Madeline M. Harley

Complete Generic-Level Phylogenetic Analyses of Palms (Arecaceae) with Comparisons of Supertree and Supermatrix Approaches

Supertree and supermatrix methods have great potential in the quest to build the tree of life and yet they remain controversial, with most workers opting for one approach or the other, but rarely both. Here, we employed both methods to construct phylogenetic trees of all genera of palms (Arecaceae/Palmae), an iconic angiosperm family of great economic importance. We assembled a supermatrix consisting of 16 partitions, comprising DNA sequence data, plastid restriction fragment length polymorphism data, and morphological data for all genera, from which a highly resolved and well-supported phylogenetic tree was built despite abundant missing data. To construct supertrees, we used variants of matrix representation with parsimony (MRP) analysis based on input trees generated directly from subsamples of the supermatrix. All supertrees were highly resolved. Standard MRP with bootstrap-weighted matrix elements performed most effectively in this case, generating trees with the greatest congruence with the supermatrix tree and fewest clades unsupported by any input tree. Nonindependence due to input trees based on combinations of data partitions was an acceptable trade-off for improvements in supertree performance. Irreversible MRP and the use of strictly independent input trees only provided no obvious benefits. Contrary to previous claims, we found that unsupported clades are not infrequent under some MRP implementations, with up to 13% of clades lacking support from any input tree in some irreversible MRP supertrees. To build a formal synthesis, we assessed the cross-corroboration between supermatrix trees and the variant supertrees using semistrict consensus, enumerating shared clades and compatible clades. The semistrict consensus of the supermatrix tree and the most congruent supertree contained 160 clades (of a maximum of 204), 137 of which were present in both trees. The relationships recovered by these trees strongly support the current phylogenetic classification of palms. We evaluate 2 composite supertree support measures (rQS and V) and conclude that it is more informative to report numbers of input trees that support or conflict with a given supertree clade. This study demonstrates that supertree and supermatrix methods can provide effective, explicit, and complimentary mechanisms for synthesizing disjointed phylogenetic evidence while emphasizing the need for further refinement of supertree methods.

Pollen aperture morphology in Arecaceae: Application within phylogenetic analyses, and a summary of record of palm-like pollen the fossil

For a monocotyledonous family, the Arecaceae possess unusually varied pollen, not only in aperture number and orientation, but also in exine ornamentation. Although the majority of species have monosulcate pollen, 17 aperture types, and 13 exine types, have been described. The family belongs to a minority of monocotyledonous families in which both successive and simultaneous cytokinesis occur. The aperture types that have been described for the Arecaceae can be separated into those associated with successive, and those associated with simultaneous, cytokinesis. Palms have a long fossil record, mainly leaves and pollen, but also fruits, stems, and roots. Flowers have also been recovered. Distinctive aperture and/or exine combinations, in the pollen of some species, have prompted comparisons with fossil pollen taxa, certainly from the Late Cretaceous onwards. Occurrences of various fossil pollen taxa, frequently associated with palms, are reviewed, and their morphologies, particularly aperture characteristics, are compared with those of living palm pollen. The systematic rarity of most palm aperture types places limitations on their value in cladistic analyses. Nevertheless, certain aperture characters are of value, and do contribute to a better understanding of the evolution and phylogeny of the family. The differences between aperture types and aperture characters are addressed. The seventeen aperture types are described, and the interpretation and use of aperture characters in cladistic analyses of the Arecaceae are discussed.

Pollen morphological studies in tribe Ocimeae (Nepetoideae : Labiatae). I : Ocimum L.

Abstract The pollen of 20 species, 53 collections, of Ocimum and 6 species from 4 closely allied genera: Becium Lindl., Dauphinea Hedge, Erythrochlamys Guerke and Orthosiphon Benth. was acetolysed and examined with light, scanning electron and transmission electron microscopy. Four pollen types are described, three are subdivided. Keys are provided to the types and subtypes. Results show some notable parallels with taxonomic opinion. A number of examples are cited in which the pollen morphology supports recent or proposed taxonomic changes, for example the transfer of Erythrochlamys cufodontii Lanza and E. nummularia (S. Moore) Hedge to Ocimum, of Ocimum hanningtonii Baker to Orthosiphon and of both Ocimum irvinei J. K. Morton and O. urundinense Robyns & Lebrun to Becium. Parallels with pollen types are drawn between Old and New World species; Pollen Type I occurs in both the Old and New Worlds while Pollen Types II, III and IV are exclusively Old World. Data from geographic distribution and pollen morpho...

1. OCIMUM: AN OVERVIEW OF CLASSIFICATION AND RELATIONSHIPS

The taxonomy and nomenclature of Ocimum are in a state of confusion. The aim of this paper is to clearly delimit Ocimum from related genera, provide an upto-date infrageneric classification which can be used as a framework for understanding relationships within the genus, provide a list of recognised species with their correct names and common synonyms and a key to their identification. In all 64 species are recognised. A parsimony analysis was carried out which suggests Ocimum is a monophyletic group if segregate genera such as Becium and Erythrochlamys are included within it. An account of the morphological features of Ocimum is provided and the economic uses of the genus are briefly discussed in the context of the infrageneric classification.

Occurrence of simple, tectate, monosulcate or trichotomosulcate pollen grains within the Palmae

Abstract Considerable variation in pollen morphology exists within the Palmae (Arecaceae). However, a high percentage of species have pollen which is tectate, monosulcate, with an unsculptured or finely sculptured, usually perforate exine, generally regarded as the least specialized pollen type. The present paper summarises and discusses the widespread occurrence of this simple pollen type within the family and reconsiders the sporadic occurrence of trichotomosulcate pollen grains. The possibility that these superficially similar pollen may have sufficient modifications to the tectum and exine stratification to be of value for identification is considered.

Phylogenetic relationships in Burseraceae based on plastid rpsl6 intron sequences

Summary. The intron of the plastid rpsl6 gene was sequenced for 13 species in 11 genera of Burseraceae and three genera of Anacardiaceae. Parsimony analysis produced just three strongly supported trees. Canarieae and Protieae are shown to be monophyletic with 100% bootstrap support. Bursereae, however, are paraphyletic with two distinct clades corresponding to the subtribes. The hypothesised, but never formally recognised, close association between the genera Garuga and Boswellia is reinforced. The close association between the South American genus Bursera and African genus Commiphora is clearly demonstrated. The position of the recently discovered Beiselia is resolved as a distant sister to the rest of

Ultrastructural studies of some fossil and extant palm pollen, and the reconstruction of the biogeographical history of subtribes Iguanurinae and Calaminae

Abstract Two monosulcate and one disulcate palm-like pollen types are described from a Middle Eocene lignite sample at Watupuru River, near Kalisonggo, Nanggulan, Central Java. Their morphologies are described by light, scanning electron and transmission electron microscopy. Systematically arranged, morphological data of recent palm pollen are used as a broad base for comparisons with the fossil grains. Affinities of the fossil grains within the Palmae are considered, both in a systematic context, and in the light of their palaeo- and recent geography, climate and ecology. The two monosulcate forms are compared to the fossil form-genus Palmaepollenites. One form is compared to P. kutchensis which has a well-defined Eocene plant-geographical province, spanning the Indian plate and the Southeast Asian region west of Wallaces Line. Palmaepollenites kutchensis most closely compares to genera exhibiting relict distributions, emphasising an ancient lineage. The closest matches are confined to Pacific island (Pritchardia, Lepidorrachis) or to New Caledonia genera (Basselinia, Burretiokentia). Morphological, ecological and plant geographical data suggest a probable affinity with the subtribe Iguanurinae of the tribe Areceae. The source taxon of Palmaepollenites kutchensis probably evolved on the Indian plate in the Paleocene, or possibly the Late Cretaceous, and migrated into Southeast Asia following collision with Asia in the Middle Eocene. Due to drier climates in the Oligocene it became sparse in the Indonesian region, and subsequently became extinct. The third pollen type is referred to Dicolpopollis malesianus. It closely compares with pollen of some species in the genera Calamus and Ceratolobus of subtribe Calaminae: Calamoideae.

Triporate pollen in the Arecaceae

Triapertury is rare in monocotyledons. The well-defined, regularly spaced, circular porate apertures that occur in Arecaceae: Areca klingkangensis from Borneo, and species of the West African genus Sclerosperma, appear to be unique in monocotyledons. There is evidence to suggest that tripory in Arecaceae has been derived from trichotomosulcy, although in Areca equatorial zonosulcy may have an important role. The apical triporate, and zonosulcate pollen of Areca are described, as well as examples of mono- and trichotomosulcate pollen within the genus. The sub-apical distal triporate pollen of Sclerosperma gilletii and S. mannii are described. Notably, in Sclerosperma pollen, aperture position at post-meiotic tetrad stage follows the rare ‘Garsides rule’ (four groups of three apertures), previously only demonstrated for Proteaceae and Olacaceae. Possible reasons for the occurrence of these rare triporate pollen phenomena in palms are considered. The bearing this may have on the transition from the distal polar position of the single sulcus, to the radial symmetry of the triaperturate condition in many dicotyledons is discussed in comparison with other examples of triapertury in monocotyledons.

A revision of Endostemon (Labiatae)

Summary. The genus Endostemon N.E.Br., widespread in tropical Africa and with one species in India, is revised and 18 species, placed in 4 sections, are recognized. One new species, Endostemon albus A. J. Paton, Harley & M. M. Harley, and two new sections, sects Oblongi Ayob. ex A. J. Paton, Harley & M. M. Harley & Leucosphaeri A. J. Paton, Harley & M. M. Harley are described. Endostemon leucosphaerus (Briq.) A. J. Paton, Harley & M. M. Harley is transferred into Endostemon from Erythrochlamys Briq. The circumscription of Endostemon is discussed and the morphological and palynological differences between Endostemon and related genera are illustrated. Endostemon can be distinguished from related genera by its short, villous anthers which are attached to the corolla just below the throat, a small shield-like swelling near the base of the style just above the nutlets and by the pollen having short colpi and alternately wide and narrow mesocolpia. The phytogeography of the genus is discussed. There are two centres of diversity, Angola and the Somalia-Masai region, each having different components.

Pollen morphology and systematics of Burseraceae

The Burseraceae are a medium‐sized family in which 18 genera are currently recognised. They are the subject of a long‐term project to describe the pollen morphology from light, scanning electron and transmission electron microscopy. The pollen morphology of tribe Protieae has been published, as well as an account of the pollen of the African taxa in the family. Pollen data for the other two tribes, Bursereae and Canarieae, are more or less complete. The pollen of all the genera have been examined, with the exception of the recently described Pseudodacryodes Pierlot for which, currently, there is no pollen material available. This paper summarises the results. There is considerable variation in exine and aperture features between, and occasionally within, the genera and 14 major pollen types are defined, including two previously undescribed types: ‘Canarium oleiferum’ and ‘Canarium gracile’. The distribution of pollen characteristics throughout the family is compared with previously published tribal and subtribal groupings, as well as with current ideas of generic relationships from molecular analyses. Comparisons show notable congruence of pollen data with molecular data. To some extent pollen morphology is different for each of the subtribes. Nevertheless, there are some notable exceptions, for example, the pollen of Garuga and Boswellia are remarkably similar, although Garuga has been included, somewhat tenuously, in tribe Protieae, and Boswellia is included in tribe Bursereae, subtribe Boswelliinae. In a recent molecular tree Garuga and Boswellia appear to be closely related, and this supports the conclusion, based on several macromorphological characters as well as pollen, that Garuga should be transferred to tribe Bursereae.