Long-proboscid fly pollination of two orchids in the Cape Drakensberg mountains,South Africa

Large hovering flies with elongated nectar-feeding mouthparts play an important role in the pollination of South African plants. Here we describe and illustrate the pollination of two long-spurred orchids —Disa oreophilaH. Bolus subsp.erectaLinder andBrownleea macrocerasSond. — by the long-proboscid flyProsoeca ganglbaueriLichtwardt (Nemestrinidae).     

Pollination biology of annual and perennialLeonotis species (Lamiaceae)

The pollination syndromes ofLeonotis (Pers.)R. Br. are discussed. Ornithophily accounts for most of the nutlets set in perennialLeonotis species but in the annual species [L. nepetifolia (L.)R. Br.] autogamy prevails.Leonotis species are predominantly pollinated by a variety of sunbirds, although bees are also involved. Nectar is sucrose-dominant in perennial species but hexose-dominant in the annual.     

A reconsideration of the genusRabdosiella (Lamiaceae,Nepetoideae, Ocimeae)

The two generaPlectranthus andIsodon are compared and found to be very dissimilar.Isodon ist considered to be misplaced inOcimeae subtribePlectranthinae and apparently is more closely related to subtribeHyptidinae. The disjunct genusRabdosiella is compared to these two genera and regarded to be polyphyletic. The AfricanR. calycina (Benth.)Codd is returned toPlectranthus and calledP. calycinusBenth., while the AsianR. ternifolia (D. Don)Codd is placed inIsodon sect.Pyramidium and calledI. ternifolius (D. Don)Kudo.     

Pollination biology ofOpuntia polyacantha andOpuntia phaeacantha (Cactaceae) in southern Colorado

The phenology, compatibility system, and pollinator fauna ofOpuntia polyacanthaHaw. andO. phaeacanthaEngelm. in southern Colorado were studied and compared. The total blooming periods overlap, but the peak of blooming differs between the species withO. polyacantha blooming first and for longer. Neither species is apomictic,O. polyacantha is largely self-incompatible andO. phaeacantha is self-compatible but may not automatically fully self-pollinate. Examination of flowering structures showed that the former has larger flowers with more perianth parts and heavier (but fewer) anthers. Further the flowers of the allogamous species are visited by greater diversity (but similar abundance) of pollinators. Medium to large bees of the generaDiadasia, Lithurge, Melissodes, Bombus, Agapostemon andMegachile were found to be effective pollinators of the Opuntias studied. The two species were compared as to their floral attributes, breeding systems, and pollinators, and the possible role of competition for pollinators is discussed with respect to its role in their evolutionary paths.     

Differentiation patterns in the E. MediterraneanScutellaria rubicunda group (Lamiaceae)

Strict sterility barriers where found between theScutellaria populations on Sicily and the Greek populations. The material from Samos is separated by a strict sterility barrier from the other Greek populations. In contrast, the populations on mainland Greece and adjacent islands are all ± interfertile. Three species are recognized,S. rubicundaHornem., endemic to Sicily, andS. brevibracteata subsp.icarica, endemic to Samos and Ikaria. All other populations are referred toS. rupestris with eight subspecies, most of which are endemic to one island or to one mountain. Three new subspecies are described, viz. subsp.rechingeri and subsp.olympica, endemic to mt Vourinos and mt Olympus in North Greece, respectively, and subsp.caroli-henrici, native to the Malea peninsula of Peloponnisos. The phytogeographical connections and genetic differentiation within and between populations are discussed.Dedicated to Prof. DrK. H. Rechinger on the occasion of his 80th birthday.     

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 of four sympatric species ofAngelonia (Scrophulariaceae) by oil-collecting bees in NE. Brazil

The manner whereby the oil-producing bisaccate flowers ofAngelonia (Scrophulariaceae) are pollinated by female oil-collecting bees is reported for the first time. Observations were made in the Caatinga formation of Pernambuco, NE. Brazil, on four synchronopatric species. These differ in sizes and structural details of the corolla, level of flower exposition, and habitat preferences. All legitimate visitors wereCentris spp. (Anthophoridae):Angelonia hirta was mainly pollinated byC. fuscata andA. pubescens byC. hyptidis; A. bisaccata andA. hookeriana shared an unidentified species. Several exomalopsine, tetrapediine and meliponid bees exploit the flowers less descriminately for oil or pollen, respectively, without regularly contacting anthers and stigma. The flowers are protandrous, and are self-incompatible except those of the annualA. pubescens. After alighting, theCentris bees introduce their front legs simultaneously into each of the pouches and start alternate collecting movements to gather the oil from the trichome elaiophores. While doing so, they are forced by projections of the corolla floor to press their head under the anthers and stigma, whereby pollen is transferred with their frons or clypeus. On account of their collector type and behaviour,C. fuscata andC. spec. are not specialized toAngelonia but may equally exploit other nonrelated taxa for oil, whereasC. hyptidis exhibits oligolecty onA. pubescens. It possesses relatively elongate forelegs with padlike collectors suitable for sweeping the lipids from the scattered glandular hairs inside the divergent spurs of its host. It is the only species that also collects pollen (by buzzing) from the oil host.A. hirta and relatives, provided with dense elaiophore carpets, are, for their part, adapted to scrapingCentris species with typical oil collectors. Flower and bee phenologies, although largely dependent on the irregular rainfalls, are not always coincident.     

Pollination ofDianthus gratianopolitanus (Caryophyllaceae)

Pollination ofDianthus gratianopolitanus was studied in a population of the Swiss Jura mountains. Pollinators of this plant species are reported here for the first time. The flowers were not only visited by butterflies as postulated in the literature, but also by diurnal hawkmoths (Macroglossum stellatarum) and by diurnal and nocturnal noctuid moths. — Nectar is sucrose-dominant, the sugar concentration is moderate but the amino acid concentration is high. Nectar characteristics correspond well with the syndrome ofLepidoptera-pollinated flowers. — Field observations and flower characters (colour, range of the calyx length) suggest thatDianthus gratianopolitanus is an intermediate species in the transition of butterfly to moth pollination. — Lack of reproductive success inDianthus gratianopolitanus can not be attributed to lack of suitable pollinators.     

A New Species ofSalvia (Lamiaceae) from the Sierra de Los Tuxtlas,Mexico

Salvia tuxtlensis, sp. n., is immediately recognized by its semipersistent bracts and yellow flowers. Its affinities are not clear. It is endemic to the Soteapan area in the Sierra de Los Tuxtlas, in Veracruz, Mexico.     

Pollination by deceit and floral mimesis inThelymitra antennifera (Orchidaceae)

Thelymitra antennifera is found to be a general mimic of the search image of other co-blooming yellow or cream-flowered species including members of the following genera:Hibbertia, Goodenia and, to a lesser extent,Helichrysum, Pimelia andStackhousia. The most common pollinators areLasioglossum (Chilalictus) spec. and the introducedSyrphus damaster (hover fly) as well as a solitary wasp,Eurys spec.—T. antennifera acts by deceit, involving opticals (yellow colour and pollen imitation) as well as olfactory (sweet odour) signals. Capsule production is low and density dependent, a situation demonstrated in other species which have evolved pollination syndromes involving deceitful mimicry.     

Floral divergence and convergence in the genusPelargonium (Geraniaceae) in southern Africa: Ecological and evolutionary considerations

Based on field observations and a survey of the available literature, the functional and evolutionary significance of floral characters ofPelargonium is investigated in relation to a recent infrageneric re-classification. Most of the 208Pelargonium taxa (recognized as species, subspecies or varieties) involved show bee and long-proboscid hovering fly pollination syndromes (about 60% and 25%, respectively), only 7% of the taxa are pollinated by butterflies, some 2 to 4% by hawkmoths and presumably 1% by birds. The heterogeneity ofPelargonium in terms of structural blossom types and pollination syndromes indicates an independent and repeated evolution of convergent flower morphs in the genus and even in sections.     

A revision of <Emphasis Type="Italic">Anisochilus</Emphasis> Wall. ex Benth. (Lamiaceae)

Summary  Sixteen species of Anisochilus are reviewed. Full synonymy, information about types, distributions, and a key to species are given. The type of the little known A. adenanthus Dalzell has been found and the widely used A. verticillatus is a synonym. A. sericeus and A. dysophylloides var. purpureus are synonyms of A. dysophylloides. A. henryi, a recently published name is a synonym of A. robustus. Nine names are lectotypified. The genus occurs in South Asia, from the East Himalaya, North Thailand, and South China in the North to Sri Lanka and Peninsular Thailand in the South.     

TheMoegistorhynchus longirostris (Diptera: Nemestrinidae) pollination guild: long-tubed flowers and a specialized long-proboscid fly pollination system in southern Africa

A guild of 20 late spring- and early summer-flowering species ofIridaceae, Geraniaceae andOrchidaceae is pollinated partly or exclusively by the long-proboscid flyMoegistorhynchus longirostris (Nemestrinidae). This large-bodied fly, active in late spring and early summer, has mouthparts 40–70 (90) mm long and forages for nectar from a variety of species. These plants share a suite of convergent floral features including a straight or weakly curved floral tube usually 50–70 mm long but sometimes to 90 mm, relatively short petals or tepal lobes coloured white, cream or salmon with reddish nectar guides, and often violet or red anthers and pollen. Flowers of most species with these characteristics are zygomorphic with the stamens either arcuate (mostIridaceae) or declinate (Geraniaceae and someIridaceae). The flowers are odourless and typically secrete large amounts of nectar of relatively constant sugar concentration, mostly 24–29%, with a high sucrose:hexose ratio. Guild members utilize five separate sites of pollen deposition on the body of the fly, typically utilizing different deposition sites when two or more co-occur, indicating strong selection to aviod pollen contamination.M. longirostris is restricted to the west coast of southern Africa and at least 8 species appear to depend exclusively on the insect for pollination. The remaining species in the guild are pollinated by one or both of the long-proboscid fliesPhiloliche gulosa andP. rostrata (Tabanidae) over other parts of their range. Species and races pollinated entirely byM. longirostris have longer floral tubes which makes nectar unavailable to other insects, including other species of long-proboscid fly. The only insect with mouthparts long enough to forage effectively on these long-tubed flowers isM. longirostris and this fly must be considered a keystone species in the ecosystems in which it occurs.Dedicated to emer. Univ.-Prof. DrFriedrich Ehrendorfer on the occasion of his 70th birthday     

Host-preference and density of woodrose-forming mistletoes (Loranthaceae) on savanna vegetation,South Africa

In the Bushbuckridge region of South Africa host preference and density of two woodrose-forming mistletoes, Erianthemum dregei (Eckl. & Zeyh.) V. Tieghem and Pedistylis galpinii (Schinz ex Sprague) was quantified in relation to land-use (harvested or unharvested), rainfall (high > 660 or low < 660 mm year^–1) and catenal position (top or lower slope). These two mistletoes are generalist hemi-parasites of savanna trees and shrubs occurring on 25 and 17 hosts respectively, seven of which are shared. Thirty-six percent of woody plant species recorded were found to be hosts. Although Sclerocarya birrea (A. Rich.) Hochst. comprised only 4% of woody plant density in the environment, it was the principal host for both mistletoes, accounting for 71% of total E. dregei and 42% of P. galpinii infection. Mistletoe infection relative to density of Ficus stuhlmanii, Trichilia emetica and Cassine transvaalensis indicated that these were preferential hosts to S. birrea. Mistletoe host preference was negatively correlated with host wood density. Mistletoe number per tree had a weak relationship to canopy size. Mistletoes of all size classes were denser at high rainfall relative to low rainfall sites. Interestingly, the overall mistletoe size class distribution was similar between harvested and unharvested sites. The ratio of living to dead mistletoe was 2 to 1 for E. dregei and 1.5 to 1 for P. galpinii. There are sufficient dead mistletoes in unharvested and harvested areas to satisfy present market demand. Living E. dregei predominated in harvested rather than unharvested areas suggesting that current-harvesting levels had little or no negative effect on the population. In contrast, P. galpinii was denser in unharvested areas possibly owing to its higher market value and thus higher harvesting levels.     

Pollination biology ofTernstroemia laevigata andT. dentata (Theaceae)

The flowers of two species ofTernstroemia from Central Amazonia were observed to be pollinated by female bees performing vibrational foraging. The anthers of these flowers are longitudinally dehiscent. They are completely included in a petal tube, which opens by a small pore at the apex. Pollen is expelled out of this pore when the bees vibrate the flower while curling over the apex of the petal tube. The much elongated connectives probably transmit the vibrations from the petals to the anthers. The possible occurrence of this mode of pollination in other species ofTernstroemia is briefly discussed.     

Phylogenetic relationships in theSideritis leucantha group (Lamiaceae)

Six closely related taxa of the sect.Eusideritis of the genusSideritis (S. leucantha, S. pusilla, S. flavovirens, S. granatensis, S. biflora andS. osteoxylla) are analysed to elucidate their phylogenetic relationships and position within the sect.Eusideritis. Meiotic behaviour, karyotype features, size and fertility of pollen grains, DNA amounts and seed protein profiles are reviewed. A polyploid origin of the group (from x = 7) and the further diversification through dysploidy and chromosome repatterning is postulated.S. osteoxylla is apparently of hybrid origin.     

Reproductive isolation of two sympatric subspecies ofJuniperus phoenicea (Cupressaceae) in southern Spain

The phenology, reproductive cycle and cone crop of two sympatric subspecies ofJuniperus phoenicea (Cupressaceae) were studied during three consecutive years in southern Spain. The flowering pattern of each subspecies was constant during this period: inJ. phoenicea subsp.turbinata flowering was always in October–November, whileJ. phoenicea subsp.phoenicea flowered in February–March. There was no overlap between the flowering periods of the two taxa. The reproductive cycle of the two subspecies was similar, though there were some important differences because of their flowering times. Male cone development in both subspecies occurred in autumn, but the male cones ofJ. phoenicea subsp.phoenicea did not shed pollen until the end of February. InJ. phoenicea subsp.turbinata, the gap between pollination and fertilisation was seven months while inJ. phoenicea subsp.phoenicea it was only three months, fertilisation taking place at the same time in the two taxa. Post-fertilisation events were similar in the two subspecies, leading to a cycle of two years inJ. phoenicea subsp.turbinata and a shorter one of about 20 months inJ. phoenicea subsp.phoenicea. Alternating good and slight seed cone crops were found in both taxa during the three years studied, the good crops of one subspecies coinciding with the slight crops of the other one. Although the proximity of the two subspecies and method of pollination could make hybridisation between the taxa possible, the different flowering seasons prevent hybridisation isolating them reproductively.     

Thermal effects on activity patterns and behavioural switching in a concourse of foragers on Stachytarpheta mutabilis (Verbenaceae) in Papua New Guinea

Summary 1. The foraging activities of the papilionid butterflies Ornithoptera priamus poseidon and Papilio ulysses, and the solitary bee Amegilla sapiens (Apoidea, Anthophoridae) on the shrub Stachytarpheta mutabilis were studied in highland Papua New Guinea. 2. The insects' activity patterns were analysed at three sites with differing diurnal microclimate variation. O. priamus and A. sapiens foraged in the morning (after a period of basking and wing-whirring) and late afternoon when temperatures were well below daily maxima, whereas P. ulysses showed foraging peaks during the hottest part of the day. 3. Site choice by all 3 species appeared to be determined primarily by temperature, but within the limits imposed by temperature, nectar supplies probably determined which site was visited. 4. P. ulysses showed interspersed foraging and courtship behaviour, and no behavioural switching was observed for this species. At high temperatures, both O. priamus and A. sapiens ceased foraging and showed territorial and courtship behaviour. This behavioural change allowed avoidance of heat stress, and occurred even when nectar supplies were maintained at high levels. 5. Thermal effects on behavioural switching in these insects are compared with related phenomena in other bees and butterflies.     

Environmental correlates of gastrointestinal parasitism in montane and lowland baboons in Natal,South Africa

We compared the gastrointestinal parasites of the baboon,Papio cynocephalus ursinus, living in montane (altitude, >1800 m) and coastal lowland (altitude, 100–200 m) habitats in Natal, South Africa, using fecal analysis. While the montane animals harbored a smaller number of species, helminth egg-output rates were higher in them than in the lowland animals. The decrease in parasite diversity with increasing altitude was expected, but the difference in helminth egg output was not. It may be due to a combination of food shortage, which characterizes the montane environment, especially at the end of winter, and the high proportion of soil-contaminated items in the diets of the montane animals.     

Nutlet sculpturing of selectedTeucrium species (Lamiaceae): A character of taxonomic significance

Nutlet sculpturing of 23Teucrium species belonging to six sections was studied. The nutlets of analysed species were characterized by the presence of the oil glands of various density. SectionTeucrium is well defined by very densely distributed trichomes and oil glands on nutlets. Trichomes on nutlets were absent in all other species, except inT. marum from sect.Chamaedrys. Sect.Polium is a homogeneous group, distinguished from the other sections. There are some similarities of this sect. with sect.Scordium. Species of sect.Chamaedrys are heterogeneous and overlap according to the surface sculpturing characters with the other sections. The significance of nutlet microcharacters as additional taxonomical markers in the infrageneric classification of the genusTeucrium is discussed.