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A new Schizanthus species from northern Chile is described and illustrated. Schizanthus nutantiflorus was discovered based on recent collections made during unusual rain events in the Atacama Desert in 2015. The new species is distinguished morphologically from other Schizanthus species from northern Chile by its short corolla tube, with a distinct upper lip arrangement and colour, having the longest lower lip, and downward-facing flowers. Additionally, the reinstatement of Schizanthus fallax is proposed. By using both nDNA and cpDNA, phylogenetic relationships among all species of Schizanthus were investigated. Molecular and field observations, as well as an exhaustive morphological revision of fresh material and herbarium specimens, supports the segregation of Schizanthus with short corolla tubes from northern Chile into three species. We propose that, in order to fully understand both the taxonomy and evolution of Schizanthus, an integrative framework encompassing molecular, ecological, and morphological data should be carried out. Information on distribution, habitat, informal conservation status, as well as taxonomic notes and illustrations are provided. In addition, an updated key for the species of Schizanthus from northern Chile is given. [ABSTRACT FROM AUTHOR]

Carbon, nitrogen, and phosphorus (C, N, P) stoichiometry influences the growth of plants and nutrient cycling within ecosystems. Indeed, elemental ratios are used as an index for functional differences between plants and their responses to natural or anthropogenic variations in nutrient supply. We investigated the variation in growth and elemental content of the rootless terrestrial bromeliad Tillandsia landbeckii, which obtains its moisture, and likely its nutrients, from coastal fogs in the Atacama Desert. We assessed (1) how fog nutrient supply influences plant growth and stoichiometry and (2) the response of plant growth and stoichiometry to variations in nutrient supply by using reciprocal transplants. We hypothesized that T. landbeckii should exhibit physiological and biochemical plastic responses commensurate with nutrient supply from atmospheric deposition. In the case of the Atacama Desert, nutrient supply from fog is variable over space and time, which suggests a relatively high variation in the growth and elemental content of atmospheric bromeliads. We found that the nutrient content of T. landbeckii showed high spatio-temporal variability, driven partially by fog nutrient deposition but also by plant growth rates. Reciprocal transplant experiments showed that transplanted individuals converged to similar nutrient content, growth rates, and leaf production of resident plants at each site, reflecting local nutrient availability. Although plant nutrient content did not exactly match the relative supply of N and P, our results suggest that atmospheric nutrient supply is a dominant driver of plant growth and stoichiometry. In fact, our results indicate that N uptake by T. landbeckii plants depends more on N supplied by fog, whereas P uptake is mainly regulated by within-plant nutrient demand for growth. Overall, these findings indicate that variation in fog nutrient supply exerts a strong control over growth and nutrient dynamics of atmospheric plants, which are ubiquitous across fog-dominated ecosystems. [ABSTRACT FROM AUTHOR]

Aim In deserts, past climate change (and particularly past rainfall variability) plays a large role in explaining current plant species distributions. We ask which species were most and which were least affected by changes in rainfall during the late Quaternary in northernmost Chile. Location Quebrada La Higuera ( QLH; 18° S), a shallow canyon that cuts east-west through the western Andean precordillera of northern Chile, connecting the Altiplano with the hyperarid Atacama Desert. Methods We collected and dated 22 rodent middens from elevations of 3100-3500 m in QLH. These were analysed for identifiable plant macrofossils and pollen. We also measured chinchilla rat ( Abrocoma cinerea) faecal pellets in the youngest middens to explore how they relate to past ecological and climatic change. Results The three oldest middens dated to more than 37 ka (thousand calibrated 14C years), four middens dated to 14.4-11.6 ka, and fifteen middens spanned the last 650 years. During all the intervals examined, extralocal species (those found today at higher elevations and indicative of positive rainfall anomalies) were present at our midden sites. In the youngest interval, Parastrephia pollen (indicating increased rainfall) increased abruptly at ad 1760 and remained high until the mid-1800s. This increase was also seen in our faecal pellet record. Main conclusions Extralocal species were prevalent in late Pleistocene middens at lower elevations when the climate was wetter. When combined with other regional midden records, we postulate that many species found today in the Altiplano were displaced to lower elevations during the late Pleistocene. The recent large-scale mortality documented among arboreal cactus populations along the present upper margins of the Atacama suggests that these are relict populations that are likely to have flourished during a wetter period in the early 1800s. [ABSTRACT FROM AUTHOR]