Solanum comptum, C. V. Morton, Revis.

Wahlert, Gregory A., Chiarini, Franco E. & Bohs, Lynn, 2015, A Revision of Solanum Section Lathyrocarpum (the Carolinense Clade, Solanaceae), Systematic Botany 40 (3), pp. 853-887 : 870-872

3. SOLANUM COMPTUM C. V. Morton, Revis. Argentine Sp. Solanum : 230. 1976. — TYPE: ARGENTINA. Corrientes: Departamento Mburucuyá, Establecimiento “ La Yerba ”, 24 Nov 1944 (fl), G. J. Schwartz 214 (holotype: NY– NY00139103 !; isotypes: A, LIL– LIL001443 [scan!], NY– NY00139104 !).

Erect to decumbent perennial herb up to 0.6 m tall; stems usually branched at the base, often rooting at the nodes; roots producing buds. Stems sparsely to densely pubescent with stellate hairs showing a continuum of morphology from small subsessile to short-stalked hairs (the stalks up to 0.2 mm long, 0.05–0.1 mm wide at the base, with (4)6– 8 subequal lateral rays spreading 0.5–1 mm in diameter, the central ray 1-celled, up to 0.5 mm long) grading into longstalked hairs (the stout prickle-like stalks up to 6 mm long, up to 0.4 mm wide at the base, with (4)6–8 subequal lateral rays spreading up to 2 mm in diameter, the central ray 1–3-celled, up to 3.2 mm long), sparsely to moderately armed with straight tapered prickles up to 7 mm long. Sympodial units 2- to 3-foliate, sometimes plurifoliate, the leaves not geminate. Leaves simple, the blades 5–11 × 3–10.5 cm, broadly deltoid-ovate in outline, moderately to densely stellatepubescent abaxially and adaxially with sessile to short-stalked stellate hairs up to 1.2 mm in diameter, with (4)6–8 lateral rays, the central ray 1-celled and up to 1.0 mm long, sparsely to moderately armed with prickles up to 9 mm long on the major veins abaxially and adaxially; base cordate to cuneate, rarely truncate, equal to unequal, often with one side offset up to 1 cm from the other, often with open sinuses; margin irregularly serrate to shallowly and irregularly lobed; apex obtuse to rounded; petioles 2–7 cm long, sparsely to moderately stellate-pubescent with hairs like those of the stem, moderately armed with prickles up to 12 mm long. Inflorescence 5–15 cm long, extra-axillary, unbranched or forked, with 3–10 flowers, weakly andromonoecious with the 2–5 proximal flowers hermaphroditic and the (0)3–6 distal flowers staminate, the axes moderately stellate-pubescent, sparsely armed with prickles up to 5.4 mm long; peduncle 3–7 cm long; pedicels 1.5–3.5 cm long in flower and fruit, deflexed downward in fruit, spaced 0.5–1.5 cm apart, articulated at the base, sparsely to moderately stellate-pubescent, sparsely armed with prickles up to 5.5 mm long. Calyx 4.5–8 mm long, the tube 1–3 mm long, the lobes 2.5–6 × 2–2.5 mm, deltate-lanceolate, the apex acute-acuminate, densely pubescent with sessile stellate hairs abaxially, glabrous adaxially, sparsely to moderately armed abaxially with prickles up to 5.5 mm long; fruiting calyx strongly accrescent and completely covering the fruit, 7–15 mm long, the tube ca. 4 mm long, the lobes 5–6 × 4–5 mm, narrowly triangular, moderately stellate-pubescent, sparsely armed with prickles up to 5 mm long. Corollas 2–3 cm in diameter, 13–18 mm long, stellate to rotate-stellate, chartaceous, light blue or sky blue, the tube 5–8 mm long, the lobes 5–10 × 5–10 mm, deltate, the apex acute, moderately to densely stellatepubescent abaxially, glabrous adaxially. Stamens with filaments 0.8–2 × 0.15–0.4 mm; anthers subequal, 3.5–10 × 0.8–2 mm, narrowly lanceolate, weakly connivent, yellow, the pores directed distally. Ovary 1–1.5 × 1–1.5 mm, subglobose, minutely glandular-puberulent at apex; style 7–12 × 0.3–1 mm, cylindrical, straight, glabrous, exserted in hermaphroditic flowers; stigma capitate. Fruits 1–1.8 × 1–2 cm, globose to subglobose, the apex obtuse, light green with darker green mottling when young, yellow at maturity, glabrous, the rind tough. Seeds ca. 3.5 × 2.5–4 mm, flattened-reniform, lenticular, yellow, the surface finely foveolate.

Distribution and Habitat — Solanum comptum is distributed in Chaco, Corrientes, and Formosa provinces of northeastern Argentina and in the Alto Paraguay, Boquerón, Misiones, and Ñeembucú departments of Paraguay ( Fig. 6 ) at elevations from 30– 160 m. This weedy species grows in the Chaco vegetation formation and is commonly found on roadsides and other disturbed environments. It has been reported growing in clays, sands, and in inundated areas such as river banks. Disturbance of its bud-producing roots seems to promote its propagation, and it often becomes a pest in areas such as roadsides, waste areas, and cultivated areas.

Phenology — The species flowers between October and March and fruits between October and May.

Conservation Status — Solanum comptum is known from ca. 21 populations in Paraguay and northern Argentina. This weedy and invasive species grows in disturbed habitats and it is doubtful that any significant reduction in population size or locations will occur. With an extent of occurrence of ca. 200,000 km 2 and area of occupancy of 464 km 2, Solanum comptum is assigned a preliminary conservation status of “least concern” (LC).

Etymology — The epithet comptum means ornamented or adorned, particularly with regard to a headdress. Morton (1976) did not explain the meaning of the name, however, it most likely refers to the stellate hairs with stout, prickle-like stalks. These hairs appear to be developmentally intermediate between stellate hairs and true prickles lacking rays at their tips. Alternatively, the name could possibly refer to the densely stellate-pubescent and armed accrescent fruiting calyces that completely cover the mature fruit.

Vernacular Names — The common name mero-rá was recorded from L. Bernardi 18421 collected in Ñeembucú department in Paraguay. Common names recorded for Solanum comptum in Argentina are punguo, tutía-poñi, and melora ( Matesevach 2002; Barboza 2013).

Chromosome Number — Solanum comptum has been shown to be a tetraploid with a sporophytic chromosome count of 2 n = 48 (G. E. Barboza et al. 999; G. E. Barboza et al. 1001; Chiarini 2007).

Notes — In habit and most vegetative and reproductive characters, Solanum comptum is similar to S. hieronymi but can be distinguished by its light blue corolla (vs. white in S. hieronymi ), smaller (0.8–1 × 0.7–1.3 cm) globose fruits completely covered by the accrescent fruiting calyx [vs. larger (1.5–2.2 × 1–2 cm) depressed globose fruits with a weakly accrescent fruiting calyx], and small stellate hairs with central rays consisting of 1–2 cells that are shorter or equal to

the lateral rays (vs. central rays of 1–4 cells that are longer than the lateral rays). Another diagnostic character for S. comptum is the presence of large stellate hairs with stout yellow prickle-like stalks up to 6 mm long and terminated with 4–8 lateral rays and a 2-celled central ray. In S. comptum , these prickle-like stellae are sparsely to moderately distributed on the stem, petioles, leaf blades, inflorescence axes, and pedicels, and densely so on the calyces. In S. hieronymi , prickle-like stellae are absent or sometimes sparsely distributed on the petioles and calyces. Finally, S. comptum lacks the short (up to 0.3 mm long) unbranched glandular hairs that are moderately to densely distributed on plants of S. hieronymi .

Additional Specimens Examined — ARGENTINA. Chaco: Resistencia, Barranquera, 10 Mar 1947 (fl, fr), M. R. Malvárez 1153 ( LIL); Río Bermejo, Las Palmas, 15 Mar 1947 (fl, fr), M. R. Malvárez 1299 ( LIL); 12 de Octubre (Campo del Cielo), General Capdevila, 14 Dec 1946 (fl), C. Schulz 987 ( LIL); Dpto. Primero de Mayo, Colonia Benítez, s.d., A. G. Schulz 2058 ( CTES, MO). Corrientes: Goya, Arroyo Guazú, 29°50′26″S, 59°24′24″W, 31 m, 3 Dec 2002 (fl), G. E. Barboza et al. 356 ( CORD); a 14 km de Corrientes, rumbo a Riachuelo, 27°33′05″S, 58°45′02″W, 4 Dec 2002 (fl), G. E. Barboza et al. 372 ( CORD); San Cosme, a 3 km de Puerto González, 5 Dec 2002 (fl, fr), G. E. Barboza et al. 384 ( CORD); Capital, Camino hacia el aeropuerto, 13 May 2004 (fr), G. E. Barboza et al. 999 ( CORD); Capital, Perichón, 29°24′34.4″S, 58°45′09.3″W, 13 May 2004 (fr), G. E. Barboza et al. 1001 ( CORD); San Cosme, desde Paso de la Patria rumbo a Puerto González, 27°18′42″S, 58°29′22″W, 13 May 2004 (fr), G. E. Barboza et al. 1005 ( CORD); Capital, Ciudad de Corrientes, parque Mitre, 14 Dec 2000 (fl), F. Chiarini 406 ( CORD); Dpto. Goya, por RN 12, en la entrada a Goya, 29°10′28.9″S, 59°14′45.5″W, 39 m, 29 Feb 2012 (fl), F. Chiarini & G. A. Wahlert 823 ( CORD, UT); Paso de La Patria, 6 Jan 1975 (fl), A. R. Cuezzo et al. 10967 ( LIL); Dpto. San Cosme, Ensenada, 27 Feb 1945 (fr), R. Huidobro 1805 (A-n.v., LIL-n.v., NY); same locality, 28 Feb 1945 (fr), R. Huidobro 1842 (A-n.v., LIL-n.v., NY); Dpto. San Cosme, km 10, 7 Apr 1945 (fr), R. Huidobro 1902 ( NY); Empedrado, Río Empedrado, RN 12, 29 Sep 1971 (fl), A. Krapovickas et al. 19895 ( LIL); Dpto. Capital, Corrientes, 15 Oct 1987 (fl, fr), A. Krapovickas 41919 ( FCQ, MO, NY); Dpto. Mburucuyá, Estancia “Santa Teresa”, 21 Dec 1951 (fl), T. M. Pedersen 1405 ( NY, MO, P); Dpto. Empedrado, Estancia “La Yela”, 8 Jan 1983 (fr), T. M. Pedersen 13485 ( NY [2 sheets], MO); orillas del Paraná, Nov 1936 (fr), A. P. Rodrigo 903 ( NY); Bella Vista, 13 Oct 1974 (fl), A. Schinini & C. L. Cristóbal 9915 ( CTES); Capital, ciudad de Corrientes, 17 Oct 1997 (fl), A. Schinini & M. G. López 32712 ( CTES, FCQ, NY); Saladas, Santo Domingo, 21 Jan 1950 (fr), G. J. Schwarz 9292 ( CORD). Formosa: Capital, en la plaza, 14 Mar 1885 (fl), F. Kurtz 1389 ( CORD).

PARAGUAY. Alto Paraguay: Palmar de las Islas, Estancia San José, 1500 m al W del casa, 7 Jan 1998 (fl, fr), R. Insua 6 ( FCQ); Ftín. Carlos A. López, Pitiantuta, 14 Oct 1992 (fl, fr), F. Mereles & R. Degen 4719 ( CTES- n.v., FCQ, MO); Parque Nacional Defensores del Chaco, 20°35′43″S, 59°51′42″W, 131 m, 13 Aug 1998 (fl), F. Mereles et al. 7347 ( FCQ); Fin de Parque Nacional, 20°30′07″S, 59°48′44″W, 25 Nov 2002 (fl), F. Mereles et al. 8908 ( FCQ); Estancia San Miguel, Palmar de las Islas, 5 Mar 1989 (fl), L. Ramella & F. Mereles 2490 ( CORD). Boquerón: 75 km al N de Tte. Montanía, Tyto. Montanía-Madrejón, a 75 km, 15 Dec 1993 (fl, fr), R. Degen & F. Mereles 3094 (CTES-n.v., FCQ, MO); Tte. 1°A. Picco, 20°59′ S, 60°31′W, 59 m, 21 Oct 1987 (fl), R. E. Spichiger et al. 2279 ( CORD, FCQ). Chaco: Palmar de las Islas, borde de la laguna Palmar, 5 Mar 1989 (fl, fr), F. Mereles 2705 ( FCQ). Distrito Capital: city of Asunción, Villa Morra, on Dr. Quesada between Cruz del Chaco and General Gaulle, 25°17′50.9″S, 57°34′41″W, 115 m, 26 Nov 2003 (fl, fr), L. Bohs 3193 ( NY, UT). Misiones: between San Juan Bautista and road San Ignacio-Pilar, Talaty, 8 km SE of San Juan Bautista, 26°40′S, 57°14′W, 23 Feb 1994 (fr), E. M. Zardini & T. Tilleria 38540 (AS-n.v., NY, MO). Ñeembucú: Curupayty, Humaitá, 9 Nov 1978 (fl), L. Bernardi 18421 ( NY). Presidente Hayes: along Ruta Trans-Chaco NW of Villa Hayes, near Arroyo Ka’ I, 23°57′58.9″S, 58°25′40.6″W, ca. 90 m, 29 Nov 2003 (fl), L. Bohs et al. 3203 ( UT).

Figures

FIG. 6. Distribution of Solanum comptum and S. hieronymi.