Hairs and water uptake
Lux and Kopunec studied uptake of tritium-labelled water through A. myriostigma and A. ornatum surfaces. They compared surfaces with and without hairs. In the water vapour experiment, uptake through hairy surfaces was almost ten times greater. Liquid water uptake was about a hundred times more efficient than uptake from the gas phase, and bare surfaces could take it up faster. [Lux and Kopunec 1992]
Experiments used artificially controlled conditions, sealed roots and a saturated atmosphere. Temperatures were about 40–41°C for vapour tests and 29–31.5°C for liquid water tests. The result confirms possible uptake through the stem surface. It does not measure the whole plant's water balance during an ordinary night in nature. Mechanical hair removal may also have injured the surface and affected results. [Lux and Kopunec 1992]
Seeds on water
Sánchez-Salas and colleagues compared A. capricorne and A. ornatum. Seeds were collected from 35 mother plants of each species. The buoyancy study used five replicates of ten seeds, and the germination experiment five replicates of twenty seeds per treatment. Tests lasted 30 days. [Sánchez-Salas et al. 2012]
After a month, 40% of A. capricorne seeds with the outer layer of funicular remains intact stayed afloat, and 70% after its removal. For A. ornatum, the values were 90% and 100% respectively. Meanwhile, A. ornatum germination remained below 30% in all treatments and below 5% under submergence or a thin water layer. Buoyancy may favour transport during floods, while germination success depends on another set of conditions. [Sánchez-Salas et al. 2012]
Nazwa quadricostatum
Montanucci and Kleszewski compared name history, type material and Jaumave valley population features. The proportion of four-ribbed plants in older imports may reflect collectors' selection. In natural populations studied, five-ribbed plants were frequent or dominant. Results explain why rib number cannot be the only subspecies criterion. [Montanucci and Kleszewski 2019]
The meaning of nudum and tulense
The nudum study showed continuous hair-cover variation and no clearly separate morphological and geographical feature set. The authors favoured treating bare plants as a form within broader variation. For the atlas, this preserves a useful appearance term without creating another accepted subspecies. [Montanucci and Kleszewski 2020] [2-WWW]
The 2021 paper compared nine populations treated as the nominate subspecies and six in the tulense group. It found differences in growth form, flowers and seeds, with some populations harder to classify unequivocally. In the database state adopted here, POWO does not accept tulense as a separate subspecies. Both treatments are recorded with their sources. [Montanucci and Kleszewski 2021] [2-WWW]
Pochodzenie coahuilense
In 2024, Montanucci compared vegetative and reproductive features and crossing results. His multivariate analysis used 15 features, with 22 A. capricorne, 26 A. coahuilense, four A. myriostigma in the narrower nominate sense and 29 tulense plants. Unequal group sizes are important interpretive context. [Montanucci 2024]
The mosaic of similarities supports historical hybridisation. Some A. coahuilense features resemble A. myriostigma, others A. capricorne. The author identifies a need for further research. This finding is compared with the 2015 plastid analysis, which places coahuilense in a different lineage from myriostigma. Morphological and plastid data describe different parts of this history. [Vázquez-Lobo et al. 2015] [Montanucci 2024]
Climate and conservation
The 2016 niche modelling used MaxEnt and A1B and A2 emission scenarios. Climate in 1950–2000 was the baseline. The period called 2020 in the paper covered 2010–2039, and 2050 covered 2040–2069. These are historical model projections in the atlas. They do not measure population losses in 2020 or represent a current forecast prepared in 2026. [Carrillo-Angeles et al. 2016]
The authors identified particular vulnerability of A. asterias and A. ornatum under the scenarios used. Habitat loss, illegal collection and limitations on population renewal also matter. The material covered four species, so results were not automatically extended to A. caput-medusae and A. coahuilense as separately analysed units. [Carrillo-Angeles et al. 2016]
Historical divisions of the genus
The 2009 account organises names of groups within the genus and discusses Digitostigma's position. It helps interpret old labels and classifications. Divisions based on fruit, seed and other features were later compared with molecular data. In the atlas, older groups remain part of systematic history, with the source year clearly stated. [Montanucci 2009] [Vázquez-Lobo et al. 2015] [Anonim b.d.v]