Murderous plants: Victorian Gothic,Darwin and modern insights into vegetable carnivory

Darwin's interest in carnivorous plants was in keeping with the Victorian fascination with Gothic horrors, and his experiments on them were many and varied, ranging from what appears to be idle curiosity (e.g. what will happen if I place a human hair on a Drosera leaf?) to detailed investigations of mechanisms. Mechanisms for capture and digestion of prey vary greatly among the six (or more) lineages of flowering plants that have well‐developed carnivory, and some are much more active than others. Passive carnivory is common in some groups, and one, Roridula (Roridulaceae) from southern Africa, is so passively carnivorous that it requires the presence of an insect intermediate to derive any benefit from prey trapped on its leaves. Other groups not generally considered to be carnivores, such as Stylidium (Stylidiaceae), some species of Potentilla (Rosaceae), Proboscidea (Martyniaceae) and Geranium (Geraniaceae), that have been demonstrated to both produce digestive enzymes on their epidermal surfaces and be capable of absorbing the products, are putatively just as ‘carnivorous’ as Roridula. There is no clear way to discriminate between cases of passive and active carnivory and between non‐carnivorous and carnivorous plants – all intermediates exist. Here, we document the various angiosperm clades in which carnivory has evolved and the degree to which these plants have become ‘complete carnivores’. We also discuss the problems with definition of the terms used to describe carnivorous plants. © 2009 The Linnean Society of London, Botanical Journal of the Linnean Society, 2009, 161 , 329–356.     

A phylogenetic classification of the land plants to accompany APG III

A formal classification of the land plants that is compatible with the APG III classification is proposed. Previous classifications inflated taxonomic ranks, particularly of the angiosperms. If the major clades of green algae are recognized as classes, then all land plants, the embryophytes, should be included in a single class, here recognized as Equisitopsida. Accordingly, the 16 major clades of land plants, including the angiosperms, should all be recognized as subclasses, the angiosperms as Magnoliidae. Major clades within the angiosperms are then recognized as superorders. This classification still uses a few informal categories (e.g. eudicots, lamiids, etc.) within the angiosperms because this is convenient. Two new names are established: Amborellanae and Austrobaileyanae. © 2009 The Linnean Society of London, Botanical Journal of the Linnean Society, 2009, 161 , 122–127.     

Anatomical and molecular systematics of Asteliaceae and Hypoxidaceae

The astelioid group of asparagoid lilies (Lilianae - Asparagales) comprises Hypoxidaceae, Asteliaceae, Blandfordia and Lanaria. New information is presented on astelioid anatomy, together with a review of other systematic characters. These data are analysed in the context of recent evidence from rbc L nucleotide sequences that astelioids are related to orchids, and that astelioids and orchids (plus Alania and Borya ) form a clade that is sister to all other asparagoid taxa. Hypoxidaceae and Asteliaceae differ from each other in several respects, but there are certain characters linking the two families, notably branched hairs and mucilage canals, unusual characters in Lilianae. Family diagnoses are upheld, but the precise relationships of Blandfordia and Lanaria are still poorly supported within the astelioid clade.     

Molecular phylogenetics and evolution of Orchidinae and selected Habenariinae (Orchidaceae)

Internal transcribed spacer (ITS nuclear rDNA) data have been obtained from 190 terrestrial orchid species, encompassing all genera and the great majority of the widely recognized species of Orchidinae, a heterogeneous selection of species of Habenariinae, and single species of Satyriinae and Disinae (the latter serving as outgroup). The resulting parsimony‐based phylogeny reveals 12 well‐resolved clades within the Orchidinae, based on Anacamptis s.l., Serapias, Ophrys, Steveniella–Himantoglossum s.l. (including ‘Comperia’ and ‘Barlia’, most species being 2n = 36), Neotinea s.l., Traunsteinera–Chamorchis, Orchis s.s., Pseudorchis–Amerorchis–Galearis–Neolindleya–Platanthera s.l. (most 2n = 42), Dactylorhiza s.l., Gymnadenia s.l. (most 2n = 40, 80), Ponerorchis s.l.–Hemipilia s.l.–Amitostigma–Neottianthe, and Brachycorythis (most 2n = 42). Relationships are less clearly resolved among these 12 clades, as are those within Habenariinae; the subtribe appears either weakly supported as monophyletic or as paraphyletic under maximum parsimony, and the species‐rich genus Habenaria is clearly highly polyphyletic. The triphyly of Orchis as previously delimited is confirmed, and the improved sampling allows further generic transfers to Anacamptis s.l. and Neotinea s.l. In addition, justifications are given for: (1) establishing Steveniella as the basally divergent member of an appreciably expanded Himantoglossum that incorporates the former genera ‘Barlia’ and ‘Comperia’, (2) reuniting ‘Piperia’ with a broadly defined Platanthera as section Piperia, necessitating ten new combinations, (3) broadening Ponerorchis to include Chusua, and Hemipilia to include single ‘orphan’ species of Ponerorchis and Habenaria, and (4) recognizing ‘Gymnadenia’camtschatica as the monotypic Neolindleya camtschatica within the Pseudorchis～Platanthera clade. Few further generic transfers are likely in Orchidinae s.s., but they are anticipated among habenariid genera, on acquisition of additional morphological and molecular evidence; one probable outcome is expansion of Herminium. Species‐level relationships are also satisfactorily resolved within most of the major clades of Orchidinae, with the notable exceptions of Serapias, the derived sections of Ophrys, Himantoglossum s.s., some sections within Dactylorhiza, the former genus ‘Nigritella’ (now tentatively placed within Gymnadenia s.l.), Hemipilia s.l., and possibly Ponerorchis s.s. Relationships among the 12 major clades broadly accord with bona fide records of intergeneric hybridization. Current evidence supports the recently recognized 2n = 36 clade; it also indicates a 2n = 40 clade that is further diagnosed by digitate root‐tubers, and is derived relative to the recently recognized clade of exclusively Asian genera (Ponerorchis s.l.–Hemipilia s.l.–Amitostigma–Neottianthe). This in turn appears derived relative to the Afro‐Asiatic Brachycorythis group; together, these two clades identify the plesiomorphic chromosome number as 2n = 42. If the African genus Stenogolottis is correctly placed as basally divergent within a monophyletic Habenariinae, the tribe Orchideae and subtribes Orchidinae and Habenariinae could all have originated in Africa, though in contrast the Asiatic focus of the basally divergent members of most major clades of Orchidinae suggests an Asiatic radiation of the subtribe. Morphological characters informally ‘mapped’ across the molecular phylogeny and showing appreciable levels of homoplasy include floral and vegetative pigmentation, flower shape, leaf posture, gynostemium features, and various pollinator attractants. Qualitative comparison of, and reciprocal illumination between, degrees of sequence and morphological divergence suggests a nested set of radiations of progressively decreasing phenotypic magnitude. Brief scenarios, both adaptive and non‐adaptive, are outlined for specific evolutionary transitions. Recommendations are made for further species sampling, concentrating on Asian Orchidinae (together with the Afro‐Asiatic Brachycorythis group) and both Asian and Southern Hemisphere Habenariinae, and adding plastid sequence data. Taxonomic changes listed are: Anacamptis robusta (T.Stephenson) R.M.Bateman, comb. nov. , A. fragrans (Pollini) R.M.Bateman, comb. nov. , A. picta (Loiseleur) R.M.Bateman, comb. nov. , Neotinea commutata (Todari) R.M.Bateman, comb. nov. , N. conica (Willdenow) R.M.Bateman, comb. nov. , Platanthera elegans Lindley ssp. maritima (Rydberg) R.M.Bateman, comb. nov. , P. elegans Lindley ssp. decurtata (R.Morgan & Glicenstein) R.M.Bateman, comb. nov. , P. elongata (Rydberg) R.M.Bateman, comb. nov. , P. michaelii (Greene) R.M.Bateman, comb. nov. , P. leptopetala (Rydberg) R.M.Bateman, comb. nov. , P. transversa (Suksdorf) R.M.Bateman, comb. nov. , P. cooperi (S.Watson) R.M.Bateman, comb. nov. , P. colemanii (R.Morgan & Glicenstein) R.M.Bateman, comb. nov. , P. candida (R.Morgan & Ackerman) R.M.Bateman, comb. nov. and P. yadonii (R.Morgan & Ackerman) R.M.Bateman, comb. nov. © 2003 The Linnean Society of London, Botanical Journal of the Linnean Society, 2003, 142 , 1–40.