Capsicum rhomboideum (Dunal) Kuntze, Revis. Gen. Pl. 2: 450. 1891.

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

40. Capsicum rhomboideum (Dunal) Kuntze, Revis. Gen. Pl. 2: 450. 1891.

Figs 112 , 113

Witheringia rhomboidea Dunal, Solan. Syn. 1. 1816. Type. Colombia. Quindio: "Mont Quindiu", F.W.H.A. von Humboldt & A. Bonpland s.n. (holotype: P-Bonpl. [P00670657]).

Witheringia dumetorum Dunal, Solan. Syn. 1. 1816. Type. Ecuador. Pasto: Pasto, F.W.H.A. von Humboldt & A. Bonpland s.n. (holotype: P-Bonpl. [P00670658]).

Witheringia ciliata Kunth, Nov. Gen. Sp. [H.B.K.] (quarto ed.) 3: 11. 1818. Type. Ecuador. Pasto: " Crescit in Andibus frigidis Pastoensium prope Tulcan, alt. 1580 hex." [474 m], F.W.H.A. von Humboldt & A. Bonpland s.n. (holotype: P [not found]; isotype: B destroyed, photo F neg. 2875]).

Witheringia mollis Kunth, Nov. Gen. Sp. [H.B.K.] (quarto ed.) 3: 12. 1818. Type. Peru. Cajamarca: " Crescit in Regno Peruviano prope urbem Caxamarca, alt. 1500 hex" [450 m], F.W.H.A. von Humboldt & A. Bonpland s.n. (lectotype, designated here: P-Bonpl. [P00670656]; isotype: B [destroyed, photo F neg. 2877]).

Capsicum aggregatum Willd. ex Roem. & Schult., Syst. Veg., ed. 15 bis [Roemer & Schultes] 4: 809. 1819. Type. No locality information given "Habitat …”, " Capsicum aggregatum , herb. Willd.)" (holotype: B [B-W04434-01-0]).

Witheringia diversifolia Klotzsch ex Walp., Repert. Bot. Syst. (Walpers) 3: 29. 1844. Type. Cultivated in Berlin Botanical Garden, Germany "In Mexico- (Floruit in horto Berolinensi botanico mense Aprili anni 1841)" (no specimens cited; no original material found).

Brachistus ciliatus (Kunth) Miers, Ann. Mag. Nat. Hist. ser. 2, 3(16): 263. 1849. Type. Based on Witheringia ciliata Kunth.

Brachistus rhomboideus (Dunal) Miers, Ann. Mag. Nat. Hist. ser. 2, 3(16): 264. 1849. Type. Based on Witheringia rhomboidea Dunal.

Brachistus mollis (Kunth) Miers, Ann. Mag. Nat. Hist. ser. 2, 3(16): 264. 1849. Type. Based on Witheringia mollis Kunth.

Brachistus dumetorum (Dunal) Miers, Ann. Mag. Nat. Hist. ser. 2, 3(16): 265. 1849. Type. Based on Witheringia dumetorum Dunal.

Brachistus diversifolius (Klotzsch ex Walp.) Miers, Ann. Mag. Nat. Hist. ser. 2, 3(16): 268. 1849. Type. Based on Witheringia diversifolia Klotzsch ex Walp.

Fregirardia luteiflora Dunal ex Delile, Ind. Sem. Hort. Monsp.: 7. 1849. Type. Cultivated in Montpellier, France. "Hort. Montpellier", 17 Feb 1849, M.F. Dunal s.n. (lectotype, designated by Hunziker 1971, p. 253: MPU, second step designated here: MPU [MPU023032]); isolectotypes: HBG [HBG-511320, G-DC [G00200559], MPU [MPU023031]).

Fregirardia rhomboidea (Dunal) Dunal, Prodr. [A. P. de Candolle] 13(1): 504. 1852. Type. Based on Witheringia rhomboidea Dunal.

Fregirardia dumetorum (Dunal) Dunal, Prodr. [A. P. de Candolle] 13(1): 504. 1852. Type. Based on Witheringia dumetorum Dunal.

Fregirardia mollis (Kunth) Dunal, Prodr. [A. P. de Candolle] 13(1): 505. 1852. Type. Based on Witheringia mollis Kunth.

Fregirardia vargasii Dunal, Prodr. [A. P. de Candolle] 13(1): 505. 1852. Type. Venezuela. Distrito Federal: Circa Caracas, 1830, J.M. Vargas 249 (holotype: G-DC [G00200549; isotype: MPU [MPU023030]).

Solanum mendax Van Heurck & Müll.Arg., Observ. Bot. (Van Heurck): 61. 1870. Type. Ecuador. Tungurahua: Baños, Aug 1857, R. Spruce 5050 (lectotype, designated by Barboza 2011, pg. 29: K [K000201915]; isolectotypes: BM [BM000777290], E [E00202462], G (G0342803, G00342804], GH [GH00077720], K [K000201792, K000201915], MO [MO-1287475, acc. # 1691274, MO-1287476, acc. # 1781034], P [P00410209], W [W-Rchb. 1889-0294613, W-Rchb. 1889-0223014]).

Brachistus pringlei S.Watson, Proc. Amer. Acad. Arts 25: 159. 1890. Type. Mexico. Nuevo León: in the Sierra de la Silla near Monterrey, 28 May 1889, C. G. Pringle 2544 (holotype: GH [00936714]; isotypes: AC [AC00320467], BKL [BKL00004329], BR [BR0000005530854, BR0000005531189], CM [CM1923, acc. # 260433], COLO [00352195], E [E00570143], EAP [EAP71917], F [v0072759F], G [G00342807], GOET [GOET003410], K [K000585889], KFTA [KFTA0002452, KFTA0002453], M [M-0171536], MEL [MEL2442144], MEXU [00028827], MO [MO-022273, acc. # 3727961; MO-153287, acc. # 1768532], NA [NA-0026220], NDG [NDG44985], NY [00138549, 00138550], P [P00410033, P00410034], PH [PH00008049], PUL [PUL00000045], RSA [RSA0006263, acc. # 102428], S [acc. # S-G-1004], UC [UC548235], US [00027409, acc. # 48601], VT [UVMVT026402], W [acc. # 1890-0000820], WU [acc. # 0033958]).

Capsicum ciliatum (Kunth) Kuntze, Revis. Gen. Pl. 2: 450. 1891. Type. Based on Witheringia ciliata Kunth.

Capsicum diversifolium (Klotzsch ex Walp.) Kuntze, Revis. Gen. Pl. 2: 450. 1891. Type. Based on Witheringia diversifolia Klotzsch ex Walp.

Capsicum dumetorum (Dunal) Kuntze, Revis. Gen. Pl. 2: 450. 1891. Type. Based on Witheringia dumetorum Dunal.

Capsicum molle (Kunth) Kuntze, Revis. Gen. Pl. 2: 450. 1891. Type. Based on Witheringia mollis Kunth.

Capsicum vargasii (Dunal) Kuntze, Revis. Gen. Pl. 2: 450.1891. Type. Based on Fregirardia vargasii Dunal.

Capsicum mendax (Van Heurck & Müll.Arg.) J.F.Macbr., Candollea 5: 402. 1934. Type. Based on Solanum mendax Van Heurck & Müll. Arg.

Brachistus haughtii Svenson, Amer. J. Bot. 33: 481, t. 19, f. 2. 1946. Type. Peru. Piura: summit of Cerro Prieto, 4°45'S, 81°15'W, 2500 ft elev., 28/30 Mar 1941, O. Haught & H.K. Svenson 11621 (holotype: BKL [BKL00004328]).

Capsicum pringlei (S.Watson) J.F.Macbr. & Standl., Publ. Field Mus . Nat. Hist., Bot. Ser. 11: 173. 1936. Type. Based on Brachistus pringlei S.Watson.

Brachistus vargasii (Dunal) Pittier, Cat. Fl. Venez. [Pittier] 2: 358. 1947. Type. Based on Fregirardia vargasii Dunal.

Capsicum haughtii (Svenson) J.F.Macbr., Publ. Field Mus . Nat. Hist., Bot. Ser. 13 (V-B, 1): 72. 1962. Type. Based on Brachistus haughtii Svenson.

Type.

Based on Witheringia rhomboidea Dunal.

Description.

Erect, slender and sprawling shrubs or rarely trees (0.5-) 2-3 (-5) m tall, with the main stem 1.8-2.5 cm in diameter at base, profusely branched above, the branches erect or decumbent. Young stems terete or slightly angled, somewhat rigid, glabrous or sparsely to densely pubescent with white or rarely ochraceous, antrorse or spreading, simple, uniseriate, eglandular trichomes 0.3-0.9 mm long or furcate to 3-5-branched (or more) trichomes 0.2-0.8 (-1.5) mm long; nodes green; bark of older stems longitudinally ridged, grey, dark brown or brownish-purple; lenticels abundant, white or light brown. Sympodial units difoliate, the leaves geminate; leaf pair unequal in size and similar or dissimilar in shape. Leaves membranous, discolorous, dark green, slightly glossy above, dull light green, with the primary vein raised beneath, moderately pubescent to glabrous adaxially, moderately to densely pubescent abaxially, with similar antrorse trichomes like those of the stems, sometimes a tuft of trichomes in the vein axils beneath; blades of major leaves (4-) 4.8-12 cm long, 2-5 cm wide, ovate, elliptic or rhomboid-ovate, the major veins 4-6 on each side of mid-vein, the base attenuate or truncate, sometimes asymmetric, the margins entire, the apex acute or obtuse-acuminate; petioles 0.5-1.5 (-1.8) cm, with moderate to dense pubescence of spreading trichomes; blades of minor leaves 2-3 cm long, 1.5-2.5 cm wide, ovate or rhomboid-ovate, the major veins 3-4 on each side of mid-vein, the base short-attenuate, the margins entire, the apex acute or obtuse; petioles 0.3-0.8 cm with similar pubescence as major leaves. Inflorescences axillary, 3-8 (-13)-flowers per axil, rarely solitary; flowering pedicels (8-) 11-28 mm, terete or slightly striate, pendent, non-geniculate at anthesis, green, glabrescent to densely pubescent, the eglandular trichomes short or long, spreading or antrorse; pedicels scars conspicuous, corky. Buds globose, yellow or green. Flowers 5-merous. Calyx 2.7-3.8 mm long, 5-6 mm wide, cup-shaped, green, glabrescent to densely pubescent with antrorse or spreading simple, furcate or dendritic trichomes 0.3-0.8 mm long, the calyx appendages usually five (rare 3-4), 0.9-3 mm long, subequal, erect or spreading, linear-subulate, 0.0-0.3 mm below the margin, with the same pubescence as the calyx tube. Corolla (5-) 6-10 mm long, (8-) 10-12 mm in diameter, yellow, sometimes tinged greenish outside and within, campanulate or campanulate-rotate with a wide interpetalar membrane connecting the lobes up to the distal end, hardly lobed, glabrous adaxially and abaxially, the tube (4.4-) 5.4-9 mm long, the lobes 0.6-1 mm long, 1.6-1.9 mm wide, broadly ovate, the margins finely ciliate, the tips cucullate, papillate. Stamens five, equal; filaments 1.2-2.3 mm long, pale yellow or light green, inserted on the corolla 1-1.3 mm from the base, with auricles fused to the corolla at the point of insertion; anthers (1.4-) 1.6-2.3 mm long, ellipsoid, pale yellow or yellow, not connivent at anthesis. Gynoecium with ovary 1.3-1.6 mm long, 1.2-1.3 mm in diameter, greenish-white, ovoid; ovules more than two per locule; nectary 0.5-0.6 mm tall; styles homomorphic, 3.9-5.8 mm long, barely exserted beyond the anthers, pale yellow, clavate; stigma 0.25-0.5 mm long, 0.4-0.6 mm wide, usually bilobed, light green. Berry 5-9 mm in diameter, globose or globose-depressed, green when immature, bright red turning dark burgundy at maturity, non-pungent, the pericarp thick, opaque, lacking giant cells (endocarp smooth); stone cells absent; fruiting pedicels 15-35 mm long, pendent, terete or angled, widened distally, green; fruiting calyx 4-5 mm in diameter, persistent, not accrescent, discoid, green, the appendages 3-6 mm long, spreading or reflexed. Seeds 24-60 per fruit, 2.4-2.8 mm long, 1.8-2.2 mm wide, C-shaped, reniform, rarely teardrop-shaped, dark brown, rarely light brown, the seed coat reticulate (SM), reticulate-cerebelloid (SEM), the cells irregular in shape, the lateral walls mostly sinuate, wavy at margins; embryo annular or imbricate.

Distribution.

Capsicum rhomboideum is widely distributed from Mexico and Central America to northern Peru (Fig. 114 ).

Ecology.

Capsicum rhomboideum is ecologically adapted to different vegetation formations, but grows mostly in xerophytic thickets and dry forests or in tropical deciduous forests, at 250-2,500 (-3,000) m elevation.

Phenology.

Flowering and fruiting all year.

Chromosome number.

2 n = 2x = 26 ( Pickersgill 1977, as C. ciliatum ; Moscone et al. 2007; Scaldaferro et al. 2013).

Common names.

Colombia: Tinto (Norte de Santander, Garganta 857); Ecuador: Arrayán (Chimborazo, Cerón 15714), Motupe (Imbabura, Vivar C. s.n.), Caspi morocho (Chimborazo, Scolnik 1594), Hierva dura (Carchi, Cerón 11092), Hierba mora (Pichincha, Cerón 6953), 7 varas (Pichincha, Cerón 13171); El Salvador: Mora silvestre (San Miguel, Villacorta et al. 2819), Veranera silvestre ( Ahuachapán, Sandoval 308), Arito de niña ( Ahuachapán, Sandoval 550); Venezuela: Cachimbito (Distrito Federal, Buschel s.n.),

Indigenous name.

Mexico. Tumaltez (Tzeltal, Chiapas, Alonso Méndez 7709).

Uses.

Ecuador. Long stems are used to make drum hoops ( Cerón 13171). Used in medicine (see Table 3).

Preliminary conservation assessment.

EOO (7,747,997.619 km2); AOO (1,964 km2). Capsicum rhomboideum is widespread from Mexico to Peru; we assign the Least Concern (LC) status.

Discussion.

Capsicum rhomboideum belongs to the Andean clade ( Carrizo García et al. 2016). This species is one of the most polymorphic and widespread and has the largest synonymy of all the wild species of Capsicum . Capsicum rhomboideum is distinctive by its habit (shrubs or trees up to 5 m tall), the dark brown or brownish-purple bark with abundant lenticels, inflorescences up to 13-flowered, campanulate or campanulate-rotate yellow corollas, relatively small (5-9 mm in diameter) bright red turning dark burgundy non-pungent fruits, small dark brown seeds (2.4-2.8 mm long) and a mixture of simple and branched pubescence (Fig. 113 ). While the reproductive characters are usually consistent along its wide distribution, the pubescence and leaf shape are the most variable features in C. rhomboideum , this variation being responsible for the many different names given to this species. Some populations are densely pubescent with only simple eglandular trichomes or with both simple and branched trichomes, while others vary from moderately pubescent to glabrescent (a few, completely glabrous). Simple eglandular trichomes range from 3-8 (-11) cells, whereas branched trichomes can be furcate or variously 3-5 (or more)-branched (many branches in different directions). Highly branched trichomes are uncommon in the genus, this character also occurring in a few Brazilian species (e.g. C. longidentatum , C. parviflorum ; Barboza et al. 2011). Leaf shape ranges from ovate, elliptic to rhomboid-ovate and, in some cases, the dissimilarity in size of the leaf pair is not obvious.

Amongst the various names coined by Kunth (1818) under Witheringia (two of them here recognised as synonyms of C. rhomboideum ) is W. ciliata , on which Capsicum ciliatum was based ( Kuntze 1891). Although the name C. ciliatum has been widely used in literature ( Hunziker 1956, 1971; D’Arcy and Eshbaugh 1974; Molina 1975; Nee 1986; Mitchell et al. 1989), C. rhomboideum has priority and is the correct name for this entity ( Hunziker 2001).

We found in the P-Bonpland Herbarium a sheet (P00670656) that seems to be original material of Witheringia mollis and this is selected as the lectotype.

Specimens examined.

See Suppl. material 4: Appendix 4.

Figures

Figure 112. Capsicum rhomboideum A reproductive branch B flower C calyx D eglandular trichome of the calyx E, F branched trichomes of the calyx G glandular trichome of the abaxial surface of the calyx H sector of opened corolla I eglandular trichome of the corolla lobes J gynoecium K fruit L fruit, in cross section M anatomical detail of the pericarp (note the absence of giant cells in the mesocarp) N seed O seed, in cross section P structure of seed coat at the seed margin Q structure of seed coat at the seed body R embryo A from Parra V. 089 B-D, G-J from Moore 3831 E, F from Haught & Svenson 11621 K-R from Acosta Solis 14234. Drawn by N. de Flury. Published in Hunziker (2001), reproduced with permission.

Figure 113. Capsicum rhomboideum A plant B main stem with lenticels flower buds C branch showing leaf pair dissimilar in shape and size D reproductive branch E flower bud F flower, in lateral view G flower, seen from behind H, J flower, in front view, showing connivent and not connivent anthers, respectively I node with a pendent flower and pedicels scars K mature fruits A, J from Barboza & Leiva Gonzalez 4854 B, D-F from Leiva Gonzalez 6585 C, G from Barboza et al. 5050 H, I, K from M. Scaldaferro 73. Photos by G. E. Barboza.

Figure 114. Distribution of C. rhomboideum and C. schottianum.