Lisa M. Campbell

A Phylogeny of the Monocots, as Inferred from rbcL and atpA Sequence Variation, and a Comparison of Methods for Calculating Jackknife and Bootstrap Values

Abstract A phylogenetic analysis of the monocots was conducted on the basis of nucleotide sequence variation in two genes (atpA, encoded in the mitochondrial genome, and rbcL, encoded in the plastid genome). The taxon sample of 218 angiosperm terminals included 177 monocots and 41 dicots. Among the major results of the analysis are the resolution of a clade comprising four magnoliid lineages (Canellales, Piperales, Magnoliales, and Laurales) as sister of the monocots, with the deepest branch within the monocots between a clade consisting of Araceae, Tofieldiaceae, Acorus, and Alismatales, and a clade that includes all other monocots. Nartheciaceae are placed as the sister of Pandanales, and Corsiaceae as the sister of Liliales. The Triuridaceae, represented by three genera, including Lacandonia, are resolved as monophyletic and placed in a range of positions, generally within Pandanales. Dasypogonaceae and Arecaceae diverge sequentially from a clade that includes all other commelinid taxa, and within the latter group Poales s. lat. are sister of a clade in which Zingiberales and Commelinales are sisters. Within Poales s. lat., Trithuria (Hydatellaceae) and Mayaca appear to be closely related to some or all elements of Xyridaceae. A comparison was conducted of jackknife and bootstrap values, as computed using strict-consensus (SC) and frequency-within-replicates (FWR) approaches. Jackknife values tend to be higher than bootstrap values, and for each of these methods support values obtained with the FWR approach tend to exceed those obtained with the SC approach.

Ordinal and familial relationships of Ranunculid genera

A morphological-based cladistic analysis was conducted on 116 ingroup taxa and 5 outgroups coded for 109 characters and 192 apomorphic character states. Ranunculid genera are better organized as the two orders Lardizabalales and Ranunculales, rather than Ranunculales and Papaverales of contemporary systems. Within Lardizabalales, the genus Decaisnea is segregated as a new family, in contrast to Sargentodoxa, which is maintained within Lardizabalalceae. The Berberidaceae and Menispermaceae are early branches of Ranunculales, which is primitively woody. Hydrastidaceae (including Glaucidium), Papaveraceae, and Ranunculaceae form a herbaceous clade of derived Ranunculales. The Papaveraceae subfamilies Platystemonoideae, Papaveroideae, and Eschscholzioideae are early branches, whereas Pteridophylloideae, Hypoecoideae, and Fumarioideae are derived. The Chelidonioideae are transitional and paraphyletic and therefore, a new subfamily is recognized for Glaucium and Dicranostigma. The Ranunculaceae subfamily lsopyroideae is a first branch, and Helleboroideae and Ranunculoideae are sister graups. Within lsopyroideae, the Aquilegieae is a first branch, and lsopyreae and Coptidae (including Dichocarpum and Thalictrum) are sister groups. Within Helleboroideae, the Caltheae is a first branch, and Helleboreae (including Nigella) and Cimicifugeae (including Aconitum, Beesia, and Delphinium) are sister groups. Within Ranunculoideae, the Adonideae is a first branch, and Anemoneae and Ranunculeae are sister groups. Circaeaster and Kingdonia are sister groups and positioned as a first branch of the Anemoneae, and it is at least 7 steps less parsimonious to remove both from Ranunculaceae, and 14 steps longer to remove only Circaeaster. It is 10 steps less parsimonious to consider a Ranunculaceae ancestry for Paeonia, which is positioned in Dilleniales. The “ranunculidae” are paraphyletic because Ranunculales are closer to Dilleniales than to Lardizabalales.

Are mitochondrial genes useful for the analysis of monocot relationships

A phylogenetic analysis of monocots and related dicots was conducted, using a four-gene matrix consisting of two genes from the plastid genome (matK and rbcL) and two from the mitochondrial genome (atpA/atp1 and cob). The taxon sample includes 101 monocots and 36 dicots, and all four genes were sampled for all 137 taxa. Jackknife support was assessed for clades resolved by the four-gene analysis, and compared to support for the same clades by each of the four three-gene subset matrices, in order to quantify the degree to which each gene contributed to or detracted from support for each clade. Instances of positively and negatively correlated support for clades by genes of the same and different genomes were observed. In particular, the placement of Acorus within a clade that also includes Tofieldiaceae, Araceae, and Alismatales s.s., as opposed to its frequent placement as sister of all other monocots, is supported by atpA and matK. The results indicate that genes from the mitochondrial genome provide a unique test of relationships that have been inferred with plastid-encoded genes.

Floral colleters in Pleurothallidinae (Epidendroideae: Orchidaceae)

PREMISE OF THE STUDY The term colleter is applied to trichomes or emergences positioned close to developing vegetative and floral meristems that secrete a sticky, mucilaginous, and/or lipophilic exudate. Several ecological functions are attributed to these glands, but none are exclusive to colleters. Patterns of morphology and distribution of colleters may be valuable for systematics and phylogeny, especially concerning problematic and large groups such as the subtribe Pleurothallidinae, and are also essential to understand the evolution of these glands in Orchidaceae as a whole. METHODS We used scanning electron and light microscopy to examine the structure and occurrence of trichomes on bracts and sepals and in the invaginations of the external ovary wall (IEOW) in flowers in several developmental stages from species in seven genera. KEY RESULTS The exudate was composed of polysaccharides, lipophilic, and phenolic compounds. Colleters were secretory only during the development of floral organs, except for the glands in the IEOW that were also active in flowers at anthesis. After the secretory phase, fungal hyphae were found penetrating senescent trichomes. CONCLUSIONS Trichome-like colleters seem to be a widespread character in Epidendroideae, and digitiform colleters are possibly the common type in this subfamily. Mucilage from IEOW colleters may aid in the establishment of symbiotic fungi necessary for seed germination. The presence of colleters in the IEOW may be a case of homeoheterotopy, in which extrafloral nectaries that produce simple sugar-based secretions (as in other orchid species) have changed to glands that produce secretions with complex polysaccharides, as in Pleurothallidinae.

Pollen Morphology of Xyridaceae Systematic (Poales) and its Potential

Xyridaceae are a predominantly tropical family of five genera that exhibit two pollen morphologies often considered to be of taxonomic importance. Xyris comprises about 95% of the species and is characterized by medium to large, elliptic, sulcate pollen grains. The other pollen class is spheroidal grains without an evident aperture. Many of the species with spheroidal grains have remarkably large and ornamented pollen found to be species specific in earlier research. A scanning electron microscopy investigation of 23 taxa representing all genera with spheroidal pollen revealed new data to further distinguish the genera based on pollen characters. Reliable specific pollen characters need to be evaluated in a statistical study.

Xyridaceae of Viruá National Park, Roraima state, Brazil

A taxonomic treatment of the Xyridaceae in the Virua National Park is presented. Located in Roraima state, northern Brazil, the park comprises a mosaic of lowland vegetation types, including forests, wetlands, and one of the largest continuous areas of campinarana in the Brazilian Amazon Basin. Xyridaceae are represented in the park by 20 species in the genera Abolboda and Xyris. Although the four species of Abolboda are widespread, most of the Xyris species (75%) are endemic to Amazonian open vegetation formations, such as campinaranas and savannas. This study was based on field, herbarium, and scanning electron microscopy research. The taxonomic treatment includes identification keys to the genera and species, morphological descriptions, SEM images of seeds for Xyris species, iconography, geographic distribution and comments on the ecology of the species. The poorly known Xyris connosepala is synonymized in Xyris guianensis.

Collections in the Plant Research Laboratory of The New York Botanical Garden

The Plant Research Laboratory at The New York Botanical Garden maintains a variety of research samples for biodiversity studies. The collections are the products of botanical exploration, laboratory research, collaborations, and donations from the scientific community. These collections are enumerated, and information about herbarium voucher specimens, the history of the collections, and their current use is provided.

A new species of Securidaca (Polygalaceae) from sandstone outcrops in the Venezuelan Andes

A new species ofSecuridaca was found during the preparation of the Polygalaceae treatment for theNuevo Catálogo de la Flora de Venezuela.Securidaca fundacionensis, from La Fundación, in the Venezuelan Andes, is described, illustrated, and its morphological relationship with an allied species is discussed. This new species is similar toS. uniflora, but it differs by its terete branches; broadly ovate leaves; larger petioles, flowers, fruits; and flabellate-crested keel (abaxial) petal. An updated key to the 27 Venezuelan species ofSecuridaca is presented, and phytogeographical information about La Fundación is provided.ResumenUna nueva especie del géneroSecuridaca fue encontrada durante la elaboración del tratamiento de la familia Polygalaceae para elNuevo, Catálogo de la Flora de Venezuela.Securidaca fundacionensis, del sector La Fundación, estado Táchira, Andes de Venezuela, es descrita, ilustrada y sus relaciones morfológicas con su especie afín son discutidas.S. fundacionensis es similar aS. uniflora, sin embargo, difiere de esta especie por poseer las ramas teretes; las hojas ampliamente ovadas; los pecíolos, las flores, y los frutos más grandes; y la quilla (el pétalo inferior) con una cresta flabelada. Se presenta una clave actualizada para diferenciar las 27 especies del géneroSecuridaca presentes en Venezuela y información general acerca la fitogeografía del sector La Fundación.

Xyris irwinii (Xyridaceae), a new cerrado species from Goiás, Brazil

Xyris irwinii (Xyridaceae), a new species from the cerrado of Goiás, Brazil is described and illustrated. The distribution, phenology, and conservation status of the new species are presented, as well as a comparison of a complex of morphologically related cerrado species.ResumoUma nova espécie de Xyris irwinii (Xyridaceae) procedente do estado de Goiás, Brasil é descrita e ilustrada. A distribuição, fenologia e estado de conservação, da nova espéciese são apresentados, além de uma comparação com um complexo de espécies morfologicamente relacionados do cerrado.

Erratum to: Pollen Morphology of Xyridaceae (Poales) and its Systematic Potential

Xyridaceae are a predominantly tropical family of five genera that exhibit two pollenmorphologies often consideredtobe of taxonomic importance.Xyris comprises about 95% of the species and is characterized by medium to large, elliptic, sulcate pollen grains. The other pollen class is spheroidal grains without an evident aperture. Many of the species with spheroidal grains have remarkably large and ornamented pollen found to be species specific in earlier research. A scanning electron micros- copy investigation of 23 taxa representing all genera with spheroidal pollen revealed new data to further distinguish the genera based on pollen characters. Reliable specific pollen characters need to be evaluated in a statistical study.