Capsicum cornutum (Hiern) Hunz., Huitieme Congr. Int. Bot. Paris. Comptes Rend. Seances Rapp. & Commun. 1954, sect.4: 73. 1956.

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

13. Capsicum cornutum (Hiern) Hunz., Huitieme Congr. Int. Bot. Paris. Comptes Rend. Seances Rapp. & Commun. 1954, sect.4: 73. 1956.

Figs 52 , 53

Bassovia cornuta Hiern, Vidensk. Meddel. Naturhist. Foren. Kjøbenhavn: 59. 1877. Type. Brazil. Rio de Janeiro: Rio de Janeiro, [no date], A.A.W. Lund s.n. (lectotype, designated here: C [C10019145]; isolectotypes: [K000585893], P [P00410056]).

Capsicum dusenii Bitter, Abh. Naturwiss. Vereine Bremen 24: 520. 1919. Type. Brazil. São Paulo: Serra do Mar, Alto da Serra, 30 Sep 1912, P.K.H. Dusén 14227 (lectotype, designated here: S [acc. # S04-2813]; isolectotypes: CORD [CORD00006948 fragment ex S], RB [RB01413389], S [acc. # S18-42558]).

Type.

Based on Bassovia cornuta Hiern.

Description.

Erect shrubs or subshrubs, (0.80-) 1-3.5 m tall, with the main stem thick, ca. 2.5 cm in diameter at base, much branched above, the branches dichotomously spreading in a typical “zig-zag” appearance. Young stems angled, fragile, green or brown, densely pubescent, with spreading, more or less rigid, brilliant and ferruginous, simple, uniseriate, (3-) 5-9-celled, eglandular trichomes 0.5-3 mm long, rarely glabrescent; nodes solid, green; bark of older stems dark brown, sparsely pubescent; lenticels absent. Sympodial units difoliate, the leaves geminate; leaf pair unequal in size, similar in shape. Leaves membranous, slightly discolorous, green above, light green beneath, densely pubescent adaxially with appressed-antrorse eglandular trichomes similar to those of the stems and abundant spreading, uniseriate, 5-8-celled, eglandular trichomes abaxially, especially on the veins and margins; blades of major leaves 6-16 (-18) cm long, 4-8 cm wide, ovate or widely elliptic, the major veins 6-8 on each side of mid-vein, the base attenuate, the margins entire, the apex acuminate; petioles 0.3-0.5 (-0.8) cm long, densely pubescent with spreading eglandular trichomes; blades of minor leaves (3-) 4-6 cm long, 1.5-3.2 cm wide, elliptic or ovate, the major veins 3-5 on each side of mid-vein, the base attenuate, the margins entire, the apex acute; petioles 0.2-0.4 cm long, same pubescence as the major leaves. Inflorescences axillary, 2-5 (-7) flowers per axil or flowers solitary; flowering pedicels (22-) 25-35 mm long, delicate, angled, erect, geniculate at anthesis, green or green with purple lines, moderately pubescent, the eglandular trichomes long, spreading; pedicels scars inconspicuous. Buds ovoid, inflated, white with green and purple spots. Flowers 5-merous. Calyx 1-2 mm long, 4-5 mm wide, cup-shaped, thin, green, densely pubescent with spreading eglandular trichomes, the calyx appendages (5-) 7-10 unequal, the five main appendages 2.5-5 (-6), the five secondary appendages shorter 0.5-1.5 (-2) mm long, thin, erect or spreading, linear or subulate, inserted very close to the margin. Corolla (8-) 9-14 mm long, 18-22 mm in diameter, white with purple and yellowish-green spots outside, white with intense small purple or reddish-brown spots amongst the veins and in the throat and yellowish-cream centre within, stellate with thin interpetalar membrane, lobed halfway or less of the way to the base, the tube 4-5 mm long, pubescent adaxially with a continuous ring of glandular trichomes (stalk long, 2-3-celled; head globose, peltate, unicellular), glabrous abaxially, the lobes 3.5-6.8 mm long, 3-5.5 mm wide, broadly triangular, spreading, glabrous adaxially and with eglandular trichomes 3-6-celled on the veins abaxially, the margins papillate, the tips acute, cucullate, papillate. Stamens five, equal; filaments 1.4-2.2 (-2.5) mm long, white or cream, inserted on the corolla ca. 1.75 mm from the base, with auricles fused to the corolla at the point of insertion; anthers 1.2-2.3 mm long, ellipsoid, pale grey or grey, not connivent at anthesis. Gynoecium with ovary ca. 2 mm in diameter, light green, globose; ovules more than two per locule; nectary ca. 0.3 mm tall; styles homomorphic, 4-6.8 mm long, exserted ca. 1.3 mm beyond the anthers, white or cream, clavate; stigma 0.3 mm long, 0.6-0.8 mm wide, globose or discoid, pale green. Berry 7-10 mm in diameter, globose, green when immature, greenish-golden yellow at maturity, deciduous, slightly pungent, the pericarp thin, translucent, with giant cells (endocarp alveolate); stone cells absent; fruiting pedicels (25-) 30-38 mm long, pendent and curved, angled, widened distally, green; the fruiting calyx 4-5 mm in diameter, persistent, not accrescent, discoid, green, the appendages 1-6 mm long, spreading. Seeds (4-) 6-18 (-20) per fruit, 3-3.5 mm long, 2.5-3.5 mm wide, teardrop-shaped, black, the seed coat reticulate and tuberculate at margins (SM), reticulate with pillar-like outgrowths at margins (SEM), the cells polygonal in shape, the lateral lateral walls straight; embryo imbricate.

Distribution.

Capsicum cornutum is endemic to south-eastern Brazil, confined to small areas in São Paulo and Rio de Janeiro States (Fig. 51 ).

Ecology.

Capsicum cornutum occurs in the Atlantic Forest (Mata Atlântica), in the Dense Ombrophilous Forest (Floresta Ombrófila Densa), in semi-shade, on the edge of steep, open ravines or along forest roadsides, between 500 and 900 m elevation.

Phenology.

Flowering from September to May. Fruiting from December to May and June.

Chromosome number.

n = 13 ( Pozzobon and Schifino-Wittmann 2006); 2 n = 2x = 26 (Pozzobon et al. 2016).

Common name.

Brazil. Pimentinha-do-mato (Rio de Janeiro, Bovini & Giordano 363).

Uses.

None recorded.

Preliminary conservation assessment.

EOO (17,682.480 km2); AOO (72 km2). Capsicum cornutum occurs exclusively in the Brazilian Atlantic Forest, one of the world’s biological diversity hotspots that is increasingly threatened by the rapid destruction (deforestation) and fragmentation of its natural areas. This species inhabits the Serra do Mar, in much reduced subpopulations mainly in officially protected areas, such as Parque Nacional do Itatiaia and APA-Cairuçu (Rio de Janeiro), Parque Estadual da Serra do Mar and Reserva Biológica do Alto da Serra de Paranapiacaba ( São Paulo). Based on the EOO, the continuing decline observed in the quality of its habitat outside of the natural reserves and decline in number of locations, we assign the threat status of Vulnerable (VU; B1ab(iii,iv)).

Discussion.

Capsicum cornutum is a member of the Atlantic Forest clade ( Carrizo García et al. 2016). It is rarely collected, but easily recognised by its dense pubescence, usually 7-10 unequal calyx appendages and white, stellate corollas with purple and yellowish-green spots abaxially and intense small purple or brownish-red spots adaxially (Table 4 ). Some specimens from the State of Rio de Janeiro (Paraty) lack the typical dense pubescence.

Capsicum villosum is superficially similar to C. cornutum in its pubescence, geniculate pedicels and corolla and fruit colour, but differs in having five subequal calyx appendages, a smaller corolla (7-9 mm long, 14-14.5 mm in diameter vs. 8-14 mm long, 18-22 mm in diameter in C. cornutum ), a different design of purple pigmentation in the corolla lobes and throat (two large spots at the base of each lobe forming a more or less ring-like purple centre within the corolla vs. many small purple or reddish-brown spots amongst the veins in C. cornutum ) and filaments 1.6-2.4 longer than the anthers (vs. filaments somewhat longer than the anthers in C. cornutum ).

Capsicum cornutum has also been confused in herbaria with another species of the Atlantic Forest clade, C. recurvatum . Capsicum cornutum differs in having dense pubescence of long spreading trichomes, longer and erect or spreading calyx appendages and purple pigmentation within the corolla; C. recurvatum is much less pubescent with shorter antrorse trichomes, has shorter and recurved calyx appendages and has a corolla with greenish-yellow spots within and no purple pigmentation. Capsicum cornutum is sympatric, but cannot be confused, with C. schottianum . The presence of calyx appendages, long trichomes and a larger corolla distinguish C. cornutum from C. schottianum .

Carrizo García et al. (2013) mentioned a population named Capsicum ‘cunha’ (from the area around Cunha in São Paulo, Brazil, no voucher cited) with entirely white corollas and with a combination of traits matching both C. recurvatum (calyx morphology) and C. cornutum (pubescence pattern). It is probable that Capsicum ‘cunha’ belongs to C. recurvatum , in light of the fact that they share the characters of the calyx (which are very consistent in C. recurvatum ) and they lack pigmentation in the corolla (which occurs also in C. recurvatum ). Capsicum cornutum is distinctive in the density, orientation and length of the trichomes, so it will be important to ascertian if those characters are also present in Capsicum ‘cunha’ or if these plants are more similar to C. recurvatum . Geographically, C. recurvatum has also been collected in the same locality of Capsicum ‘cunha’.

Hiern (1877) described C. cornutum under Bassovia (now a synonym of Solanum , cfr. Solanaceae Source, www.solanaceasource.org), but he clearly stated in the protologue "calyce parvulo cupulari truncato dentibus accesoriis 10 subulatis... antheris … lateraliter dehiscentibus ..." both unequivocal characters for Capsicum ( Hunziker 2001). Bitter (1921: 333) doubted its position in Capsicum sect. Decameris , a section he established to place Capsicum species with 10-toothed calyces ( Bitter 1919: 293).

When describing B. cornuta , Hiern (1877) did not cite specific herbarium in the protologue; we designate lectotype the best-preserved of Lund’s collections held at Copenhaven.

In his description of C. dusenii , Bitter (1919) described a calyx with 10 linear, unequal appendages and a white corolla with numerous violet maculations, these features being the same diagnostic traits used by Hiern (1877) for B. cornuta . He also cited Dusén 8255 (State of Paraná, Brazil) as belonging to C. dusenii , but this specimen corresponds to Athenaea wettsteiniana (Witasek) I.M.C.Rodrigues & Stehmann ( Hunziker and Barboza 1990, as Aureliana wettsteiniana (Witasek) Hunz. & Barboza). In describing C. dusenii , Bitter (1919) indicated that he had seen the collection Dusén 14227, but also that Dusén’s notes stated that his collections 599a, 6559 and 8255 also corresponded to the same taxon; Bitter cited no herbaria in the protologue. We have found duplicates of Dusén 14227 at S and RB. In S, the collection is mounted on two sheets. All of them are very good flowering branches. We designate S04-2813 that is annotated by Bitter as the lectotype for this name.

Specimens examined.

See Suppl. material 4: Appendix 4.

Figures

Figure 51. Distribution of C. coccineum and C. cornutum.

Figure 52. Capsicum cornutum A leaf B eglandular trichomes of the leaf C flowering branch D sector of opened corolla E gynoecium F fruit G fruit (one carpel), in longitudinal section H anatomical detail of the pericarp (note the giant cell in the mesocarp) I seed J seed, in cross section K structure of seed coat at the seed margin L embryo A-G from Hunziker 19557 H-L from Kuhlmann 4321. Drawn by L. Sanchez. Modified from Hunziker (1971), reproduced with permission.

Figure 53. Capsicum cornutum A plant B flower on geniculate pedicel C flower, in lateral view, showing the calyx D flower, in front view E immature fruit. From Barboza & Cosa 2525. Photos by G. E. Barboza.