Research Article |
Corresponding author: María Virginia Palchetti ( vpalchetti@imbiv.unc.edu.ar ) Corresponding author: Andrés Moreira-Muñoz ( andres.moreira@pucv.cl ) Academic editor: Leandro Giacomin
© 2021 María Virginia Palchetti, Juan José Cantero, Vanezza Morales-Fierro, Gloria E. Barboza, Andrés Moreira-Muñoz.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Palchetti MV, Cantero JJ, Morales-Fierro V, Barboza GE, Moreira-Muñoz A (2021) Living in extreme environments: distribution of Lycium humile (Solanaceae), an endemic halophyte from the Altiplano-Puna region, South America. PhytoKeys 185: 1-15. https://doi.org/10.3897/phytokeys.185.71377
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Very few Solanaceae species are able to grow in saline soils; one of them is Lycium humile. This species is endemic to the Altiplano-Puna region (Central Andes, South America) where there are multiple extreme environmental conditions such as hypersaline soils. Here we present an updated description and distribution of L. humile including its new record for Bolivia at the edges of “Salar de Uyuni”, the largest salt flat in the world; we discuss its ecological role in saline environments by analyzing soil salinity and cover-abundance values of the studied sites. According to IUCN criteria, we recommend a category of Least Concern for L. humile, but the growing development of lithium mining in saline environments of the Altiplano-Puna region may potentially threaten exclusive communities.
Andes, Argentina, Bolivia, Chile, conservation status, new record, saline soil, salt-tolerant
Lycium L. is the only member of tribe Lycieae (Atropina clade, Solanaceae;
The Altiplano-Puna region of the Central Andes is considered a cold desert, with high elevation (3700 m average elev.), extreme temperatures (which can reach –30 °C) and daily temperature fluctuations, low and irregular precipitation (even < 50 mm per year), high evaporation and UV radiation, and low nutrient availability (
As part of a study of salt tolerance in South American Solanaceae species, we carried out extensive explorations in the Altiplano-Puna region to check the presence and abundance of Solanaceae, in extreme saline environments. Therefore, the aims of this study are: 1) to update the distribution and description of L. humile, 2) to document a new record for Bolivia, and 3) to discuss the ecological role of this species in saline environments of the Altiplano-Puna region.
Field collections were performed in Argentina, Bolivia and Chile during 2015 to 2019, comprising expeditions carried out in Jujuy, Salta and Catamarca provinces (Argentina), Antofagasta region (Chile) and Potosí department (Bolivia), between 2000 and 4000 m elevation.
Species description was based on Lycium monograph (
Distribution was plotted using QGIS 2.8 (
Local abundance of L. humile and different edaphic variables (pH, electric conductivity [EC], Na+, Cl–, Ca2+ and Mg2+) were evaluated in seven sites of Argentina, where geographic coordinates were recorded; voucher specimens were collected and deposited at CORD herbarium. Local abundance was calculated as estimated L. humile cover percentage in thirty 10 m × 10 m plots at each site. Fifteen random soil sub-samples at 0–20 cm depth were taken from each site and pooled as a composite sample for saturation extract analysis (
The conservation status was assessed applying the
Chile. [Antofagasta: Province of Antofagasta], Ad aquas [Profetas], December [1853]–January [1854], R.A. Philippi s.n., pro parte (lectotype, inadvertently designated as ‘type’ by
Dwarf shrubs, prostrate or ascending, up to 20 cm high, often forming dense and extensive mats, over 5 m. Subterranean organs well-developed with tangled and woody roots and rhizomes. Stems grayish-yellow, unarmed, glabrous, much branched, with slightly arched aerial branches and some stoloniferous branches. Leaves alternate or fasciculate, succulent, obovate or spatulate, light green, 2–16 mm long, 1–4 mm wide, glabrous or with occasionally glandular trichomes, sessile. Flowers 5-merous (rarely 4- or 6-merous), solitary, perfect; calyx tubular, zygomorphic, glabrous, bilabiate or irregularly toothed, the tube 3–5 mm long, the lobes sub-triangular, 1–2 mm long, ciliate at the margins; corolla white, sometimes with purple lines within, narrowly infundibuliform to tubular, barely zygomorphic, glabrous outside, the tube 12–15.5 mm long, 3–3.5 mm wide, glabrescent near the insertion of the stamens inside, the lobes 2.5–3.5 mm long, 2.5–4 mm wide, ovate, with sparse cilia on the edge; stamens inserted at 2/3 from the base, at different levels, filaments unequal in length, some exserted, others included or barely exserted, with few simple hairs at their bases; ovary with prominent red-orange nectary at the base, style exserted or scarcely exserted. Berry subglobose, ca. 7–8 mm in diameter, blackish; seeds irregular, polyhedral, pale brown, up to 25 per fruit, the episperm smooth, without marked cells.
Flowering late September-March; fruiting late December-April.
Bálsamo finito, ch’ampita (
Lycium humile is distributed in the Andean region, southern South America (Argentina, Bolivia and Chile), at 2300–4100 m elevation (Fig.
The species preferentially grows in saline clay soils, and less frequently in sandy soils. It is commonly found in saline mudflats of salars (Fig.
According to the IUCN criteria (
Edaphic variables of saturated paste extract, bare soil and soil covered by L. humile for each study site. Specimen vouchers were deposited at CORD.
Site | Geographical coordinates | Specimen voucher | Edaphic variables | Bare soil (%) | Soil covered by L. humile (%) | |||||
Cl–(mg/L) | Ca2+ (mg/L) | Mg2+ (mg/L) | Na+ (mg/L) | pH | EC (dS/m) | |||||
Laguna Pasto Ventura | 26°44.0133'S; 67°9.4433'W | Barboza G.E. et al. 4725 | 1134.0 | 48.0 | 14.0 | 2144.1 | 7.4 | 99.2 | 15.6 | 16.9 |
Carachi Pampa | 26°26.0633'S; 67°29.38'W | Barboza G.E. et al. 4304 | 14512.4 | 1500.0 | 1518.8 | 12000.0 | 9.8 | 112.5 | 70.6 | 17.7 |
Salar de Antofalla | 25°31.93'S; 67°34.855'W | Barboza G.E. et al. 4313 | 23181.5 | 480.0 | 60.8 | 14875.0 | 8.7 | 160.0 | 52.8 | 39.2 |
Salar del Hombre Muerto | 25°27.8017'S; 67°10.37'W | Barboza G.E. et al. 4309b | 31311.0 | 1800.0 | 741.2 | 17125.0 | 8.3 | 182.5 | 55.5 | 34.4 |
Salar Tolar Grande | 24°35.575'S; 67°23.4783'W | Barboza G.E. et al. 4749 | 3200.0 | 25.0 | 4.0 | 20281.7 | 7.9 | 203.3 | 61.5 | 12.8 |
Los Colorados | 24°35.4217'S; 67°8.2083'W | Barboza G.E. et al. 4347 | 45191.5 | 440.0 | 2940.3 | 25375.0 | 8.5 | 290.0 | 82.0 | 28.1 |
Salar del Diablo | 24°37.8667'S; 67°15.7667'W | Barboza G.E. et al. 4349 | 46576.0 | 580.0 | 437.4 | 29375.0 | 8.0 | 290.0 | 47.2 | 11.2 |
Total average | 23586.6 | 696.1 | 816.6 | 17310.8 | 8.4 | 191.1 | 55.0 | 22.9 | ||
Standard deviation (SD) | 18516.6 | 690.5 | 1082.3 | 8977.8 | 0.7 | 76.8 | 20.9 | 11.0 |
Bolivia. Potosí: Dept. Daniel Campos, Uyuni, entrando a Coqueza por el propio salar de Uyuni; 9°54.2333'S; 67°37.3667'W; 3665 m elev.; 13 Dec. 2017; G.E. Barboza 4868 (CORD00086059; LPB).
R.A.
The sheet SGO 055683 bears two labels with different localities, collectors and dates. One label reads “Lycium humile Ph., incolis Jume, Ad aquas [Profetas] deserti frequens, Decembri. Januario, Ph.”, it agrees with the protologue. The other label reads “Lycium humile Ph., Juntas arriba, januar 1885, F. Ph.”, which belongs to a collection done by F. Philippi after the description of the species (1860) and is therefore not original material. All material mounted on this single herbarium sheet belongs to L. humile and it is impossible to recognize the branches which were gathered by R.A. Philippi. In fact, the sheet also has a label written by Muñoz Pizarro indicating that there is a mix (‘mezcla!’), which likely refers to mixed material.
After the work of Muñoz Pizarro,
Lycium humile is easily identified by the prostrate or even mat-forming growth habit and very succulent leaves, and during summer, by the numerous white flowers and blackish berries, which also grow almost on the soil surface. In addition, aerial organs represent a smaller part of the total plant architecture than the very well-developed subterranean organs which may help to reduce water loss (
Lycium is the Solanaceae genus with the highest number of reported taxa growing in saline environments on a global scale (
Further botanical explorations are encouraged to increase the collection in Bolivia and also, to verify if the species grows in the region of Tarapacá, which would represent its northern limit of distribution in Chile. This is because the only specimens related to this area are probably duplicates (K000586026 and CORD00021076) and were labelled without a precise locality. The label of the specimen at K reads “Lycium humile Ph. Chili, Com. R.A. Philippi 2/1888. Tarapacá”, while the label of the specimen at CORD states “Lycium humile Phil. Chile. Prov. Tarapacá: Tarapacá. Leg. R.A. Philippi”. These collections were probably collected by F. Philippi and C. Rahmer, during the expedition to the province of Tarapacá in 1885 and distributed (communicated) by R.A. Philippi in 1888. Several specimens from this trip were distributed to foreign herbaria, only with the name of the species and “Tarapacá”, despite the trip covering the High Andes from Copiapó to Pica, going through Antofagasta de la Sierra (Argentina). As there are no other specimens from Tarapacá region, the presence of the species in this region is doubtful. A similar situation occurs in Jujuy province (Argentina), where the only specimen was collected 50 years ago and, despite our expeditions, we have not found the species in the surrounding area of the specimen collection site or in other saline environments of this province such as Salinas Grandes and Salar de Olaroz.
In the studied sites, L. humile was one of the dominant species, reaching covers higher than 35% in sites with high bare soil (> 50%). This evidences its essential role as primary producer in this extreme ecosystem since L. humile contributes greatly to the composition and structure of vegetation in saline environments of the Altiplano-Puna region. In fact, L. humile is the characteristic species of an association and alliance described in Chile (
Halophytes represent fewer than 2% of the Angiosperms (
We thank Alicia Marticorena, Amalia A. Suárez, Eva García Ibáñez, Gabriel Bernardello, James C. Solomon, Michael Dillon, Nicolás García Berguecio, Roberto Güller, Stephan Beck, and Víctor Ardiles for providing information or digital images of specimens. We thank the reviewers and editor for helpful comments. We are very grateful to Javier Palchetti for his assistance in preparing the English version of the manuscript. MVP thanks Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) for a doctoral fellowship. This work was supported by Secretaría de Ciencia y Tecnología UNC (Res. 411–18), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) Argentina (PIP number 11220170100147CO) and Fondo Nacional de Desarrollo Científico y Tecnológico (Fondecyt Nº 1180211) from Agencia Nacional de Investigación y Desarrollo (ANID), Chile.
Occurences of Lycium humile in South America
Data type: occurences
Explanation note: Living in extreme environments: distribution of Lycium humile (Solanaceae), an endemic halophyte of the Altiplano-Puna region, South America.