Lycium humile Phil., Fl. Atacam. 43. 1860.

Palchetti, Maria Virginia, Cantero, Juan Jose, Morales-Fierro, Vanezza, Barboza, Gloria E. & Moreira-Munoz, Andres, 2021, Living in extreme environments: distribution of Lycium humile (Solanaceae), an endemic halophyte from the Altiplano-Puna region, South America, PhytoKeys 185, pp. 1-15 : 1

Lycium humile Phil., Fl. Atacam. 43. 1860.

Fig. 1

Type.

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 Muñoz Pizarro 1960, pg. 116: SGO! [SGO000004448, acc. # 055683; Fig. 2 ], isolectotype: W n.v. [cited as isosyntype by Bernardello (1986)].

Description.

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.

Phenology.

Flowering late September-March; fruiting late December-April.

Vernacular names and uses.

Bálsamo finito, ch’ampita ( Villagrán and Castro 2003); jume ( Philippi 2008; Medina 2012); sacha uva or sachauva ( Villagrán and Castro 2003; Bernardello 2013); tomatillo ( Villagrán and Castro 2003; Medina 2012); uvilla ( Villagrán and Castro 2003); walcha ( Aldunate et al. 1981; Villagrán and Castro 2003); waycha ( Villagrán and Castro 2003; Medina 2012), wicha ( Villagrán and Castro 2003; Medina 2012; Gamboa Fuentes 2014). This species has been reported as fodder ( Aldunate et al. 1981; Villagrán and Castro 2003; Gamboa Fuentes 2014) and probably has medicinal uses associated with rituals to remove evils ( Villagrán and Castro 2003; Medina 2012). Fruits have been reported as edible ( Philippi 2008) and may have tinctorial properties ( Bernardello 1986; Villagrán and Castro 2003; Medina 2012; Gamboa Fuentes 2014).

Distribution.

Lycium humile is distributed in the Andean region, southern South America (Argentina, Bolivia and Chile), at 2300-4100 m elevation (Fig. 3 ). In northwestern Argentina, it inhabits sites at 3000-4000 m elev. in the provinces of Catamarca (Antofagasta de la Sierra and Belén departments) and Salta (Los Andes department), and there is also a specimen collected in Jujuy province, Tumbaya department (Ancibor and Ruthsatz 65; BAA). In northeastern Chile, it occurs throughout the species’ elevation range, in the regions of Antofagasta (Antofagasta and El Loa provinces) and Atacama ( Copiapó and Chañaral provinces). In southwestern Bolivia, it grows in Potosí department, at the edges of Salar de Uyuni at ca. 3600 m elev. Previous publications ( Bernardello 1986; Rodriguez et al. 2018; Zuloaga et al. 2019) have cited the species in the Chilean region of Tarapacá, however after studying herbarium material from Chile we consider its presence on this administrative region as doubtful (see discussion).

Habitat and ecology.

The species preferentially grows in saline clay soils, and less frequently in sandy soils. It is commonly found in saline mudflats of salars (Fig. 4 ). In the analyzed sites of the Altiplano-Puna region where L. humile grows, soils showed very high salinity reaching high EC (~300 dS/m) and Na+ (~30 g/L) values, and low vegetation cover, with an average bare soil of 55 (SD 20.9) %. Lycium humile showed an average cover percentage of 22.9 (SD 11) % with a maximum value of ~40% in Salar de Antofalla (Catamarca, Argentina, Table 1 ). The species occurs in plant communities with low species richness, along with Amaranthaceae , Nitrophila australis Chodat & Wilczek and Salicornia pulvinata R.E.Fr.; Asteraceae , Baccharis acaulis (Wedd. ex R.E.Fr.) Cabrera; Frankeniaceae , Frankenia triandra ; Juncaginaceae , Triglochin concinna Burtt Davy; and Poaceae , Distichlis humilis and D. spicata .

Conservation status.

According to the IUCN criteria ( IUCN 2019), a category of Least Concern (LC; B, C and D criteria) is recommended for Lycium humile , based on its extent of occurrence of 190,477 km2, area of occupancy of more than 2,000 km2, and large population size with more than 10,000 mature individuals observed. Large mining operations in the Andes may produce a continuing decline of area, extent and/or quality of habitat ( Schiaffini 2013; Liu et al. 2019) which could adversely affect some subpopulations located at specific sites of the salars. But considering its widespread occurrence and healthy populations found in several locations within protected areas in Argentina (Laguna Blanca Biosphere Reserve, Lagunas Altoandinas y Puneñas de Catamarca Ramsar Site and Los Andes Provincial Reserve) and Chile (Llullaillaco National Park), this activity may not represent a current threat to this species at regional scale.

New country record.

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).

Taxonomic note.

R.A. Philippi (1860) described L. humile based on his plant collections from his trip to the Atacama Desert during the summer of 1853-1854. The protologue mentioned three localities in Antofagasta, Chile: "primum prope Cachiyuyal 25°22' lat. m. 4000 p.s.m. legi, deinde ad aquam Profetas dictam 24°45' lat. m., 9000 p.s.m., in valle Chaco 25°15' lat. m., 8500 p.s.m.". Of these three syntypes, Muñoz Pizarro (1960) found a single sheet at SGO (acc. # 055683; Fig. 2 ) that matches the species and the protologue, being designated by him as “type” of L. humile . We consider his citation as an inadvertent lectotypification (see article 7.11 in Turland et al. 2018).

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, Bernardello (2013) selected as the lectotype of L. humile the specimen SGO 055684, whose label reads "Encantada, Chaco". Although the second locality “Chaco” is mentioned in the protologue, this specimen cannot be considered as lectotype because it was collected by K. Reiche (inferred by the handwriting of the collector; Muñoz-Schick et al. 2012) after the publication of the protologue and therefore it is not original material (see article 9.4 in Turland et al. 2018).

Figures

Figure 1. Lycium humile A overview of a plant in its habitat B flower C fruits D plant architecture.

Figure 2. Lectotype of Lycium humile Phil. (SGO 055683). Digital image by courtesy of the Museo Nacional de Historia Natural.

Figure 3. Distribution map of Lycium humile (light-blue circles) in the Altiplano-Puna region.

Figure 4. Saline environments of the Altiplano-Puna region (South America) in which Lycium humile grows A Salar del Hombre Muerto (Catamarca, Argentina) B Los Colorados (Salta, Argentina) C Salar de Uyuni (Potosi, Bolivia).