The Phylogeny and Classification of the Diseae (Orchidoideae: Orchidaceae)

27 Pages·1994·11.1 MB·

by  H P Linder

PHYLOGENY AND
THE
H. P. hinder2 and H. KurzweiP-3
OF THE
CLASSIFICATION
DISEAE (ORCHIDOIDEAE:
ORCHIDACEAE)
1
Abstract
The
subtribal classification of the Diseae (Orchidoideae) is reviewed in light of the available morphological, leaf
anatomical, and palynological data. These data are critically assessed, and the more prominent features are illustrated.
The data are analyzed cladistically, and the robustness of the various components of the most parsimonious tree
is
assessed by a bootstrap analysis. Based on the cladistic analysis and the bootstrap analysis, a new classification
is
proposed for the Diseae. The results of the bootstrap analysis are used to establish the nodes at which formal taxa
should be recognized. This classification recognizes five monophyletic subtribes: the Satyriinae, Disinae, Brownleeinae
new
(a sub tribe), Huttonaeinae, and Coryciinae. suggested that Brownleea, the only genus of the Brownleeinae,
It is
may
be of hybrid origin, as shares the autapomorphies of the Disinae and Coryciinae. Huttonaea shown to be
it is
more
closely related to the Diseae than to the Orchideae, and consequently included as a subtribe of the Diseae.
is
Ine new
classification formally presented, and a key to the genera provided.
is is
&
The Diseae are a tribe of largely terrestrial Af- Bentham in Bentham Hooker (1883), who rec-
rican orchids, which include the spectacular Disa ognized four subtribes: Euophrydeae (Serapieae),
uniflora Bergius, the morphologically complicated Habenarieae, Diseae, and Corycieae. The former
The
subtribe Coryciinae, and the striking Huttonaea two are not being considered here. Corycieae
grandiflora (Schltr.) Rolfe. There are several sub- are identical to the Coryciinae, Disperideae, or
tnbal classifications available, none of which have Disperidinae recognized by Pfitzer (1889), Kraenz-
been 899- (1912-
carefully substantiated in terms of their char- lin 1 1 900), Schlechter 1 898), Rolfe
( (
acter support. While some of these subtribal group- 1 9 1 3), Senghas ( 1 973- 1 974), and Dressier ( 1 98 1 ).
may
ings be monophyletic, recent data indicate They denned the Corycieae as having adnate petals
that several genera are probably misplaced, ren- and dorsal sepals, with lips fused to the gynostem-
dering other groups ium bases and often appendiculate, and included
paraphyletic.
I he taxonomy at the species level has been Pterygodium, Corycium, Ceratandra, and Dis-
completely The only changes over the
revised for taxa excluding the extra- peris in the subtribe.
all
South African species of Disperis and Satyrium, past century to this group have been in the delim-
nd even for these genera several local revisions itation of the genera (for a review and phylogenetic
nave
been produced see Kurzweil et 1991).
recently. In both the subtribes classification, al.,
&
Coryciinae The Bentham Hooker (1883) have
(Kurzweil 1991) and Disinae Diseae of
et
al.,
(Under, & The
1986; Linder Kurzweil, 1990), there had a more complicated history. authors de-
nave been attempts at reviewing the generic clas- fined this subtribe by its reflexed anther and the
They mod-
sification. But there are several indications that the large, subterminal stigma. included the
1973-1974;
subtribal classification may not be as sound as ern Satyriinae (Senghas, Dressier,
1973-1974;
suggested by Linder 986). A study of Huttonaea 1981), Disinae (Senghas, Dressier,
1
(
(Kurzweil, 1989) indicates certain affinities to the 1981), as well as three genera of the Orchideae
and Platycoryne)
°ryciinae, and a recent study on Brownleea (Lin- (Brachycorythis, Schizochilus,
&
er 889) followed
Kurzweil, in prep.) suggests the same. in the subtribe. Pfitzer 1 substantially
(
1 he first attempt to subdivide the Orchidoideae Bentham and Hooker, but named the group the
(tribe OnrirvH«o~ ^t i n„.. loon iQ/in\ «.,oo w«r Satyrieae. Kraenzlin (1899-1900) removed the
:
Supported The second author also ac-
' by the Foundation for Research Development, Pretoria, South Africa.
novvledges
the support of the Smuts Memorial Fellowship.
°°
,us Herbarium, University of Cape Town, Rondebosch 7700, South Africa.
,
Current Bag Claremont 7735,
address: Compton Herbarium, National Botanical Institute, Kirstenbosch, P. x 7,
^"th
Africa.
Ann. Missouri Bot. Gard. 81: 687-713. 1994.
)
Annals of the
688
Garden
Missouri Botanical
A
Table comparison of the tribal and subtribal classifications of the Diseae sensu lato.
1
.
&
Bentham Hooker (1883) Diseae Corycieae
Pfitzer (1889) Satyrieae Corycieae
Rolfe (1912-1913) Diseae Corycieae
Schlechter (1927) Disaeinae Disperidinae
Schlechter (1926) Satyrieae Diseae Disperideae
Senghas (1973-1974) Satyrieae Diseae
Satyriinae Disinae Disperidinae
98
Dressier Diseae
1
( 1
Satyriinae Disinae Coryciinae
last three genera and placed them, in our opinion, based on flower resupination and other striking
way more
in their correct groupings. This narrower definition features. In this Rolfe upset the synthetic
of the group was followed by subsequent authors approach of Schlechter (1901), who recognized
all
(Schlechter, 1901; Rolfe, 1912-1913; Senghas, very wide genera that were generally monophy-
&
1973-1974; Dressier, 1981). As Bentham letic. The generic limits in the Coryciinae were
Hooker's definition of the subtribe uncannily recently assessed by Kurzweil et (1991), and
al.
is
accurate, their inclusion of these three genera in detailed arguments on the monophyly of the genera
the Diseae must have been based on inaccurate are presented there. The subtribe Disinae still pre-
morphological information. The recognition that sents a problem. Lindley (1830-1840) already
there are two subgroups within the Diseae (sensu commented on the difficulty of establishing groups
Schlechter and Rolfe) finds expression in the formal within the broad genus Disa, and all attempts at
1973-
recognition of separate groups (Senghas, establishing an empirically sound generic classifi-
1974; 1912-1913; Schelpe,
Dressier, 1981). cation have failed (Rolfe,
&
The
first suggestion to combine the Satyriinae, 1966; Under, 1981a-f, 1986; Under Kurzweil,
Disinae, and Coryciinae into a single tribe, the 1990). Although the presently recognized segre-
Diseae, was by Dressier (1979), but has not been gate genera are clearly monophyletic, their rela-
accepted by Szlachetko (1991). Other authors used tionship to the large core genus Disa is not clear,
every single combination possible: these are sum- and certain that the recognition of a distinct
it is
marized in Table 1. genus Herschelianthe renders Disa paraphyletic
Huttonaea has had a checkered history. Ben- In this treatment the genera as established by Un-
&
tham Hooker evidence
883) placed the genus between der (1986) are used, despite the clear
1
(
Bartholina and Holothrix in the Habenarieae, while that Disa paraphyletic. The generic limits in the
is
from a
Pfitzer (1889) and Kraenzlin (1899-1900) subtribe Satyriinae have not yet benefitted
in-
demon-
cluded the genus in the section Gymnadenieae. This However, Under (1989)
detailed study.
approach was followed by Rolfe (1912-1913). monophyly Satyrium relative to ba-
strated the of
The
Senghas (1973-1974)
and Dressier (1981) sepa- tyridium and showed that both can be upheld.
rated Huttonaea into its own subtribe in the Or- genus Pachites, which comprises two species, is
chideae, the Huttonaeinae, and noted that had poorly known, due great rarity, but there is
to
it its
no close relatives. They placed in the Orchideae unpublished information that casts doubt on the
it
because unpubhshe
of its apparently erect anther. monophyly of the genus (Kurzweil,
The
delimitation of the genera in the tribe has data), and consequently we treat the two specit
been
a persistent problem, and
different treatments separately here.
on
vary The based
greatly. original generic delimitations were These have been heavily
classifications
established by Swartz (1800), and were further floral morphology. However, until recently the flo-
elaborated on by Lindley (1830-1840). Subse- morphology group of orchids has «
ral in this
quent
students of the group have generally erected rather poorly understood. The flowers of tribe -
smaller and smaller genera, a tendency that finally seae are very complicated and difficult to interp
culminated in the large number of small genera (Dressier, 1981). Individual species were studi
Boh^
upheld by Rolfe (1912-1913)
in the Flora Ca- in detail by Trimen (1864), Weale (1873),
autfoc^
pensis. This system, however, did not result in a (1882), and Marloth (1895), but these
phylogenetually sound V*
classification, as the core mainly concentrated on species of subtribe
e-
paraphyletic genera were comprehensive
retained, and some of and The
their pollination. first
the segregated genera were number of spec
polyphyletic groups
scription of the flowers of a large
Volume 81 Number 4 Under & Kurzweil 689
,
Phylogeny and Diseae
1994 Classification of
was that of Harry Bolus in his floristic accounts fundamental trees were averaged and used to cal-
1888, 1893-1896, 1911, 1913, 1918). culate a weighting for each character, on a scale
(Bolus,
Further morphological knowledge was contributed from to 10. Then the parsimony analysis was
The
the floristic and taxonomic studies of Schlechter rerun to locate the most parsimonious tree.
in
(1898, 1901) and Rolfe (1898, 1912-1913). The procedure was repeated until the cladogram sta-
To mono-
exhaustive study of Vogel (1959) on the floral bilized. test the support for the different
morphology of various species was frequently re- phyletic groups, and the confidence with which they
garded as providing the final explanation for the may be proposed, the data set was randomly sam-
odd flower structures in this group. However, due pled 100 times, and the analyses rerun (Felsen-
1985; Sanderson, 1989; Linder, 1991). For
to the lack of ontogenetic investigations certain stein,
structures were misinterpreted. Morphologically each random sample the consensus tree was cal-
significant genera were not dealt with and, con- culated from the complete set of shortest equal
sequently, several questions remained unaddressed. length trees located by using the "ie*" routine in
In the past five years there has been substantial Hennig86. This was necessary to locate a single
progress in the knowledge of the morphology and tree for each sample to determine the frequency
ontogeny of the flowers of the Diseae. Kurzweil occurrence of each component, a routine which is
PAUP
Version 3.1 (Swofford, 1993).
(1990) described the Disinae, Kurzweil et al. (1991) not explicit in
&
and Kurzweil (1991) the Coryciinae, Kurzweil These 100 consensus trees were then scanned, and
Under (1991) some of the Disperis species, and the frequency of occurrence of each of the com-
&
Under Kurzweil prep.) Brownleea. In ad- ponents of the most parsimonious tree determined.
(in
morphology Although procedure approximates the "boot-
dition, Kurzweil (1989) described the this
of Huttonaea in great detail. Further sources of strap" methods of Felsenstein (1985), as imple-
&
information have been investigated: Chesselet mented by Swofford (1993), it differs in that the
Under (1993) studied the pollinium ultrastructure components of a selected topology are tested di-
and Chesselet (1989) reported on the leaf anatomy rectly, rather than indirectly, by the calculation of
of the Disinae and Coryciinae. We have extensive a 50% majority rule consensus tree from the set
do
sampled data Although these analyses
unpublished data for the Satyriinae. There are, of sets.
however, several structures that have not yet been not produce a valid statistical test of the confidence
1991; Werdelin,
cladogram (Linder,
adequately investigated. These include the chro- limits for the
mosome complement and the anatomy of the root- 1989), they do give a rough indication of the
stem support implicit in the data set used for each node.
tuberoids.
by Linder (1991)
The The methods used are described
available data suggest that a careful recon-
and Sanderson (1989).
sideration of the suprageneric classification of the
some
The coding of variable taxa poses prob-
tribe Diseae is required. In this study a cladistic
analysis of on which lems. Some of these problems may be due to the
all available data presented,
is
monophyletic, and so
a sound group terminal groups not being
phylogenetic classification for the
can be incorporating more variation than they should.
based.
genera have been tested
However, most of the
monophyly above) and where
(see
for their
critically
Methods
problem clearly delimited
there was doubt the is
genus broken
or the
Morphological, anatomical, and palynological (such as in the Disinae), is
Where
Pachites).
data were and components (such as in
collected from various publications, into its
two ways
there are
•n critical cases new observations were made from monophyletic taxa are variable,
the ancestral condition
tne herbarium and pickled collections held at the of coding the variation. If
been determined by a cladistic
"°lus Herbarium, University of Cape Town. for the genus has
Brownleea (Linder
Vouchers are given in the figure captions. These analysis of its species such as in
& Coryciinae sensu
data were then studied comparatively, scored for Kurzweil, in prep.) or in the
condition
tne genera, and a maximum parsimony analysis stricto (Kurzweil et al., 1991), this is
we
because are in-
Performed, using the "ie*" routine in the Hennig86 coded for the terminal taxon,
ancestor
Harris, character description of the
1988) cladistic analysis software package. terested in the
Where detailed infor-
ne data were outgrouped to a set of genera be- of the terminal unit. this
coded as
gging character
mation not available, the is
to the Orchideae, which differ in the pos- is
which
Session unknown the genus. Characters for
of a spurred In order to locate a single (?) for
lip.
m determined
could not be
°re resolved tree, successive weighting was ap- the evolutionary polarity
occur a
,,ied (Farris, 1969; Carpenter, 1988). The indi- by outgroup comparison l>ecause they in
l
which ontogenetic
vidual character consistency indices for the three small subset of the taxa, but for
Annals of the
690
Garden
Missouri Botanical
wmkwSh
scarified
FIGURES 1-4. Leaf anatomy of the Diseae. Scale bar: 50 jun.— 1. Disa oreophila H. Bolus; note large
—
& margin and small
caps on the vascular bundles. 2. Ceratandra atrata (L.) T. Durand Schinz; note bristle on leaf
—
between
sclerenchyma caps associated with the vascular bundles. 3. Disa pillansii L. Bolus; note the differences
alatum
the adaxial (on the left side) and abaxial epidermis, and the well-developed palisade layer.— 4. Pterygodium
=
Chessele
(Thunb.) Swartz, with the two epidermises similar, and without a mesophyll palisade. Vouchers (PC P. ,
=
L H. P. Under). 1: L 3663, 2. PC 26, 3. PC 22, 4. L. 4747.
data were available, were coded in taxa where the 1 98 1 c) in which the tubers may be lost, and the
these
character is missing to reflect the polarity inferred plants propagate by vegetative stolons. In
from aboveground leafy
the ontogenetic data. In several cases a char- species there often a perennial
is
may vascular-
acter be present in the majority of the species, cover. Although there variation in the
is
e
but absent in a few. Where these species are known ization of the root-stem tuberoids (pers. obs.), t
to be closely related to species with the character, homologies and structure of the root "st
basic ^!
understood
this variation was, as suggested by Stevens (1991), tuberoids are present inadequately
at
also
ignored. and the database is
to interpret the variation,
too incomplete.
still
i
Morphology was surve
The leaf anatomy of the Diseae >.
*-
prepJ-
by Chesselet (1989) and Kurzweil (in
vegetative morphology
i. "
may have very dlffere
though individual species
There appear to
is little variation in the vegetative mor- anatomies 1-4), these
leaf (Figs.
pa e
phology
in the tribe. In Ceratandra the perennat- homoplasious, and there no consistent
is
Herscheliant
ing organs are swollen roots, while in the remaining across the Some genera, like
tribe.
genera they are testicular root-stem tuberoids. The or Ceratandra, have distinctive leaf anatomieS'
This
only exceptions are some species Disa combine genera.
in (Linder, there are no features that
—
Disa
Figures 5-10. Habit and inflorescence structure of va_rnioouuss ssppeecciieess iinn trhnee tirriiboee.. Soccamlce buaar^s.: 5- cm- 5. ^
^
rornutd — sp •se.
(L.) Sw.; note robust many-flowered inflorescence
infloresence. 6. Huttonaea fimbriata Rchb. f., •
--««'*•"
leaves broad.- 7. Brownleea macroceras Sond., inflorescence of 1-2 flowers.- 8". C"eratand'ra grandiflara
relator
niany-flowered inflorescence contracted into an almost capitate head.— Pterygodiiuumm lleeuuccaanntthhuummHH.. tBtooliuuss^iic.
9.
(HK
sparse inflorescence.— 10. Satyrium candidum Sources
Lindl., robust, many-flowered inflorescence.
kurzweil). UK UK HK HK HK
5: ,.„., 6: 1599. 7: 1576, 8: 1226, 9: 1641, 10: Jackson s.n.
Number 4 Under &
Volume 81, Kurzweil 691
1994 Phylogeny and Classification of Diseae
692 Annals of the
Garden
Missouri Botanical
may not apply in the case of the sclerified leaves petals, are apiculate (Fig. 1 2). These apicules de-
of Herschelianthe, but the relationship with Disa velop very early in the ontogeny of these parts,
may
not clear, and similar leaves occur in some sec- and in some species be very well developed
is
tions of Disa (Fig. 1). The occurrence of hyster- (e.g., Disa telipogonis Reichb. f.), although in
anthy may be related to the anatomy and texture others they may be obscure (e.g., most species in
may
of the leaves and floral bracts, but this variation Monadenia). These apicules be remnants of
also restricted to within the Disinae, and cannot the unifacial tip of the general monocotyledon leaf
is
and
be properly interpreted until the phylogeny within structure, consisting of a unifacial tip bifacial
&
Weber,
this subtribe better understood (Linder Kurz- sheath (Kaplan, 1975; 1980; Rudall,
is
weil, 1990). 1990), with the blade developed from either or
both of them. Vogel (1959) interpreted the sepals
as being homologous to the bifacial sheath and the
INFLORESCENCES
II.
How-
unifacial tips the remnants of the leaf blades.
The
inflorescences are simple racemes, which
ever, such apicules are absent in the rest of the
vary from many- to single-flowered (Figs. 5-10). Diseae, but occur sporadically in many diverse
However, in most genera some species have nu-
orchid groups. Their polarization therefore dif-
is
merous which makes
flowers, the polarization of
as theoretically they would be primitive fea-
ficult,
this character difficult. It appears likely that a tures, but outgroup comparison to the Orchideae
many-leaved, many-flowered
plant (e.g., Fig. 5) is indicates that they are synapomorphic for the Disi-
the plesiomorphic condition, and, as this occurs in nae
virtually all genera, this does not provide any phy- The lateral sepals are generally unspecialized
logenetic information above the generic level (see 1-22). In some
ligulate to ovate structures (Figs. 1
also the discussion on this character Kurzweil autapomorphic
in genera they contain important
et al., 1991). groups within
characters, or characters that delimit
have short
the genera. In Disperis the lateral sepals
SEPALS
III.
Corycium they
conical spurs (Fig. 19), while in
The involvement of the sepals in the attractive are often papery, and may be partially fused (Fig-
may
organs of the flower contain some phylogenetic 17).
without
information. In the Disinae and Satyrium the The dorsal sepal unspecialized (e.g.,
lat- is
20-
eral sepals are brightly colored, and may be the peculiar modifications) in the Satyriinae (Figs.
Coryciinae
largest and most brightly colored floral organs (Figs. 22), Huttonaea (Figs. 13, 14), and the
other
the
11, 12, 15, 20, 21), while in the Coryciinae sensu sensu stricto (Figs. 16-18), but differs in
some
stricto (Coryciinae excluding Disperis, see Kurz- genera. In the Disinae (Figs. 11, 12) and in
A
galeate.
weil et al., 1991) they are green and generally species of Disperis the dorsal sepal is
diagnos ic
insignificant (Figs. 16, 17, 18). The modification spurred dorsal sepal supposed to be
is
without
of the sepals to become part of the attraction system for the Disinae, but there are some species
to
similar
of the flowers is difficult to quantify, especially when spurs, although these are usually very
& Kurz-
the flowers are green. Green flowers, in which the spurred species (Linder, 1981c, e; Linder
spurs
the
sepals differ in texture from the bracts, are also weil, 990). therefore assumed that
1 It is
the
genera of
considered
modified. were and the
lost secondarily, all
sepa
In Disinae the sepals, and sometimes even the Disinae are coded as having spurred dorsal »
—
FlCURES 11-22. Flowers of various Diseae. Scale bars: 5 mm. 11. Disa erubescens Rendle; note the larg>
sepals and the narrowly linear lip.— 12. Herschelianthe graminifolia (Ker Gawl. ex Spreng.) Rauschert; note
broad, ovate and fimbriate F
lip the large galeate dorsal sepal.— 13. Huttonaea grandiflora (Schltr.) Rolfe, with a
Son
and petals.— Huttonaea macroceras ••
14. pulchra Harv., with spathulate fimbriate petals.— 15. Brownleea
—
0*0*
with the large lateral sepals and the petals adnate to the dorsal sepal to form the galea. 16. Cer—atandra
& C
Durand
(mL.) T. Schinz, with the lateral sepals arching forward and the large hornlike anther thecae. 17. °L^\
*
(Ihu
spurn (Thunb.) Sw.; note the large galea constructed Pterygodium inversum )
largely of the petals.— 18.
Sw.
with a large galea constructed largely from the petals; note that in this species the flowers are not resupimna*te-^
—
Ihspersis paludosa
19. Harv.; note the spurred lateral sepals. 20. Satyrium erectum Lindl., with the lip ''
mto
a two-spurred galea, and the petals and sepals forming the landing platform at the entrance to t—he galea.
I™
batyrmm
odorum
Son,!., showing 22.
the entrance to the galeate lip, with the upper margin recurved. *,
adpressa = HK HK 1069,1*. '
Lindl.; note the very simple (HK
perianth. Sources H. 1404, 12:
Kurzweil). II:
HK
HK
1986,
1591, 14: 1623, 15: 1576, 16: Jackson ,.«., 17: Jackson s.n., 18: Darling Wild Flower Show
Drewe HK
s.n., 20: Jackson s.n., 21: 852, 22: Burger
s.n.
Number Under & Kurzweil 693
4
Volume 81
,
Phylogeny and Classification of Diseae
1994
694
Annals
of the
Missouri Botanical Garden
following the guidelines suggested by Stevens
dorsal sepal to the galea, especially
in Disperis.
In
(1991). However, the situation more complex some
is in species the petals are simple
lorate to
linear
Disperis, where only a minority of the species bear
structures, with the dorsal sepal forming
the bulk
dorsal sepal spurs. As there is as yet no general of the galea (Fig. 19), while in other species
the
cladogram
available for the genus, cannot be
it dorsal sepal is a simple, linear structure,
essentially
inferred whether the presence or absence of spurs only forming the keel of the galea, while the
petals
is ancestral, nor can the frequency of occurrence form the bulk of the hood
(Figs. 17,
18).
argument
be used
in this case, because not In the Disinae and Brownleea
it is the base of the
clear whether these spurs were
lost secondarily or petals is fused to the gynostemium. This fusion
gained independently from the spurs may
in the Disinae. be insignificant, or in Disa sect. Aconitoideae
Disperis has therefore been coded unknown may
as
for be in the form of a prominent ridge. Kurzweil
this character. In the rest of the Coryciinae, the
(1990) has substantiated Schlechter's (1901)
opin-
dorsal sepal is not generally galeate and, although
ion that the fusion keel is derived, at least partially,
may
be concave and form
it a galea in combination from The
staminodes. presence of various lobes on
with the
petals, it is usually the smallest of the the petals useful and
is at specific, sectional, pos-
organs may
involved. It be that once a deeply some
sibly in cases generic level, but presence
its
concave
or galeate dorsal sepal evolves, the
step is rather variable in most genera, making of
it little
toward
a saccate or spurred
structure
is relatively use for suprageneric analysis. Basal anterior lobes
small, and this may account
for the parallel evo- have been used
to define the sections in the large
lution of dorsal sepal spurs
in the Disinae and
in genus Disa (Under, 1981c), and apically bilobed
Disperis. Comparison
with the cladogram
would
petals occur in the majority of the species of Disa
also indicate a
parallel evolution Brownleea, &
in
in sect. Micranthae (Under, 198 Under Kurz-
If;
which
the dorsal sepal is a slender organ. This
is weil, 1990).
an
exception
to the above
theory.
It is evident that Huttonaea has very peculiar petals, which are
spurred
dorsal sepals evolved
several times
in the clawed, with a saccate blade and a fimbriate margin
Diseae, and
as this character has
generally been
The appear
(Figs. 13, 14). apices of the fimbriae
stressed in the subtribal may
classifications, have
it to be glandular (Kurzweil, 1989).
contributed
to the persistent
misclassification of Biologically, the petals in the Disinae appear to
Brownleea.
function to direct the pollinator into the dorsal sepal
spur, in the Coryciinae they form the galea, and
IV. PETALS in the Satyriinae they form part of the landing
The Hut-
platform.
role of the fimbriate petals in
The
petals are very
variable
in the
tribe (Figs. tonaea is not clear, and possible that the glands
it is
1 1-22) and have been found
useful at the infra- offer a reward
for the pollinator.
generic
level in the Disinae (Under,
1981a-e- Un-
Frequently formation of the
associated with this
&
der
Kurzweil,
1 990). In the Coryciinae' and presence of
petals plus dorsal sepal galea the
is
Brownleea
the
petals are adnate
The
(postgenitaUy
extraordinarily strongly developed petal nerves.
fused)
to the
dorsal sepal, and the three
structures degree of development of such "petal nerves" is
combine
form
to the galea
(Figs. 15-19).
This is variable, and they are missing in many species.
also found a
to lesser extent
in the Orchideae However, have been
although such "petal nerves"
especially
in Cynorkis. There
is extensive variation recorded subfamilies oi
in various genera of other
in the degree
of
contribution
of the petals and the the orchids, they have a restricted distribution in
^T
™T
°^ Cut
surfaces are indicate" bv ^tctnfT ? in the Diseae showin6 th^e gynostemium and Up-
= '
Scale bars: B, D E G mm ?C F-T^ "**> anther s = «&..^1 = hP and la = lip appendage
f '
1 ^£ B~Pa^ckU^es H note
bodkinii Bolus.- Gynostemium and up;
the long column som^' .Tj A.
part and ^T^, ^t^
iumToLs 'tk tf~u-um «*"*
^C
two °
f the
and
Gynostemium and a Tfth "TW** ^°/ the r°SteUum lobes C D Satyrium erectum Swartz.^.
half-section %***** ' ' -
^"-1
showing one -D. gynosterruu*
apex; note of the two spurs. Details of the
the
flaplike
It
Lf
showing the verticaIsca M < > N.E. Br., gynostemium with the horizontal lipL, ^
wrTere the n "" - -J-
*******
showing the massive ^ to the gy^stemium. F. Pterygodium acutifohum
erect Ik n A
6yn° mium carr^
Ste
to the sides of theTp G BroZZ with the anthers widely sepaJfd, and the viscidia
c ^^ «*
a narrow erect lin/in o^t" ^""T u^" Sh°Win& the"KP ^broadly fused to the base of the stigma,
front ^
W3L i££ /si" ? & D
?*
A B Bur **
E. Under I6TO F urces *°r '
' ' '
Number 4 Under &
Volume 81, Kurzweil 695
Phylogeny and
1994 Classification of Diseae
i
O
696 Annals of the
Garden
Missouri Botanical
the Diseae, and may therefore be informative de- secondary losses, as the species concerned
are
spite their occasional absence in some of the groups clearly related to species with bi-spurred lips. In
in which they occur. The polarization of the char- Pachites the lip is very simple, as in the Disinae,
acter on the tree is not unequivocal, as there have while in Huttonaea it is broad and fimbriate. In
been three parallel gains in this character, as com- Brownleea the lip has a broad base which is fused
pared to four losses. The polarization has therefore to the base of the gynostemium, and a tiny linear
been determined by the distribution of the char- blade which is erect in front of the rostellum (Fig.
acter in the outgroup. 23G).
The
lip of the Coryciinae is truly complex. The
blade variable shape, ranging from
is in linear to
V. LIP
triangular to three-lobed and from medium-sized
The lip is the most complex perianth member to large. In Evotella and Ceratandra the lip blade
most makes
in orchid groups. It usually the orchid characteristically spathulate and anchor-shaped
is
flower zygomorphic and often has complex lobes (Kurzweil et al., 1 99 ). The base of the lip is almost
1
and excrescences. Consequently has been sug- always fused to the base of the gynostemium. The
it
gested (e.g., Darwin, 1888) that the lips are mor- lip also bears an appendage that is found in the
phogenetically complex organs, consisting of an same position as the median adaxial stamen A3
inner tepal and the staminodes. This hypothesis is (which lost in orchids) (Fig. 23F), and this might
is
no longer entertained because of the lack of sup- suggest a derivation from such a staminode (Pntzer,
porting evidence (Dressier, 1981). Although the 889). However, ontogenetic evidence obtained in
1
lip in the Diseae is enormously variable and often various Coryciinae clearly suggests that the lip is
extraordinarily complex, it is very different from of the same nature as the petals (Kurzweil, 1991).
the "typical" orchid lip, in that it rarely shows The peculiar appendage of the Coryciinae is
lip
three lobes, rarely has lip-calli, and never has a initiated late in the ontogeny. Apparently, the lip
median
single spur (Fig. 23). appendage of the Coryciinae merely an out-
is
The
orientation of the numerous other
lip is variable. In the growth of the as also found in
lip
Orchideae and some
in groups of the Diseae the appendage probably primitively
orchids. This
is
&
lip is orthotropous: it continues, at least at the base, bilobed (Kurzweil et 1991; Kurzweil Under,
al.,
same
in the direction as the axis of the flower. This 1991), but in many groups there is little trace of
is particularly evident in the Orchideae with median the bilobed origin, and in Corycium it forms a
spurs on the lips, where the spur is parallel to the massive shield over the anther and rostellum (Kurz-
ovary, and
essentially in line with the blade. In
lip weil et al., 1991).
the Satyriinae the lip is also orthotropous (Fig. The function of the in the pollination biology
lip
23C). In the Coryciinae and Brownleea Satyrium and Sa-
the lip is is, like the petals, complex. In
also in line with the axis, at least at the base, where tyridium forms the hood and the spurs bearing
it
it is generally fused to the gynostemium (Fig. 23F, the nectar; in the Disinae forms part of the
it
G). In the Disinae excluding Schizodium, however, landing platform together with the lateral sepals,
the lip is reflexed at the base, so that it is held at and in the Coryciinae usually bears the ou-bearing
it
right angles to the axis of the flower (Fig. 23E). bees (Steiner, 19» )
attractant for the oil-gathering
A
similar situation found Huttonaea
is in (Figs.
1 3, 1 4). In the Disinae the lip a simple structure,
is
GYNOSTEMIUM
VI.
without any
outgrowths,
usually without and
lobing,
not fused any group of
to other organs
(Fig. 1 1). It is usually The anther basally reflexed in this
is
a linear to lorate organ Disa occurs very late
(e.g., uniflora), al- orchids (Fig. 23). This reflection
though may "°weV
be
it rarely ovate (Disa ferruginea in the ontogeny, directly before anthesis.
^!
(Thunb.)
Sw., Herschelianthe retlex
graminifolia (Ker of the
there are exceptions to the rule
Gawl. ex Spreng.) Rauschert, and PterYg°-
Fig. 12), variously anther. In Disa sect. Micranthae
lacerated (Herschelianthe barbata (L.f.) N.C. An- dium Ommatodium the anther is alwayscrec .
sect.
thony), clawed u
(Herschelianthe
multifida (Lindl.) and there no evidence of any reflection
is
^
Rauschert), lobed (Herschelianthe sect
spathulata Pterygodium
(L. f.) ontogeny. In the case of
jW
Rauschert), or divided into a hypochile, mesochile, matodium, (1991) postulated
Kurzweil
et
al.
and
epichile (Schizodium). In Satyrium an
(Figs. 20, the erect anther derived from a reflexed
is
21) and Satyridium ana
the lip is galeate and has two and was supported by their cladistic >-
this
spurs. These
spurs are obsolete or highly reduced reflexed,
In Brownleea the anther basally
is
in a few species, but these are almost impre
certainly the apical portion erect, giving the
is