tarry Gladiolus pollen
lo llie
^
cc
t
CO
*
r o proboscis, hnt no pollen was recovtaed from molli
"^
bodies. After being netted and transferred to a kill-
'-J c ing bottle, moths lose many of their body scales atul
c
c may have any pollen they might hav(^ car-
also
O-i lost
CO
I
W 03
C Nevertheless, moths with elongate pro-
ried. tliose
w
CO
and
bosces, including the sphingids Ilippoiion
CO
and noctuid Cucullia, must be regarded
Agriiis the
-
a; -^ as legitimate pollinators of the species on which
^
r_T
-^
were captured. Moths the families Ai-chii<hie
they in
o
mm
and Ceometridae with shorter prol)osces, 10
o
'^
were captured, camiot reach
long or h^ss, that also
- w
'
I
X and must he regardcfl as
nectar in the floral tul)es
c
accidental visitors, ptuhaps altracled by the slronj r
r-
\0
odors.
floral
Five species (Tabh- S)
Bullerjly polliniilioiu
and
were be visited by Aeropctes tulh(ighi(i
se(Mi U)
C
another four species {Gladiolus carmincits, G.
I and ha\c similar
cruenlus, insolens, G, slokoei)
(r.
a; a;
03 o
and share
CO flowers are infernMl to this polliiiatioti
c
wingspan
Tins large butterfly has a of ca.
stralegv.
mm
80 mm. large bod\ ca. 20 long, an<l a pro-
a
'fi
mm &
boscis 2H-'M long (Johnson Bond, 1994;
was seen
Acropetes fluttering
1994).
J(»hns(>n,
OJ
3 around flowers of G. rardinalis, G. uerineoides. G.
and
saundcrsii, G. sajipenirrns, G, stcfaniac (s])an-
X
V
and
near
a; ning three sections. Btandiis, Ia ifalius,
iC
^w
o
o 00
sometimes
s Ophiolyza, 1able S), settling for 2.S lo
1^
130 and flowers
sei-onds, tluMi to fly to otlu^r ol llit^
same As Johnson and Bonil (1991) have
sp<'cies.
lo
l<:
included inspec-
noted, the behavioi" of buttei-flies
o
o o
c
o^.
when above flowers
tion visits iiuhviduals flutter
During such the
without s(^nling or fe<Mling. visits,
c
may
abdomen, and wings
ventral part of the lliorax.
<
brush against the well-exserted anthers or sligmatic
C
surfaces of species like cardinal G, scmpervi-
is,
a;
a;
and
and Blandus). Pollen
rens, G. stefaniac (sect.
O
a;>
K-
CO Nl
£ stigmatic surfaces of nerinroldes (sect. Line(tri-
* « (f.
£
1>
and saundersii Ophiolyza) are oidy
-^ folius) G, (sect.
o
when
coiUacted during feeding visits insects scUle.
5
and proboscis
grasping lepals inserting their
tlu^
c o
uerineoides pollen
into the pciianth tube. In G. is
0^
CO
because
dei)osited ordy on the upper proboscis tlie
from
anthers arc not or are only shortly exserted
0^
?3
on
Pollen deposited
the tube. tlu' lit^ad,
floral is
rf3
o;
saun-
CO anteiuiae. and dorsal part of the thorax of G,
en
which
und(M
because the liooded dorsal tepal,
dersii
V
the anthers forces a feeding insect to oiienl its
lie,
o; upper
CO body nearly vertically as grasps the lat(M-al
it
o —
CO
No animals were ever seen
'^ lower other
or
tei)als.
1)
those Gladiolus species that attra<'ted Aero-
visiting
3
3 must be assumed be
and single insect to
petes, this
'^
7i
a;
^
^ 3 H their sole [)ollinator.
« 3
IP
o
yj
The innate that Aeropetes exhibits for
attrac'lion
t
f2
red flowers, particularly those of large size, or col-