Topic
Eriosyce
About: Eriosyce is a research topic. Over the lifetime, 12 publications have been published within this topic receiving 113 citations.
Papers
TL;DR: Stem orientation and morphology were investigated for 14 species of cacti in Chile, Ecuador, Mexico, and the United States as discussed by the authors, and it was found that the orientation increased PAR absorption at times of the year favorable for growth.
Abstract: Stem orientation and morphology were investigated for 14 species of cacti in Chile, Ecuador, Mexico, and the United States. The interception of photosynthetically active radiation (PAR) was specifically considered for cladodes (flattened stems) of platyopuntias, for tilted cylindrical stems, and in the presence of surrounding vegetation. Terminal cladodes of Opuntia chlorotica had a statistically significant tendency to face north- south at specific sites in the Mojave desert and east-west in the Sonoran desert. There was also a tendency for cladodes of three varieties of 0. echios in the Galapagos Islands, Ecuador, to face east- west, while three times more cladodes of 0. stricta var. dillenii faced within 15? of east-west than within 150 of north-south in Florida. In all cases, the orientation increased PAR absorption at times of the year favorable for growth. The longitudinal axes of ceroid cacti with multiple stems were vertical in both the northern (Car- negiea gigantea, Lemaireocereus thurberi, and Lophocereus schottii) and southern (Trichocereus chilensis) hemispheres. However, the longitudinal axes of barrel-shaped cacti with single cylindrical stems tended to tilt southward in the northern hemisphere (Ferocactus acanthodes, F. covillei, F. viridescens, and F. wislizenii) and northward in the southern hemisphere (Copiapoa cinerea var. columna-alba, C. lembckei, and Eriosyce ceratistes). Although equatorial tilting can increase the temperature of the apical region for certain cacti in the wintertime, for other species it has relatively little influence on minimum or maximum stem temperatures. Also, it tends to reduce the total amount of PAR intercepted by the sides of the stem. Hence, equatorial tilting may not be of adaptive advantage for all cacti. The maximum stem height of 0. echios varied 2-fold in a series of communities extending over 16 km on Santa Cruz Island in the Galapagos Islands, and the maximum height of T. chilensis varied 4-fold over 12 km in central Chile. Changes in stem height were positively correlated with changes in the height of the surrounding vegetation (r > .98) and negatively correlated with PAR in the vertical planes of the stems at 2 m (r 'S -.96). The diurnal change in tissue acidity of these Crassulacean-acid- metabolism (CAM) plants was 90% light-saturated for a total daily PAR of about 20 mol of quanta- m- d-l, which is approximately the average PAR that unshaded vertical stems would receive on clear days. Hence, the increase in height of these cacti accompanying increases in height of the surrounding vegetation helps to insure that they receive adequate PAR. In fact, for these and other cacti, PAR is often limiting for CO2 uptake, even in the high-radiation environment of deserts.
47 citations
TL;DR: A computer model predicted the minimum stem surface temperature, which generally occurred at the apex, for various species of cacti under a particular set of environmental conditions, and based on stem mass, spines, and apical pubescence for the four Ferocactus species found in the southwestern United States, F. acanthodes had the highest minimum apical temperatures and hence was predicted to range the furthest north.
Abstract: A computer model predicted the minimum stem surface temperature, which generally occurred at the apex, for various species of cacti under a particular set of environmental conditions. Based on stem mass, spines, and apical pubescence for the four Ferocactus species found in the southwestern United States, F. acanthodes had the highest minimum apical temperatures and hence was predicted to range the furthest north, F. wizlizenii next, then F. covillei, and finally F. viridescens, in agreement with field observations. Direct measurement of apical temperatures at night showed that F. viridescens was about 2°C colder than a side-by-side F. acanthodes, in agreement with the model. The simulated apical temperature of Trichocereus chilensis increased about 0.3°C for each 50 cm increase in height up to 2 m; observations at a high elevation site in central Chile showed that the freezing damage progressively halved over this sequence of height intervals. The upper elevational limit of Eriosyce ceratistes and T. chilensis at different latitudes from 29°S to 35°S indicated that the populations were responsive to changes of only 0.1°C. Such temperature sensitivities underscore the importance of morphological differences in establishing the low temperature limits on the ranges of cacti in particular and plants in general.
34 citations
TL;DR: A phylogeny‐informed infrageneric classification of the genus Eriosyce is presented and new combinations are proposed to update the nomenclature of species and sections, and some past taxonomic proposals have low phylogenetic support and should no longer be used.
Abstract: Eriosyce is one of most species‐rich genera within Notocacteae (Cactaceae) harboring a variety of stem and flower morphologies, and fruits with basal abscission. The lack of a well‐sampled molecular phylogeny contributes to the current taxonomic instability of the genus, where its circumscription and infrageneric classification has been questioned. Specimens of Eriosyce (63 taxa) plus 19 outgroups were analyzed through sequencing three plastid noncoding introns (rpl32‐trnL, trnL‐trnF, trnH‐psbA), one plastid gene (ycf1), and one nuclear gene (PHYC). Individual markers and concatenated matrices were analyzed using maximum likelihood and Bayesian approaches. Phylogenetic analyses strongly support the monophyly of Eriosyce s.l. Furthermore, seven clades within Eriosyce s.l. were defined based on supported branches, although one of them was weakly supported. Our results suggest that some past taxonomic proposals have low phylogenetic support and should no longer be used, e.g., based on their scattered positions in the phylogenetic reconstruction, several infraspecific taxa appear unrelated to the typical form of the species in which they had been placed. We present a phylogeny‐informed infrageneric classification of the genus Eriosyce, and new combinations are proposed to update the nomenclature of species and sections.
15 citations
TL;DR: The localization and distribution of Eriosyce islayensis, E. iquiquensis and E. caligophila sp.nov.
Abstract: This study shows the localization and distribution of Eriosyce islayensis, E. iquiquensis and E. caligophila sp.nov. along the northernmost coast of Chile. It describes the geographical locations of the populations, together with demographic, phenological and ecological aspects. The populations of E. islayensis were found to be dead. Living populations of E. iquiquensis occurred only in the southern part of the study area. The population of E. caligophila sp.nov. is restricted to only one locality.
7 citations
TL;DR: Rimacactus, a new genus within subtribe Borzicactinae of the Cactaceae, is named for the species formerly known as Eriosyce laui Lüthy, and its morphology and systematics are discussed.
Abstract: Rimacactus, a new genus within subtribe Borzicactinae of the Cactaceae, is named for the species formerly known as Eriosyce laui Luthy.A detailed description of a cultivated plant is provided, and its morphology and systematics are discussed.
5 citations
Related Topics (5)
Performance Metrics
| Year | Papers |
|---|---|
| 2019 | 1 |
| 2018 | 2 |
| 2017 | 1 |
| 2015 | 1 |
| 2011 | 2 |
| 2005 | 2 |