Andrew Henderson

Monocotyledons : systematics and evolution

This two-volume set dedicated to Rolf Dahlgren (1932-1986), contains 31 papers presented at an international Monocotyledons conference: Systematics and Evolution symposium at the Royal Botanic Gardens, Kew in 1993. The conference addressed systematics, mainly at family level and above, with the aim of encouraging a new classification.

A review of pollination studies in the Palmae

A review is given of the literature concerning palm pollination. Results of this review indicate great diversity in pollination, but three basic syndromes are common in the family, cantharophily, mellitophily, and myophily. Anemophily appears uncommon and derived. Evidence of a close association between certain beetles and palms may be indicative of ancestral cantharophily.ResúmenSe presenta una revisión bibliográfica sobre la biología de la polinización de las palmas. Los resultados indican que hay una gran diversidad en cuanto a los modos de polinización, pero tres de ellos dominan, cantarófila, melitófila, y miófila. La amenófila parece escasa y derivada. La asociación íntima entre ciertos coleópteros y palmas surgiere que la polinización cantarófila es ancestral.

Flowering phenology of a palm community in a central Amazon forest

The flowering phenology of 27 taxa of palms in a lowland moist forest in the central Amazon was recorded over a 40 month period. Phenological data were transformed into measures, of synchrony, regularity, and duration. Flowering was observed at all times of year and there was no correlation with rainfall either for the current month or for any monthly lag interval. The 27 taxa were divided into three pollination groups—weevil, bee/fly, or beetle—based on their behavior at anthesis. Phenology was significantly correlated with pollination groups. Weevilpollinated palms had higher synchrony and shorter duration of flowering than other groups. Bee/fly-pollinated palms had lower synchrony and longer duration of flowering. The beetle-pollinated palms were intermediate between the two other groups. Seasonal regularity of flowering was similar in all three groups. We suggest that, at least inBactris, taxa exhibit staggered flowering.AbstractA fenologia reprodutiva de 27 taxa de palmeiras foi estudada durante 40 meses em uma área de floresta tropical úmida da Amazônia central. Os dados fenológicos foram transformados em medidas de sincronia, regularidade e duração. A floração dos taxa foi observada durante todo o ano e nao foi observada correlação entre a mesma e a precipitação em um particular mês ou qualquer outro intervalo mensal. Os 27 taxa foram dividos em três grupos de acordo com os insetos polinizadores—curculionid, abelhas/moscos e besoros. Esta divisão foi baseada no comportamento dos polinizadores durante a antesis. Os resultados das medidas fenológicas são significativamente relacionados com o sistema de polinização. Palmeiras polinizadas por curculionidios apresentaram alto índice de sincronia e período mais curto de floração quando comparadas com outros grupos. Palmeiras polinizadas por abelhas ou moscas apresentaram baixa sincronia e período mais prolongado de floração. As palmeiras polinizadas por besouros são intermediarias entre os dois grupos descritos acima. O período de floração a cada ano foi regular em todos os três grupos. É sugerido que, pelo menos emBactris, os taxa exibiram floração sequencial.

A multivariate study of Calyptrogyne (Palmae)

Abstract Multivariate analyses of qualitative and quantitative characters taken from herbarium specimens of Calyptrogyne H. Wendl. (Palmae), together with analysis of geographic distributions, reveals 27 groups of specimens. Application of the Phylogenetic Species/Subspecies Concept to these groups gives 18 species and 13 subspecies, giving a total of 27 taxa in the genus. Eight species (C. tutensis, C. fortunensis, C. sanblasensis, C. baudensis, C. deneversii, C. coloradensis, C. panamensis, C. osensis) and seven subspecies (C. costatifrons subsp. occidentalis, C. costatifrons subsp. dariensis, C. allenii subsp. centralis, C. panamensis subsp. centralis, C. panamensis subsp. tutensis, C. panamensis subsp. occidentalis, C. ghiesbreghtiana subsp. hondurensis) are new, and two new combinations are made (C. ghiesbreghtiana subsp. spicigera, C. ghiesbreghtiana subsp. glauca). These taxa are distributed from southern Mexico to northwestern Colombia, with the greatest diversity in western Panama.

Pollination of Bactris (Palmae) in an Amazon forest

Phenology, inflorescence behavior, and pollination of 10 sympatric taxa ofBactris were studied in a lowland Amazon forest. Taxa flowered over an eight month period during the rainy season and early dry season, but individual taxa flowered for one to a few months. Related taxa had mostly non-overlapping flowering periods. Inflorescence behavior was similar for all taxa, with nocturnal pistillate anthesis and temperature elevation, followed 24 hours later by rapid, nocturnal staminate anthesis. Pollinators of all taxa were small weevilsPhyllotrox (Curculionidae) and nitidulidsColopterus (Nitidulidae), although various other insect visitors were recorded. Large numbers ofPhyllotrox were recorded on inflorescences, but weevil sex ratios were highly skewed.ResumenA fenologia, padrão de abertura da inflorescência e polinização de 10 espécies simpátricas deBactris foram estudadas em florestas de terras baixas da Amazônia. A floração se estendeu durante um período de oito meses durante a estação chuvosa e inicio da estação seca, porém algumas espécies floresceram durante um ou alguns meses. O período de floração de espécies relacionadas foi quase sempre não coincidente. O padrão de abertura das inflorescências foi similar em quase todas as espécies. A antesis das flores pistiladas ocorreu à noite acompanhada de uma elevação da temperatura e uma rápida natesis noturna das flores estaminadas nas 24 horas seguintes. Os polinizadores em todas as espécies eram pequenos besourosPhyllotrox (Curculionidae) e nitidulidsColopterus (Nitidulidae), porém outros insetos visitantes foram observados. Grande número dePhyllotrox foi observado nas inflorescências, porém a proporção entre machos e fêmeas foi muito desigual.

A multivariate analysis of Hyospathe (Palmae).

Previous systematic treatments of the neotropical palm genus Hyospathe have recognized from two to 18 species. An explicit, quantitative, repeatable sequence of operations for delimiting and testing groups of specimens and applying species concepts is carried out. Multivariate statistical analysis of morphological data is used to delimit and test groups of specimens. Cluster analysis is used to distinguish between characters and traits. Analysis of qualitative and quantitative characters reveals six groups of specimens, and the Phylogenetic Species Concept is applied to these groups. Two species, H. peruviana Henderson and H. frontinensis Henderson, are described as new. One of the specimen groups is large and widespread, and six geographically separate subgroups can be recognized within it. These subgroups can be distinguished by one or more significantly different quantitative characters. A Phylogenetic Subspecies Concept is applied to these subgroups. Three subspecies, H. elegans subsp. costaricensis Henderson, H. elegans subsp. sanblasensis Henderson, and H. elegans subsp. tacarcunensis Henderson are described as new, and two new combinations are made: H. elegans subsp. sodiroi (Dammer ex Burret) Henderson and H. elegans subsp. concinna (H. E. Moore) Henderson. One subspecies occurring in the Amazon region is complex morphologically and is not resolved by the methods used here.

Geographic and taxonomic disparities in species diversity: dispersal and diversification rates across Wallace's line.

Broad‐scale patterns of species diversity have received much attention in the literature, yet the mechanisms behind their formation may not explain species richness disparities across small spatial scales. Few taxa display high species diversity on either side of Wallaces Line and our understanding of the processes causing this biogeographical pattern remains limited, particularly in plant lineages. To understand the evolution of this biogeographical pattern, a time‐calibrated molecular phylogeny of Livistoninae palms (Arecaceae) was used to infer the colonization history of the Sahul tectonic plate region and to test for disparities in diversification rates across taxa and across each side of Wallaces Line. Our analyses allowed us to examine how timing, migration history, and shifts in diversification rates have contributed to shape the biogeographical pattern observed in Livistoninae. We inferred that each of the three genera found in Sahul crossed Wallaces Line only once and relatively recently. In addition, at least two of the three dispersing genera underwent an elevation in their diversification rate leading to high species richness on each side of Wallacea. The correspondence of our results with Southeast Asian geologic and climatic history show how palms emerge as excellent models for understanding the historical formation of fine‐scale biogeographic patterns in a phylogenetic framework.

Phenetic and phylogenetic analysis of Reinhardtia (Palmae)

Principal component analysis and cluster analysis of morphometric data divide specimens of Reinhardtia into six groups, corresponding to the six species recognized in the most recent revisions. Discriminant analysis classifies specimens into these six species with 100% success. Five species occur in lowland to montane moist forests in Central America, from Mexico to Panama, and just reach Colombia; one species occurs in montane moist forests in Hispaniola. Three species have large stems and are rare, patchily distributed, and seldom collected. The other three species have small stems, are common and frequently collected, but also patchily distributed. One species of small plants, R. gracilis, exhibits considerable variability. Within this species, seven distinct groups can be recognized, although sample size is limited. Among species, there is a phyletic decrease in size of plants, from the basal species with large stems to derived species with small stems. For leaves and inflorescences there is also an associated decrease in size, but one species does not follow this trend. In this species, R. latisecta, there is evidence of a large ontogenetic change in leaf development. Phyletic decrease in size corresponds to a latitudinal and elevational gradient suggesting speciation has taken place from north to south and from high to low elevation. However, this pattern is obscured disjunct distributions in some species.

Diseases and Disorders of Ornamental Palms.

Martius, C. F. P. von. 1837. Historia naturalis palmarum. Vol. 2. Genera et species. T. O. Weigel, Leipzig. Wessels Boer, J .G . 1965. The indigenous palms of Suriname. E. J. Brill, Leiden. 1968. The Geonomoid palms. Verh. Kon. Ned. Akad. Wetensch., Afd. Natuurk., Tweede Reeks 58: 1-202. 1972. Clave descriptiva de las palmas de Venezuela. Acta Bot. Venez. 6: 299-362. 1988. Palmas indigenas de Venezuela. Pittieria 17: 1-332.

A FLÓRULA DA RESERVA DUCKE, I: PALMAE (ARECACEAE)

This is the first taxomomic treatment of a family for the Fiorala of the Ducke Reserve. Fourteen genera with 35 species are treated for the palm family, with keys to all genera and species and brief descriptions of all species. The keys are based on characters found on fertile herbarium specimens. Listed by decreasing diversity, the genera are: Bactris(8), Geonoma(6), Astrocaryum(5), Attalea(3), Oenocarpus(3), Euterpe(2), Desmoncus(1), Hyospathe(1), irianella(1), Manicaria(1), Mauritia(1), Mauritiella(1), Socratea(1) and Syagrus(1).