Capsicum chacoense Hunz., Darwiniana 9(2): 228. 1950.

Barboza, Gloria E., Garcia, Carolina Carrizo, Bianchetti, Luciano de Bem, Romero, Maria V. & Scaldaferro, Marisel, 2022, Monograph of wild and cultivated chili peppers (Capsicum L., Solanaceae), PhytoKeys 200, pp. 1-423 : 1

10. Capsicum chacoense Hunz., Darwiniana 9(2): 228. 1950.

Figs 45 , 46

Capsicum chacoense Hunz. var. tomentosum Hunz., Darwiniana 9(2): 235. 1950. Type. Argentina. Chaco: [Dept. Independencia], Colonia J.J. Mármol, 31 Dec 1946, F. Buratovich 117 (holotype: LIL [acc. # 173409); isotype: B [B10-1067916]).

Type.

Argentina. Chaco: [ Dept. Primero de Mayo ] entre Colonia Benítez y Resistencia, 12 Mar 1945, A.T. Hunziker 7340 (lectotype, designated here: CORD [CORD00003920]; isolectotypes: CORD [CORD00003919, CORD00087962]) .

Description.

Low compact shrubs or subshrubs 0.40-1 (-2.5) m tall, much branched from a thick basal rootstock, with the main stem 2-3 cm in diameter at base, the branches expanded and divaricated, in a typical “zig-zag” appearance. Young stems strongly 3-4-angled, fragile, green or purple, sparsely to densely pubescent with antrorse and more or less rigid or spreading and flexuous, simple, uniseriate, 3-7-celled, eglandular trichomes 0.03-0.8 (-1.4) mm long, rarely branched trichomes 1-7 mm long; nodes green; bark of older stems brown, glabrescent to glabrous; lenticels sparse. Sympodial units unifoliate or difoliate, the leaves geminate; leaf pair more or less similar in shape and size. Leaves membranous, slightly discolorous or concolorous, glabrescent to densely pubescent with eglandular trichomes similar to the stems on both surfaces and margins; blades of all leaves 2-6 (-8) cm long, 1-3.5 (-5) cm wide, ovate, narrowly ovate or rarely elliptic, the major veins 3-4 on each side of midvein, the base attenuate and asymmetric, the margins entire, the apex long-acuminate; petioles 0.5-2 (-3.5) cm long, glabrescent to densely pubescent. Inflorescences axillary, flower solitary; flowering pedicels (5-) 10-25 (-40) mm long, strongly angled, erect, geniculate at anthesis, green, scarcely to moderately pubescent; pedicels scars inconspicuous. Buds globose or ovoid, white. Flowers 5-merous. Calyx 1.2-2 mm long, 2-2.5 mm wide, cup-shaped, thick, green, moderately pubescent with the same eglandular trichomes as stems, the calyx appendages 7-10 (rarely 5), unequal, rarely subequal, the five main appendages longer, 0.5-1.5 mm long, 0.3 mm wide, alternating with 2-5 shorter secondary appendages up to 0.7 mm long, thick, erect or slightly spreading, cylindrical or slightly compressed, inserted close to the margin, sparsely pubescent with the same trichomes as calyx tube. Corolla 4-6 (-9) mm long, 9-11 mm in diameter, thick, entirely white, stellate with interpetalar membrane, lobed 1/2 or less of the way to the base, glabrous adaxially and abaxially, the tube 2-4 mm long, the lobes 2-2.6 (-3.1) mm long, 2-2.4 mm wide, triangular, spreading, the margins papillate, the tips acute, papillate. Stamens five, equal; filaments 0.8-1.5 mm long, white, inserted on the corolla 1-1.3 mm from the base, with conspicuous auricles free, not fused to the corolla at the point of insertion; anthers (0.9-) 1.2-1.5 mm long, ellipsoid, yellow or cream, not connivent at anthesis. Gynoecium with ovary 1.5-2.3 mm long, ca. 1.7 mm in diameter, light green, ovoid; ovules more than two per locule; nectary ca. 0.4 mm tall, light green; styles homomorphic, 2.4-2.8 (-4) mm long, exserted ca. 1-1.5 mm beyond the anthers, white, cylindrical; stigma ca. 0.2 mm long, 0.2 mm wide, cream or light green, globose. Berry 7-10 mm in diameter, globose or (6-) 8-14 mm long, 5-8 mm in diameter, ellipsoid, green or green with blackish spots when immature, orange to bright red at maturity, deciduous, pungent, in some populations, non-pungent, the pericarp thick, opaque, with giant cells (endocarp alveolate); stone cells absent; fruiting pedicels 15-20 mm long, erect, strongly angled, widened distally, green; fruiting calyx 4-5 mm in diameter, persistent, not accrescent, discoid, green, the appendages 0.5-1.6 mm long, spreading or slightly recurved. Seeds 14-25 per fruit, 3.4-4 mm long, 2.8-3 mm wide, C-shaped, rarely subglobose or reniform, pale yellow, the seed coat smooth to reticulate (SM), reticulate-cerebelloid (SEM), the cells irregular in shape, the lateral walls strongly sinuate in seed body, nearly straight at margin; embryo imbricate or coiled.

Distribution.

Capsicum chacoense is a widespread species usually confined to Chaco vegetation, which extends from Bolivia and Paraguay to central Argentina (Fig. 41 ).

Ecology.

Capsicum chacoense is a typical component of the dry and subhumid Gran Chaco forests ranging from the inter-Andean valleys at higher elevations to the lower Chaco forests in northern Argentina and Paraguay. Capsicum chacoense is found in the undergrowth, beneath the shade of nurse shrubs or trees, from 50-2,700 m elevation.

Phenology.

Flowering from late October to March and April, fruiting from January to May or June.

Chromosome number.

n = 12 ( Moscone 1992); 2n = 24 ( Pickersgill 1977; Moscone 1990; Moscone et al. 1993, 1995, 2007).

Common names.

Argentina: Ají (Catamarca, Brizuela 1127; Chaco, Aguilar 568; Córdoba, Fernández 17; Corrientes, Nicora s.n.; Santiago del Estero, Soriano & Barret 3592), Bolita (Santiago del Estero, Perrone s.n.), Cumbaré ( Córdoba, Castellanos 217), Cumbarí (Catamarca, de Ance 81; Corrientes, Ibarrola 2988; La Rioja, Hunziker 4807), Lají ( Córdoba, Lorentz s.n.), Pipí (Formosa, Morel 910), Putaparió (Chaco, Gaillard s.n.; Córdoba, Cocucci 4966; Tucumán, Schreiter 1927), Putaqueteparió ( Córdoba, Hawkes et al. 3308), Uchuca (Catamarca, Vervoorst 3535), Ají cumbarí (Catamarca, Schickendantz 74; Chaco, Schulz 2; Córdoba, Castagnino s.n.; La Rioja, Giacomelli 130), Ají chuca (Chaco, de Ance 81), Ají fuerte ( Córdoba, Villafañe 400), Ají picante ( Córdoba, Botta 115), Ají quitucho (Catamarca, Capparelli 158), Ají uchiquita (La Rioja, Hunziker 4807), Ají uchuco (Catamarca, Falcone & Castellanos 262), Ají del campo (Chaco, Schulz 92; Córdoba, Castellanos 217; La Rioja, Hunziker 5088; San Luis, Anderson 1447; Santa Fe, Krapovickas 762), Ají del monte (Catamarca, Cabrera 1132; Chaco, Fortunato 1445; Córdoba, Spegazzini s.n.; Salta, Ayarde & Sidán 299; Santiago del Estero, Bartlett 20435; Tucumán, Schreiter 1927), Ají mala palabra (Santiago del Estero, Crespo s.n.), Ají puta parió (San Juan, Cortez 156), Ají quitucho dulce (Salta, Hunziker 1578), Picante del monte (Jujuy, Joergensen s.n.), Pimiento del monte (Chaco, Meyer 8561); Bolivia: Aribibi (Santa Cruz, Navarro & Vargas C. 261), Ají del zorro (Chuquisaca, Saravia Toledo 10343); Paraguay: Ají ( Boquerón, August 18), Cambarí (Central, Rojas 10821), Cumbary (Capital, Rojas 14325).

Indigenous names.

Argentina: Atéshuk (Chorote, Scarpa 2007), Awarañink¨i’¨i’ ( Tapieté, Montani and Scarpa 2016), Chemmak’-raík’ (= picante) ( Mocoví, Scarpa and Rosso 2014), Ke-ig ( Guaraní, Corrientes, Ibarrola 2988), Kodae ( Pilagá, Formosa, Martínez Crovetto 31, Arenas 3043), Ko’rae ( Pilagá, Filipov 1994), Ko’rai’ ( Pilagá, Formosa, Arenas 1956), Pájanak (Chorote, Scarpa 2007), Pa: nãn (Salta, Arenas 2121), Quihiy (Chaco, Escobar 19); Bolivia: Aguara keu (Santa Cruz, Bourdy 2000), Kî mi’ (Santa Cruz, de Michel 2568); Paraguay: Atés ( Boquerón, Arenas 1688), Atic (Presidente Hayes, Arenas 1546), Ciaq taqatic (Presidente Hayes, Arenas 2377), Hũpita ( Boquerón, Arenas 1853), Naatikgit ( Boquerón, Arenas 436), Yemade (Toba, Presidente Hayes, Williams et al. 140).

Uses.

The pungent fruits are locally used as spicy food additives for both local and indigenous people ( National Research Council 1989; Arenas and Scarpa 2007; Biurrun et al. 2007; Scarpa 2007; Martínez Crovetto 2014; Montani and Scarpa 2016; Saur Palmieri et al. 2018). In regional markets, fruits are sold fresh or as pickles in oil or vinegar (Barboza, pers. obs.). Fruits are also used in traditional medicine (see Table 3 ).

Preliminary conservation assessment.

EOO (1,724,002 km2); AOO (952 km2). Capsicum chacoense is widespread across subtropical Chaco forests from Bolivia to Paraguay and is assigned the Least Concern (LC) category.

Discussion.

Capsicum chacoense belongs to the Baccatum clade ( Carrizo García et al. 2016). It has a peculiar dwarf habit, profusely branched from the thick rootstock with small leaves, solitary flowers, entirely white corollas, filaments with conspicuous free auricles at point of insertion to the corolla and abundant red mature fruits per plant. Its most variable character is pubescence. Typically, plants are sparsely pubescent, but densely tomentose populations grow in north-eastern Argentina (Chaco) and Paraguay (Alto Paraguay), which, in the past, were recognised as a separate variety, C. chacoense var. tomentosum ( Hunziker 1950). Some of these tomentose populations were included in Hunziker’s circumscription of C. microcarpum var. tomentosum (= C. rabenii ) ( Hunziker 1950), leading to confusion between the two taxa.

A second variable feature is the number and degree of development of the calyx appendages. The most common condition is the presence of calyces with 10 unequal appendages, the five main ones longer and alternating with five shorter, all of them usually well-developed (that is, appendages exceed the truncate calyx edge). In some cases, the shorter appendages vary from 2-5, with some exceeding the calyx edge and others scarcely noticeable, reduced to a mucro. Calyces with this second pattern create confusion in the identification of fruiting specimens, especially when all short appendages are not well-developed. Often, these specimens are annotated in herbaria as C. baccatum from which C. chacoense can be distinguished by its smaller and entirely white corollas.

The fruits of C. chacoense are locally very appreciated for their flavour and high pungency (see references in Uses). However, C. chacoense is naturally polymorphic for the production of capsaicinoids, such that completely pungent and completely non-pungent individuals co-occur in some Bolivian populations (Tewskbury et al. 2006); non-pungent fruits have also been recorded in Argentinean populations (e.g. Salta, Hunziker 1578). Tewksbury et al. (2008b) demonstrated that the pungency variation found in C. chacoense may be an adaptive response to selection by a microbial pathogen. Thus, capsaicinoids protect the fruits and seeds from fungal pathogens ( Fusarium ) that severely reduce seed viability.

There is little information about which birds, the most effective dispersers of Capsicum seeds, eat C. chacoense fruits. Information from a herbarium label (Bolivia, Debouck 3016) suggests that small parrots eat the fruits of this species. Tewskbury et al. (2006) mentioned Elaenia parvirostris ‘fiofío pico corto’ (Fam. Tyrannidae ) and Turdus amaurochalinus 'zorzal chalchalero’ (Fam. Turdidae ) as the major dispersers of Capsicum seeds in Bolivia.

In the protologue of C. chacoense , Hunziker (1950) indicated "Typus speciei. (ATH)" [Armando Teodoro Hunziker] referring to his own Herbarium now housed at CORD. In CORD, there are three mounted sheets of Hunziker 7340, two of them (sheets A and B) are labelled as “holotype” (barcodes CORD00003919, CORD00003920) and the third one (CORD00087962) has a label in Hunziker’s hand, indicating it is a duplicate specimen (probably with the intention to be donated elsewhere, but now mounted and accessioned at CORD). Sheet B contains a complete fruiting young individual with a label where the word Typus was handwritten by Hunziker as an indication that it should be the holotype; we are designating this sheet B (CORD00003920) as the lectotype.

Specimens examined.

See Suppl. material 4: Appendix 4.

Figures

Figure 41. Distribution of C. carassense, C. ceratocalyx and C. chacoense

Figure 45. Capsicum chacoense A root B fruiting branch C eglandular trichome of the leaf D flower E sector of opened corolla F gynoecium G fruit H seed I seed, in cross section J embryo A, C-F from Hunziker 18572 B, G-J from Hunziker et al. 25388. Drawn by N. de Flury. Published in Barboza (2013), courtesy of the Board of the Instituto Darwinion (San Isidro, Buenos Aires, Argentina), reproduced with permission.

Figure 46. Capsicum chacoense A plant B flower bud C flower, in pre-anthesis D flower, in front view E immature fruit F mature fruit A-F from Barboza et al. 4910. Photos by G. E. Barboza.