Labellum micromorphology in theOphrys bertolonii agg. and some related taxa (Orchidaceae)

Micromorphology and distribution of trichomes in six taxa of theOphrys bertolonii aggregate (O. bertolonii, O. bertoloniiformis, O. benacensis, O. aurelia, O. drumana, O. catalaunica) are described. A fairly good homogeneity between all the taxa, with a moderate degree of variability even within the same taxon, has been observed. Comparison of these characters with those ofO. promontorii andO. garganica corroborates the inclusion of the former species into theO. sphegodes aggregate. Trichome analysis of a hybrid is exemplified byO. ×chiesesica (O. drumana ×O. fuciflora).     

Hybriden und hybridogene Sippen ausOphrys bertolonii undO. atrata (Orchidaceae)

Flower polymorphism in 15 ItalianOphrys populations (N = 282) was analysed in detail. Statistical and graphical evaluation of data demonstrates morphological relationships and amount of hybrid character coherence.O. bertolonii s. str. andO. atrata are stable parental taxa, but occasionally form hybrids and hybrid swarms. Much evidence suggests that it was through such homogamic hybridization, involving these and other species ofOphrys, that the stabilized taxaO. bertoloniiformis andO. promontorii (ecologically different, but sympatric with the parents on Gargano), andO. benacensis (geographically separated from the parents in the Insubric region) originated. These differentiation-hybridization cycles are linked to the break-down and new establishment of incomplete prezygotic crossing barriers (e.g. different flower biology, flowering time, habitat preference).

     

Biometrische Untersuchungen an Populationen vonOphrys cornuta,O. holosericea und ihren Hybriden (Orchidaceae)

Population variability ofOphrys holosericea (Burm. f.)Greut. subsp.holosericea (=O. fuciflora Crantz subsp.fuciflora) from near Vienna (Austria), and of subsp.maxima (Fleischm.)Greut. andO. cornuta Steven with intermediates from the Dalmatian island Hvar (Yugoslavia) was analysed and illustrated by scatter diagrams. A hybrid origin of these intermediates is suggested. Aspects of hybridization betweenO. holosericea agg. andO. scolopax agg. are discussed.

     

Biometrical analysis on populations ofOrchis israelitica,O. caspia,and their hybrids (Orchidaceae)

The population variability ofOrchis israelitica, O. caspia, and their intermediates, from two localities in Israel, was analyzed and illustrated by scatter diagram and hybrid index. It is suggested that the hybrids are a result of introgression and are closer toO. caspia. Aspects of isolating barriers between these two species are discussed.     

A new species ofLiparis (Orchidaceae) from India

Liparis indiraii spec. nova from India is close toL. alata A. Rich. andL. atropurpurea Lindl.     

Gene variation and gene flow inOrchis morio (Orchidaceae) from Italy

Data are presented on genetic variation at 27 enzyme loci of the Green-Winged orchid,Orchis morio, in 18 population samples from Italy. The existence in Italy of two subspecies, i.e. subspp.morio andpicta, is not supported by allozyme data. No genetic heterogeneity was found betweenmorio-like andpicta-like samples and specimens. Moreover, morphological transition between the two forms was observed in different Italian populations. The parameters of genetic variability estimated forO. morio populations are consistent with those found among monocotyledon plants, and among those outcrossing, animal-pollinated and with wind-dispersed seeds. Genetic diversity of ItalianO. morio is mostly within populations. Correspondingly, low values of interpopulational genetic distance were found. This appears to be due to high levels of gene flow, which were estimated with different methods. The lack ofO. longicornu from Italian samples, as well as of any hybrid withO. morio (F₁, backcrossed or recombinant individuals) is demonstrated on the basis of genetic data. It is concluded that recurrent reports ofO. longicornu from Italy are due to confusion withO. morio or with otherOrchis species.     

Orchis prisca (Orchidaceae), eine neue Art aus Kreta

Orchis prisca Hautzinger is described as a new diploid species from Crete, related toO. patens andO. spitzelii.

     

Seed morphology in Southern AfricanOrchidoideae (Orchidaceae)

The seed morphology of 151 species of Southern AfricanOrchidoideae (Orchideae andDiseae; sensuDressler 1981) was studied by means of scanning electron microscopy. Two different seed types were found. (1) In the majority of species the seeds are minute and fusiform. The seed coat is made up of comparatively few concave and elongate testa cells with straight or slightly undulate and generally unthickened anticlinal cell walls. The seed type was here termed Satyrium-type. While most species are very similar in the ornamentation of the periclinal walls of their seed coat, considerable variation was found inHolothrix where two distinct groups can be recognized in this respect. (2) A remarkably different seed type was observed inDisa uniflora and three apparently closely related species (Disa uniflora-type), where large balloon-like seeds occur. Their seed coat consists of convex cells with undulate anticlinal walls. It is suggested that this seed type is a derived condition and has evolved in adaptation to the specialized habitat alongside streams. The possibility of hydrochory in these four species is briefly discussed.     

New and noteworthyHabenaria spp. (Orchidaceae) from New Guinea and adjacent islands

5 new taxa ofHabenaria, namelyH. bougainvillae, H. elongata R. Br. var.leptophylla, H. ensigera, H. rechingeri andH. trichoglossa, are described and illustrated, with reference to affinities to related Australian and Indo-malayan species. The occurrence in New Guinea of severalHabenaria spp. typical for a savanna-like vegetation, led to look more thoroughly at these taxa:H. elongata R. Br. andH. ochroleuca R. Br., considered so far to be endemic in Northern Australia, andH. khasiana Hook. f., hitherto only known from southeastern Asia.Studies in the subtribeHabenariinae Bentham (Orchidaceae), 2.—Part 1: Candollea34, 357 (1979).Dedicated to Hofrat Prof. DrKarl Heinz Rechinger on the occasion of his 80th birthday. — On April 30, in the year 1927, the author and his brotherOtto Renz metKarl Heinz Rechinger on a small steam-boat in a stormy Aegaen Sea, travelling from Piraeus to the Northern Sporades Islands:Karl Heinz with destination to Chelidromia, the author andO. Renz to Skopelos. By this lucky chance a lasting friendship began.     

Ophrys helenae (Orchidaceae), eine lange verkannte Sippe der Balkanhalbinsel

Population analyses, scatter diagrams and field observations demonstrate thatOphrys helenae is morphologically (and ecologically) well separated from the partly sympatricO. mammosa andO. ferrumequinum in N. Greece. Hybrids with the distantly relatedO. mammosa are very rare.

     

Bird pollination in South African species ofSatyrium (Orchidaceae)

Field observations showed that three South African orchid species,Satyrium carneum, S. coriifolium andS. princeps, are pollinated by sunbirds. Foraging sunbirds insert their bills into the labellum chamber of the flowers and suck nectar from the labellum spurs with their tongues. The column overarches the entrance to the labellum and pollinaria become affixed to the upper mandible of the bill. Birds often attempt to remove pollinaria by rubbing their bills against a branch, but are mostly unsuccessful due to the large plate-like viscidia which attach the pollinaria very firmly to the bill. Other modifications for bird pollination in theseSatyrium species may include the red, carmine or orange colour of the flowers, sturdy inflorescence stems used for perching and large amounts of dilute nectar in the spurs. EachSatyrium species was pollinated by several species of sunbird, and despite some differences in flowering time, occasional hybrids occur at a site whereS. carneum andS. coriifolium share the same sunbird pollinators.     

Insect pollination and floral mechanisms in South African species ofSatyrium (Orchidaceae)

The morphologically diverse flowers in the genusSatyrium reflect adaptations to a wide range of pollinators. Several recently discovered pollination systems inSatyrium are described and illustrated here; these include pollination by solitary bees, carrion flies, butterflies and moths. Two basic types of floral mechanism are recognised inSatyrium: (1) Species pollinated by lepidoptera and birds have long floral spurs and plate-like viscidia seated in lateral rostellum notches; these viscidia become attached to the proboscis or bill of the pollinator. (2) Species pollinated by flies and bees have relatively short floral spurs and globose viscidia seated in terminal rostellum notches; these viscidia become attached to the face, thorax or eyes of the pollinator.     

Pollination ofOphrys (Orchidaceae) in Cyprus

In the southern part of Cyprus the pollinator —Ophrys (Orchidaceae) relationships and its specifity have been investigated from the end of February until the middle of March 1986. 12Ophrys spp. were found. To date, only a single pollinator reference has been reported from this island. We found the following pollinators:Melecta tuberculata (Ophrys kotschyi),Eucera dimidiata (Ophrys flavomarginata),Eucera gaullei (Ophrys umbilicata),Eucera paulusi (Ophrys bornmuelleri),Anthophora erschowi (Ophrys elegans),Andrena torda (Ophrys sicula =O. lutea subsp.minor),Andrena cinereophila (Ophrys fusca, small-flowered),Andrena flavipes (Ophrys israelitica),Andrena morio (Ophrys iricolor andOphrys transhyrcana),Andrena bimaculata (Ophrys sphegodes aggr., probably formerly confused withO. transhyrcana). Most interestingly, it could be verified thatO. flavomarginata/O. umbilicata, O. bornmuelleri/O. levantina andO. transhyrcana/O. sphegodes aggr. (possiblyO. sintenisii) are different biospecies. This is a result of genetic isolation due to varying pollinators, and of differences in flower morphology.     

Karyological differentiation and speciation in C. MediterraneanAnacamptis (Orchidaceae)

Anacamptis pyramidalis is a variable and wide-spread European-Mediterranean taxon. Beside a dominant cytotype with 2n = 36 it includes cytotypes with 2n = 54 and 63 in northern Tuscany (and the Eastern Pyrenees) and one with 2n = 72 on Malta. In contrast,A. urvilleana, formerly often misidentified and included inA. pyramidalis, is a monomorphic and distinct species, endemic to the Maltese Islands. It has 2n = 36, can be clearly separated by morphological and anatomical features and is isolated from partly sympatric populations ofA. pyramidalis with 2n = 72 by differences in chromosome number, flowering time and habitat preference.     

Molecular evidence for hybridization ofIlex x wandoensis (Aquifoliaceae) by RAPD analysis

Based on the presence of intermediate morphological characters, such as serrated leaf margins and flower structures,Ilex x wandoensis was initially described as a putative natural hybrid betweenI. cornuta andI. Integra, and was formally described as a new hybrid species,I. x wandoensis C. F. Mill., and M. Kim. However, using molecular markers generated via random amplified polymorphic DNA (RAPD), we have now discovered hybridization in populations of theI. x wandoensis complex collected from Wando and Jeju Islands, Korea. Marker bands of the putative parent taxa also were found in some populations ofI. x wandoensis, confirming its hybrid origin. Morphological variability within and among those populations was confirmed by model-based clustering methods, using multilocus genotype data. Phenograms generated from RAPD bands indicated that some accessions ofI. x wandoensis clustered with one of the parental species. This implied the occurrence of hybridization and recurring backcrosses of the hybrid to both parents, resulting in various hybrid derivatives because of the segregation and recombination of traits.Ilex x wandoensis was more closely related toI. cornuta than toI. integra suggesting that it backcrossed more with the former than with the latter.     

An embryological study ofPlatanthera bifolia (Orchidaceae)

Flowers ofPlatanthera bifolia were hand-pollinated and fixed in FPA₅₀ after 2, 5, 7, 14, and 21 days. Ovules, made transparent in Herr's clearing fluid, were investigated using confocal scanning laser microscopy. Pollination initiates the megasporogenesis. Two days after pollination dyads are frequent. Three days later most embryo sacs contain two nuclei. Seven days after pollination the embryo sacs are 4–8-nucleate and some are organized, and a week later all embryo sacs are organized and fertilization takes place. The embryo sac development follows thePolygonum type. Twenty-one days after pollination the egg nuclei have been fertilized and the embryo sacs contain 2- to many-celled embryos. A suspensor is formed during early stages of embryo development but degenerates later. Fertilization of the central nucleus does not lead to endosperm development.     

Floral mimesis inThelymitra nuda (Orchidaceae)

Insect pollination occurred inThelymitra nuda R. Br. on sunny days when the ambient temperature exceeded 20 °C. The flower buds on a raceme opened subsynchronously displaying the brightly-colored, actinomorphic perianth and exposed the contrastingly-colored, scented and ornamented column. InT. nuda the staminodes and the filament of the fertile stamen are fused to one another producing an inflated hood over the anther. This staminodal hood is terminated in two non-ornamental, but brightly-colored, central lobes and two terete lateral lobes bearing approximately 400 white trichomes. Each trichome bears a double chain of 30–40 spherical, rugulose cells. Female bees, in the genusLasioglossum (Halictidae), were observed to land directly on the hood and curled their bodies around the four lobed tip of the staminodal complex. The bees attempted to forage on the lobes as if they were collecting pollen from fertile, poricidal stamens. These bees applied thoracic vibration to the yellowish central lobes and actively scraped the trichome clusters (Pseudopollen) with their forelegs. Bees carried the pollinaria ofT. nuda dorsally on their abdomens. Abdominal contact with the rostellum appeared to occur when the female bee disengaged herself from the staminodal hood. Observations made of bees on co-blooming flowers, and analyses of pollen loads collected by bees suggested that the orchid flower mimics the guild of blue-purple flowers that lack floral nectar but offer pollen in poricidal anthers. The models ofT. nuda are co-bloomingLiliaceae in the generaDichopogon andThysanotus. However, nectarless, buzz-pollinated flowers are also extensively distributed over the orchid’s range. More than 30% of the flowers in theT. nuda population had their pollinaria removed, suggesting a high capacity for cross-pollination in an orchid genus usually considered to be self-pollinated via mechanical autogamy. This study confirmed previous predictions that column modifications represented a trend towards pseudanthery.     

Interspecific hybridization in natural populations ofCyrtandra (Gesneriaceae) on the Hawaiian Islands: Evidence from RAPD markers

Interspecific hybridization among Hawaiian species ofCyrtandra (Gesneriaceae) was investigated using randomly amplified polymorphic DNA (RAPD) markers. Thirty-three different primers were used to investigate interspecific hybridization for 17 different putative hybrids based on morphological intermediacy and sympatry with putative parental species. RAPD data provided evidence for the hybrid origin of all putative hybrid taxa examined in this analysis. However, the patterns in the hybrid taxa were not found to be completely additive of the patterns found in the parental species. Markers missing in the hybrid taxa can be attributed to polymorphism in the populations of the parental species and the dominant nature of inheritance for RAPD markers. Unique markers found within hybrid taxa require further explanation but do not necessarily indicate that the taxa are not of hybrid origin. The implications suggest that these interspecific hybridization events had, and continue to have, an effect on the adaptive radiation and conservation biology ofCyrtandra.     

Observations of the floral biology ofPrasophyllum odoratum (Orchidaceae,Spiranthoideae)

Prasophyllum odoratum is a vernal, nectariferous, terrestrial orchid that flowers profusely six to eight months following cyclical fires that disrupt sclerophyll woodlands. The morphology of the column and pollinarium is indicative of taxa placed within the subfam.Spiranthoideae. The orientation of the pollinaria to the stigma appears to prevent mechanical self-pollination. Both cross- and self-pollination appear to be effected by insects that forage within the brightly-colored, scented, non-resupinate flowers. Ants and drosophilid flies remove nectar, but do not appear to transport pollinaria between flowers. The primary pollinators are polytrophic flies in the fam.Syrphidae and opportunistic male bees in the genusLeioproctus (Colletidae). Approximately 52% of the flowers on a raceme set seed. The comparatively short floral tube ofP. odoratum reflects the dependence of this species on short-tongued insects to effect successful dispersal of pollinaria.     

Vanda longitepala (Orchidaceae): a new species from Burma

Summary   Vanda longitepala, a new species of orchid from northern Burma is described and discussed.