Reproductive features of Celmisia species (Asteraceae) in relation to altitude and geographical range in New Zealand

A range of seed and flower characters was examined in 37 species of the New Zealand genus Celmisia (Asteraceae) to determine whether there were any relationships between reproductive features and the geographic or altitudinal ranges of the species. Using published sources and herbarium material, flower attractiveness to pollinators was measured in terms of capitulum size and ray/disc length ratio. Dispersibility was measured in terms of seed dry weight, seed terminal velocity, pappus/seed length ratio, and scape/leaf length ratio. Altitude (minimum and maximum) and geographic ranges (number of 1^o latitude x 1^o longitude squares occupied) were obtained from published sources. A multivariate principal components analysis using 12 morphological characters revealed the presence of five groups of species differing in capitulum size, seed weight, pappus length, number of pappus bristles, leaf length and scape length. Linear regressions showed that altitude was significantly and negatively related to seed dry weight and capitulum size, and positively to scape/leaf length ratio. Geographic range is negatively related to capitulum size, and positively to ray/disc ratio and altitudinal range. Amongst the seed features measured, seed weight was the best predictor of terminal velocity (an inverse measure of dispersability), but lighter seeds also had a higher pappus/seed length ratio. The frequency distribution of the geographic ranges of the species is highly skewed, with many local species (86% occurring in 15 or fewer one‐degree squares) and very few common ones. Two species (C. gracilenta and C. graminifolia) are notably more common than all the others. A comparison of these species with the others shows that, on average, they have lighter seeds with more bristles, taller scapes and higher ray/disc ratios, but have smaller capitula. The low geographic abundance of the rare species could not readily be attributed to any specific reproductive feature, possibly because of the multiple types of rarity represented within the genus.     

Systematic overview of Krigia (Asteraceae-Lactuceae)

Cytological and morphological variation among Krigia species is examined. Krigia exhibits a broad range of chromosome numbers including n = 4, 5, 6, 9, 10, 15, and 30. Section Krigia is characterized by reflexed phyllaries and a base chromosome number of x = 5, while section Cymbia is characterized by erect phyllaries and chromosome numbers of n = 4, 6, and 9. The micromorphological characteristics of achenes, pappus, styles, corolla, pollen, stomata, and trichomes are documented using scanning electron microscopy. Among these, the pappus shows the greatest diversity and three major types are identified: 1) a pappus of many bristles and scales, as in K. dandelion, K. montana, and K. biflora; 2) a pappus of five bristles and five scales, as in K. virginica and K. occidentalis; and 3) an absent or highly reduced pappus, as in the K. cespitosa complex and K. wrightii. Thirty-five cytological and morphological characters are subjected to phylogenetic analyses. The two sections, Krigia and Cymbia, form monophyletic lineages. Within section Krigia, the annual species, K. virginica, forms an independent clade, while the perennial species, K. dandelion, K. biflora, and K. montana, form a monophyletic clade. Krigia montana and K. biflora are identified as sister species and a hybrid between these has been identified. The hybrid is more similar morphologically to K. montana than K. biflora. Within section Cymbia, phylogenetic relationships among K. wrightii, K. occidentalis, and K. cespitosa are uncertain. Nine taxa of Krigia are herein recognized: K. dandelion, K. biflora, K. biflora var. viridis (comb. nov.), K. montana, K. virginica, K. wrightii (comb. nov.), K. occidentalis, K. cespitosa, and K. cespitosa f. gracilis (comb. nov.). Phylogenetic relationships among 12 taxa of Krigia species are compared using various combinations of morphology, chloroplast DNA, and nuclear ribosomal DNA data. Tree topologies from different combinations of data are largely congruent. The most resolved phylogenetic tree is obtained using the combined data from morphology, chloroplast DNA, and nuclear ribosomal DNA.     

A new genus and a new species of tachinids (Diptera,Tachinidae) from the south of middle Asia

Ventoplagia gen. n. is described, with the type species Ventoplagia brevirostris sp. n. The frontal bristles extending only to the base of the pedicel, 2+3 dorsocentral bristles, 0+2 intraalar bristles, the absence of prealar bristle, the short and fine anepimeral (pteropleural) bristle, the scutellum without lateral bristles, and the welldeveloped posteroventral bristle of the hind tibia indicate that the new genus belongs to tribe Minthoini. Ventoplagia gen. n. is closely related to the genus Palmonia Kugler. The characters distinguishing these genera are given.     

Facial bristle feather histology and morphology in New Zealand birds: Implications for function

Knowledge of structure in biology may help inform hypotheses about function. Little is known about the histological structure or the function of avian facial bristle feathers. Here we provide information on morphology and histology, with inferences for function, of bristles in five predominantly insectivorous birds from New Zealand. We chose species with differing ecologies, including: brown kiwi (Apteryx mantelli), morepork (Ninox novaezealandae), hihi (Notiomystis cincta), New Zealand robin (Petroica australis), and New Zealand fantail (Rhipidura fuliginosa). Average bristle length corrected for body size was similar across species. Bristles occurred in distinct groups on different parts of the head and upper rictal bristles were generally longest. The lower rictal bristles of the fantail were the longest possessed by that species and were long compared to bristles of other species. Kiwi were the only species with forehead bristles, similar in length to the upper rictal bristles of other species, and the lower rictal bristles of fantails. Herbst corpuscles (vibration and pressure sensitive mechanoreceptors) were found in association with bristle follicles in all species. Nocturnal and hole‐nesting birds had more heavily encapsulated corpuscles than diurnal open‐nesting species. Our results suggest that avian facial bristles generally have a tactile function in both nocturnal and diurnal species, perhaps playing a role in prey handling, gathering information during flight, navigating in nest cavities and on the ground at night and possibly in prey‐detection. These differing roles may help explain the observed differences in capsule thickness of the corpuscles. J. Morphol., 2011. © 2010 Wiley‐Liss, Inc.     

A CLADISTIC ANALYSIS OF LUCILIA CASS. (COMPOSITAE, INULEAE)

Abstract— Lucilia is a South American genus with 23 species restricted to disjunct areas in southeastern Brazil and along the Andes. Lucilia is a monophyletic group defined by the co-occurrence of six characters: herbaceous, alternate-leaved, pappus with scabrid bristles fused at the base into a ring, style-branches with sweeping hairs far down, capitula sessile, and aseptate-flagellate hairs. A dadogram is presented using 41 morphological and anatomical characters arranged into 26 transformation series. The polarity of character states was determined by outgroup comparison with the genus Berroa. The cladistic analysis showed extensive parallel evolution in a number of the more conspicuous characters and produced four unresolved trichotomies. However, basing the hierarchy of Lucilia on the branching pattern produced by cladistic analysis results in a more natural and predicitive classification. Lucilia is divided into three sections, Lucilia, Intermedieae (sect, nov), and Lucilioides [divided into two subsections, Subspicata (subsect. nov.) and Lucilioides]. The latter subsection is subdivided into two series, Lucilioides (ser. nov.) and Paralucilia. The Brazilian species of section Lucilia (acutijolia, linearifolia, ferruginea, tmentosa, recurva, nitens, and flagelliformis) form the most primitive group within the genus. The more derived species of the genus, section lucilioides (plicatifolia, catamarcensis, burkartii, subspkata, lopezmirandae, alpina, pickeringii, piptolepis, santamca, chilensis, schultzii, longifolia, radians, lehmanni, pusilla) are found in the Andes L. eriophora (section Intermedieae) from central Chile bridges these two groups. An explanation for the distribution of the genus is given, based on the ecology of the species in relation to theories of the geologic and climatic history of South America. The present pattern has been determined by the age, geographical range, and vicissitudes of the habitat in which each group occurs. In the Brazilian species group, the habitat is old, and has remained relatively stable since well before the Pleistocene. In the Andean species group, the habitat is young and has undergone numerous rapid alterations since its inception at the end of the Pliocene.     

Realized evolvability: quantifying phenotypic evolution in a Drosophila clade

Understanding the evolutionary potential of morphological evolution is still a major problem in evolutionary biology. In this study, we tried to quantify the amount of variation of different traits among species of a Drosophila clade reared under standard conditions. Nineteen different traits have been measured on nine species of the same clade, the Neotropical saltans group of Drosophila. Measured traits can be distributed into five categories: size‐traits (wing and thorax), shape indices (ratios among the size traits), number of sternopleural bristles on the thorax, number of abdominal bristles on successive sternites, and dorsal pigmentation of abdomen. All species are of medium size with a generally dark pigmentation. A remarkable feature is the presence of numerous bristles on the 6th sternite of the males, while this segment is bare in other Drosophila species. A multivariate analysis revealed that it was possible to discriminate all the investigated species by using the complete set of measured traits. For each trait, phenotypic variability was investigated at the within‐ and between‐species levels. As a rule, the interspecific coefficient of variation (CV) was much greater than the within species CV, and it is proposed to call it realized evolvability. All possible correlations were calculated between traits across species, providing many unexpected results. Size traits were highly correlated among them, but not correlated with shape indices. Abdominal traits (bristles and pigmentation) were correlated, but often in opposite directions, with thoracic shape indices. Tergite pigmentation was negatively correlated with bristle number on sternite. For the moment, most of the correlations cannot be explained by developmental processes or parallel selective pressures. Nonetheless, mapping the evolution of the two characters on a molecular phylogeny of the studied species revealed two opposite phylogenetic trends for abdominal pigmentation and setation, respectively. Our data suggest a need for similar studies in other well‐defined Drosophila clades.     

Morphological characters add support for some members of the basal grade of Asteraceae

Recent molecular studies in Asteraceae have divided tribe Mutisieae (sensu Cabrera) into 13 tribes and eight subfamilies. Each of the major clades is well supported but the relationships among them are not always clear. Some of the new taxa are easily characterized by morphological data but others are not, chief among the latter being three subfamilies (Stifftioideae, Wunderlichioideae and Gochnatioideae) and the tribe Hyalideae. To understand evolution in the family it is critical to investigate potential morphological characters that can help to evaluate the basal lineages of the Asteraceae. The data for this study were taken from 52 species in 24 genera representing the basal groups in the family. Many characters were examined but most of the useful ones were from reproductive structures. Several apomorphies supported a few of the clades. For instance, members of subfamily Wunderlichioideae (Hyalideae and Wunderlichieae) share predominantly ten‐ribbed achenes and members of Wunderlichioideae + Stifftioideae share two synapomorphies: 100–150 (200) pappus elements, arranged in (three) four or five series. These apomorphies can be viewed as an indication of a sister‐group relationship between the two subfamilies as the placement of Stifftieae was not well resolved by the molecular data. Members of Wunderlichieae are characterized by having a paleaceous receptacle, style branches that are strongly papillose above and below the bifurcation, and a pappus of scales. Hyalis and Ianthopappus (Hyalideae) share venation type and an apiculate anther appendage but these are also found in Gochnatieae. Other clades have fewer supporting characters. These characters are just a beginning. Cladograms with morphology characters plotted, illustrations and a key to the basal grade of Asteraceae are provided. © 2013 The Linnean Society of London     

Reconstructing the biogeographical history of two plant genera with different dispersion capabilities

Aim The pappus is one of the most distinctive features of the genera belonging to the sunflower family, and is an efficient mechanism for dispersion by wind. The pappose Holocheilus (seven species) and the non‐pappose Panphalea (nine species) are two genera of the monophyletic subtribe Nassauviinae (Asteraceae, Mutisieae), which overlap in their areas of distribution. This paper aims to reconstruct the biogeographical histories that shaped the distribution of these two genera, which are phylogenetically and geographically related, but differ in their means of dispersion. Our initial expectation was that the dispersion capability of the pappus should be reflected in more dispersal events in Holocheilus than in Panphalea. Location South‐eastern Brazil, Paraguay, Uruguay and Argentina. Methods Morphological data were acquired from the literature and by analysis of specimens. Two cladistic analyses, one for Holocheilus and one for Panphalea, were based on morphological characters, and data matrices were analysed with the Fitch parsimony algorithm of paup . The ancestral distributions were reconstructed using diva ver. 1.1 according to the dispersal–vicariance optimization method. Results The Paranense‐fields were identified as the most likely ancestral area of Holocheilus and Panphalea. Biogeographical reconstruction of Holocheilus shows several dispersal events from the Paranense‐fields: two ancestral dispersal events to the Yungas, followed by vicariance events (Paranense‐fields/Yungas) and numerous terminal dispersals to the surrounding areas such as Chacoan, Pampean and Espinal. diva reconstruction of Panphalea distribution also shows frequent terminal dispersals, with no vicariant events, from the Paranense‐fields to the other areas: (1) to Espinal, Pampean‐Uruguayan, Pampean‐oriental; (2) to Paranense‐hills; (3) to Pampean‐Uruguayan; and (4) to Paranense‐pine lands. Main conclusions In the past, both genera probably originated in the Paranense‐fields area, which was subject to the dry and humid cycles of the Quaternary glaciations. Dispersal was the process that predominantly shaped the distribution of Panphalea and Holocheilus, with approximately the same number of dispersal events in both genera, despite differing ranges of dispersion. The main barriers to dispersal were the dry Cerrado and Chaco, the latter promoting vicariance in Holocheilus. The lack of a pappus in Panphalea was a limitation for its dispersion compared with Holocheilus.     

Pollen‐feeding in hover‐flies (Diptera: Syrphidae)

Analyses of the pollen contents of the crop and intestine of 11 species of New Zealand Syrphidae . showed that small, sparsely haired hover‐flies with unbranched hairs, short, simple bristles, and a short proboscis had ingested at least 99% anemophilous pollens, and that larger, more hairy hover‐flies with pollen‐collecting hairs, long, spirally grooved bristles, and elongate mouthparts had ingested pollens almost exclusively from nectar‐bearing flowers. Pollen‐feeding behaviour was studied in one hairy species, the drone‐fly Eristalis tenax, and in one sparsely‐haired species, Melanostoma fasciatum. Using granulated charcoal as a substitute for pollen, it was found that in E. tenax particles trapped among the body hairs are combed off by the front and hind tibiae and transferred to pollen‐retaining bristles on the front and hind tarsi respectively. Particles retained among the front tarsal bristles are ingested directly from the bristles. Those retained by the hind tarsi are transferred in flight by leg‐scraping movements to the front tarsi, from which they are subsequently eaten. E. tenax also eats pollen directly from anthers. In M. fasciatum apparently all the pollen ingested is taken directly from anther lobes or stigmas. The few pollen grains that adhere to the body of this species are combed off by the front and hind tibiae and transferred to the front and hind tarsi, but are not retained there because the bristles are short and simple. The mouthparts, hairs, and bristles of E. tenax and M. fasciatum are illustrated. Drawings of leg movements associated with pollen collection and ingestion, and photographs showing leg scraping in E. tenax are included. Morphological similarities between drone‐flies and honey‐bees, previously regarded as the result of mimicry, can be explained by convergent evolution in response to similar food‐gathering behaviour. Probably the majority of Syrphidae, and also the related Acroceridae, collect pollen by means of branched or curly‐tipped hairs.     

Variability of the inflorescence ofMicroseris laciniata (Compositae: Cichorieae)

Quantitative characters of the flowering head of a garden population ofMicroseris laciniata were scored during the second, third, and fourth season of growth. Number of achenes per head, number of phyllaries per head and the average number of pappus parts per achene in single heads show significant plant to plant variation. Achenes per head and pappus parts per achene were scored in identical plants in two subsequent seasons. The number of pappus parts per achene varies freely between five and ten. This contrasts with annual species ofMicroseris in which either five or ten pappus parts are found, depending on the species. In spite of a clear plant-specific average of pappus parts, both high and low pappus part determination can be demonstrated in all specimens. The number of pappus parts depends on the position of an achene on the receptacle, marginal achenes usually having fewer pappus parts than central ones. This gradient is not closely correlated with the position of an achene on the genetic spiral.     

Lindernia kinmenensis sp. nov. (Scrophulariaceae) from Kinmen (Taiwan)

Lindernia kinmenensis Y. S. Liang, C. H. Chen, & C. L. Tasi sp. nov. from Kinmen (Taiwan) is described. The new species belongs to section Torenioides and is most similar to L. crustacea. It differs from the latter by the following characters: calyx pubescent between the ridges (vs pubescent on ridges), with (2)3(4) bristles on the ridge near the apex of the calyx‐lobes (vs without such bristles), corolla shorter, 6–8 mm long (vs 7–11 mm long) and pale purple (vs purple or blue), posterior theca with obtuse (vs acute) apex. This species is usually found in sandy wetlands. A line drawing, colour photos and SEM micrographs of pollen and seed as aids for identification are provided.     

Achene morphology of Saussurea species (Asteraceae,Cardueae) in Korea and its systematic implications

Achene size and shape, surface sculpturing, and pericarp and testa wall structure of 23 Korean Saussurea spp. were investigated using scanning electron microscopy (SEM) and light microscopy to evaluate the infrageneric relationships and assess their systematic significance. Achene size categories and thickness of the testa epidermis were distinguished using biometric measurements. Four basic types of surface pattern were observed: (1) lineate; (2) striate; (3) reticulate; and (4) colliculate. Saussurea rorinsanensis was found to have some unique achene characteristics, such as a fusiform achene, uniform pappus, presence of epidermal hairs and tangentially elongated, narrow testa epidermal cells. The characteristic achene features for species were found to be achene size and shape, hilum position, surface sculpture, pappus composition, morphology of the pericarp wall and thickness of the testa epidermis. Based on 16 morphological and achene characters, a cladistic analysis resolved three well‐supported clades, with S. eriophylla as the first‐branching taxon. Saussurea pulchella and S. japonica, both belonging to Saussurea subgenus Theodorea, were distant from each other in the 50% majority rule consensus tree and the character distribution cladogram. This cladistic analysis of achene morphology and anatomy should be regarded as giving us a tentative picture of the phylogenetics of Saussurea, and this study may serve as a reference for future hypotheses and studies on the characterization and classification of Saussurea spp. in Korea.     

Comparative capitular morphology and anatomy of Coreopsis L. and bidens L. (compositae), including a review of generic boundaries

The capitular and floral morphology and anatomy ofBidens L. andCoreopsis L. were studied. All the North American species ofCoreopsis were studied. Selected species ofBidens from North and South America andCoreopsis from South America were included. The results were compared with previous observations on African species ofBidens (incl.Coreopsis). Emphasis was given to character states of the ray florets, paleae, stylearm apices, outer phyllaries, achenes, and pollen grains. Some of the character states are unique features ofCoreopsis, e.g., globular and elongately conical receptacles, deltoid outer phyllaries, truncate and indistinctly 3–5-dentate, 3–4-lobed ray florets, narrowly spathulate paleae, subulate paleae with linear-filiform upper half, hairy and apically 3-cleft paleae, truncate, convex or shallowly conical stylearm apices with the sweeping hairs limited to the area above the stigmatic surfaces and the orbicular to circular achenes. The cylindric setaceous pappus bristles so commonly encountered inBidens are unknown inCoreopsis. The pappus bristles inCoreopsis are paleaceous but similar, though thicker ones are also found in African species ofBidens (incl.Coreopsis) with winged achenes. Twin-celled hairs (setulae) with differing degrees of wall thickness are found on the achenes ofCoreopsis sect.Pseudoagarista (Mexico and South America),Coreopsis sect.Pugiopappus (California), AfricanBidens with winged achenes (e.g.,B. prestinaria, B. macroptera) and some North AmericanBidens (e.g.,B. aristosa). Similar sclerotic parenchyma make up the achenial wings of species in both genera. These may be interpreted as homologous structures, indicating the underlying similarity of these taxa and their derivation from a common ancestral stock.     

Pappus part number in annual species ofMicroseris (Compositae,Cichoriaceae)

All North American annual species of the genusMicroseris have a five-part pappus, the one South American annual,M. pygmaea, has ten pappus parts. The pappus develops over a constant number of ten provascular bundles with or without inhibition between alternate sites of pappus development. Each natural population contains a predictable proportion of achenes with aberrant pappus part numbers. Hybridization betweenM. bigelovii (5 parts) andM. pygmaea results in F 1 and F 2 plants with many aberrant achenes. In each plant either five or ten can be shown to be the basic number with aberrant numbers following a Poisson distribution for numbers added to 5 or deleted from 10. Occasional plants show no basic number but have a random distribution of numbers about an intermediate mean. The evolutionary genetics of this character is discussed.     

Differential responses to fertilization and competition among invasive,noninvasive alien,and native Bidens species

Comparative studies of invasive, noninvasive alien, and native congenic plant species can identify plant traits that drive invasiveness. In particular, functional traits associated with rapid growth rate and high fecundity likely facilitate invasive success. As such traits often exhibit high phenotypic plasticity, characterizing plastic responses to anthropogenic environmental changes such as eutrophication and disturbance is important for predicting the invasive success of alien plant species in the future. Here, we compared trait expression and phenotypic plasticity at the species level among invasive, noninvasive alien, and native Bidens species. Plants were grown under nutrient addition and competition treatments, and their functional, morphological, and seed traits were examined. Invasive B. frondosa exhibited higher phenotypic plasticity in most measured traits than did the alien noninvasive B. pilosa or native B. bipinnata. However, differential plastic responses to environmental treatments rarely altered the rank of trait values among the three Bidens species, except for the number of inflorescences. The achene size of B. frondosa was larger, but its pappus length was shorter than that of B. pilosa. Two species demonstrated opposite plastic responses of pappus length to fertilization. These results suggest that the plasticity of functional traits does not significantly contribute to the invasive success of B. frondosa. The dispersal efficiency of B. frondosa is expected to be lower than that of B. pilosa, suggesting that long‐distance dispersal is likely not a critical factor in determining invasive success.     

Aristolochia bhamoensis sp. nov. (Aristolochiaceae) and a diagnostic key to all known A. subgen. Siphisia species from Myanmar

Aristolochia bhamoensis from Myanmar is here described and illustrated. This new species is morphologically similar to A. faviogonzalezii (confined to northern Vietnam) and A. cathcartii (growing in the Himalayan region) but is distinguished from the latter two species by having a cream‐white upper part of the perianth tube, with visible purple ridges, a trumpet‐shaped limb, 5.0–5.5 cm diameter, inner surface of limb lobes densely covered with dark‐purple bristles, a nearly circular mouth, 3.2–3.5 cm wide, upper half of throat being dark‐purple to blackish, without striations or dots, and lower half purple, with conspicuous white striation. Morphological characters such as a 3‐lobed gynostemium and a 3‐lobed limb support a placement of the new species in the subgenus Siphisia. A diagnostic key is provided to the seven Siphisia species known from Myanmar.     

Ligularia zhengyiana sp. nov. (Asteraceae) from the Hubei Province,China

The new species Ligularia zhengyiana from the Hubei Province, China, is described and illustrated. It is characterized by dense blackish purple pilose hairs on the stems and by coarsely triangular‐dentate leaves. Ligularia zhengyiana is similar to L. fischeri (Ledeb.) Turcz., but L. zhengyiana has dense long blackish purple hairs on stems, while L. fischeri is glabrous or has short yellowish‐brown hairs on stems. In addition, the pappus of L. zhengyiana is white, while that of L. fischeri is yellowish‐brown.     

A cladistic analysis of Nassauvia Comm. ex Juss. (Asteraceae, Mutisieae) and related genera

FREIRE, S. E., CRISCI, J. V. & KATINAS, L., 1993. A cladistic analysis of Nassauvia Comm. ex Juss. (Asteraceae, Mutisieae) and related genera. Nassauvia and the most closely related genera Calopappus and Triptilion from the southern Andes and Patagonia of South America, form a monophyletic group diagnosed by the following synapomorphies: cypsela trichomes single two-celled, cypsela testa with strengthened cells, pollen grains spheroidal to spheroidal-oblate, colpi membrane with sexine processes, pappus bristles two to six, and pappus deciduous. Furthermore, Nassauvia, Triptilion, and Calopappus form a group with two other Andean genera, Moscharia and Polyachyrus, diagnosed by occurrence of pseudocephalia and a reduction in the number of flowers to five, three or one. A cladistic analysis of the group was undertaken using 35 characters from morphology, anatomy, and palynology. The monophyletic terminal taxa were the 38 species of Nassauvia, the genus Triptilion, the monotypic genus Calopappus, the genus Polyachyrus, and the genus Moscharia. Character polarity was based on outgroup comparison using Cephalopappus. The analysis resulted in 223 equally parsimonious cladograms, each with 70 steps and a consistency index of 0.57. A successive weighting procedure was applied, resulting in 15 cladograms with a consistency index of 0.82. Results of the cladistic analysis support most of the current systematic classification of Nassauvia, with three exceptions: (1) Nassauvia (excluding Calopappus) is paraphyletic; (2) section Masligophorus appears to be a polyphyletic group (N. pygmaea does not cluster with the remaining species of the section); (3) section Panargyrum (without N. lagascae= section Caloptilium) appears to be a paraphyletic group. The capitula arranged in cymose conflorescences in Triptilion are regarded as a primitive condition which gave rise to all stages present in Nassauvia (conflorescence spicate, pseudocephalium, capitula solitary). The capitula arranged in pseudocephalia in Moscharia and Polyachyrus are regarded as a parallel development to the pseudocephalium found in Nassauvia. Nassauvia, subgenus Strongyloma appears as the most primitive taxon, with its spicate conflorescence, whereas section Masligophorus with its solitary capitulum is thought-derived. These results correspond well with cytological data where species of the subgenus Strongyloma have n= 11 and the species of section Masligophorus are tetraploids (n = 22).