Senecio contumazensis J.Calvo & A.Granda, sp. nov. Type: Peru, Cajamarca, Contumazá, Cruz del Hueco, [7°23′S, 78°47′W], 2800 m, 26 May 1981, A. Sagástegui, S. López & J. Mostacero 9928 (holotype: US01837978!; isotype: HUT n.v.). Figs. 1, 3B.

Diagnosis.-This species differs from other species of Senecio in having the following combination of characters: leaves oblong-lanceolate, truncate at base, glabrescent to sparsely pubescent, radiate capitula arranged in corymbiform synflorescences, involucres composed of 13 bracts 4.7-5 mm long, and achenes with indumentum.

Description.-Suffrutescent plant ca. 1 m tall. Stem terete, barely striate, glabrous or scarcely pubescent at upper part, usually not branched. Leaves alternate, simple, petiolate, tending to form fascicles at primary cauline leaf axils; laminas 6.5-8 × 0.9-2.5 cm, oblong-lanceolate, base truncate and usually oblique, apex acute to attenuate, margins denticulate, glabrescent to sparsely pubescent, with secondary and tertiary venation noticeable on abaxial surface (dried specimens), chartaceous; petioles 1-3 cm long, sparsely pubescent. Synflorescences corymbiform; lower synflorescence bracts foliose, similar in shape to cauline leaves but shortly petiolate and auriculate or sessile and semiamplexicaul, upper synflorescence bracts linear-subulate. Capitula radiate on peduncles 4-15 mm long with 1-4 bracteoles. Involucre 5-5.5 mm long, 4-4.5 mm in diam., campanulate, glabrous; receptacle flat, fimbrillate; involucral bracts 13, 4.7-5 × 0.7-1.2 mm, linear-oblong, glabrous; supplementary bracts (calyculus) 5-6, 1.7-2.3 × 0.28-0.3 mm, linear, with scattered trichomes. Ray florets ca. 8, pistillate; corollas 10-11 mm long, limbs ca. 7 × 2 mm, 4-nerved, 3-toothed at apex, yellow. Disc florets ca. 34, hermaphrodite; corollas 6-6.8 mm long, tubular, limbs 3.3-3.5 mm long, 5-lobed, yellow; filament collars balustriform; anthers 2 mm long (including appendage), bases acute, yellowish, appendages ca. 0.4 × 0.2 mm; style branches truncate with a crown of sweeping trichomes, yellowish. Achenes ca. 2.6 mm long, ca. 0.5 mm in diam., cylindrical, 7-8-ribbed, with trichomes on ribs ca. 0.1 mm long (usually sparse), white; pappus 5-6 mm long, barbellate, white.

Distribution and habitat.-Species known from Contumazá Province and San Miguel Province in northwestern Peru (Fig. 2). It occurs at elevations of 2800-4000 m, in paramo-like areas referred as “jalca” or “páramo del norte peruano” (Weberbauer 1945; Sagástegui 1989). The “jalca” formations are usually interpreted as transitional alpine communities above 3,000 m, between the paramo of southern Ecuador and the puna of the central Andes (> 8° S), which longitudinally extend from the west of the Marañón River to the western foothills (Smith & Young 1987; Sánchez-Vega & Dillon 2006). The vegetation of the “jalca” is typically composed of tussock- or bunch-grasslands (“pajonales”) that include both herbaceous and woody plants.

Phenology.-Flowering from May to July.

Etymology.-The epithet refers to the Peruvian province of Contumazá, from where most of the studied collections come from. The province is located in the southwest of Cajamarca Department, in northwestern Peru.

Conservation status.-Senecio contumazensis is known from six collections representing five locations with an estimated EOO of 628 km² and an AOO of 24 km². None of the locations are in protected areas and the most important threat is habitat transformation for agriculture, as well as livestock grazing and illegal mining. Since a projected continuing decline of the habitat is inferred, the species is provisionally assessed as “Endangered” [EN B1ab(iii)+B2ab(iii)] in accordance with the IUCN Red List Categories and Criteria (IUCN 2012). The region where Senecio contumazensis thrives is known to harbor other species with a restricted distribution area (Weigend & al. 2005), e.g., Caxamarca sanchezii M.O.Dillon & Sagást. (Compositae), Jaltomata contumacensis S.Leiva & Mione (Solanaceae), Nasa contumazensis Weigend & E.Rodr. (Loasaceae), Ribes contumazensis Weigend (Grossulariaceae), Urtica peruviana Geltman (Urticaceae).

Notes.-The new species is very similar to the putative Bolivian endemic Senecio sepium, which is known only from La Paz Department (Cabrera 1985; Beck & Ibáñez 2014). The latter species, however, differs in having slightly longer involucral bracts (6-6.8 vs. 4.7-5 mm), remarkably broader supplementary bracts (see Fig. 3), and achenes with denser indumentum. The supplementary bracts are deep-purple to black in the upper half, whereas those of S. contumazensis are barely tinted at the apex. The petioles of S. sepium are usually winged and bear two auricles at the base. In contrast, the petioles of the new species are not winged, just somewhat broadened at the insertion point with the stem and the auricles usually lack. Senecio herrerae Cabrera from southern Peru and Bolivia (see Calvo & Beltrán, 2022) and S. pseudotites Griseb. from northwestern Argentina further differ from S. contumazensis in having 20-21 involucral bracts (vs. 13). Because of the aforementioned morphological characters and affinities, S. contumazensis is provisionally included within the series Otopteri (Cabrera 1985; Freire & al. 2014).

In the known distribution range of Senecio contumazensis, it also occurs S. betonicifolius DC. This species has similar leaves to the new species but it can be easily separated by the lianoid habit, the leaves with arachnoid indumentum on the abaxial surface, and the involucres tending to be nodding with florets that have penicillate style branches (Mostacero & al. 1184, US01846373).

Lastly, it should be noted that Senecio contumazensis has been confused with S. lancidentatus Cuatrec., a species known from the regions of Junín, Pasco, and Huánuco in central Peru. This latter species clearly differs in having long-pedunculate, discoid capitula arranged in very lax cymose synflorescences; the leaves are also remarkably smaller than in S. contumazensis.

Additional specimens examined.-PERU. Cajamarca: San Miguel, cerro Quillón (Agua Blanca), 7º01’S, 79º03’W, 5 Jul. 1986, J. Mostacero & al. 1260 (MO n.v., US); Contumazá, Pampa de la Sal (Cascabamba-Pozo Kuan), 7º23’S, 78º43’W, 13 Jun. 1981, A. Sagástegui & al. 10042 (US); Contumazá, jalca del Pozo Kuán, 7º24’S, 78º40’W, 27 Jun. 1983, A. Sagástegui, J. Mostacero & E. Alvitez 10778 (US); Contumazá, Ventarrón (Trinidad-Totorillas), 7º22’S, 78º58’W, 6 Jul. 1977, A. Sagástegui, E. Alvitez & J. Mostacero 8985 (US); Contumazá, Cascabamba (arriba de Contumazá), 7º22’S, 78º44’W, 8 Jul. 1977, A. Sagástegui, E. Alvitez & J. Mostacero 9027 (US).

Dendrophorbium pericaule (Greenm.) B.Nord., Compositae Newslett. 31: 22 (1997). Senecio pericaulis Greenm., Ann. Missouri Bot. Gard. 10: 89 (1923). Type: Ecuador, Azuay, province of Cuenca, Jul. 1864, W. Jameson s.n. (holotype: US00123338 [image!]).

Notes.-Originally described from one collection from the province of Huancabamba in the department of Piura, Senecio piurensis was defined as having: vegetative parts glabrous; stems simple, flexuous, herbaceous; leaves sessile, subamplectant or amplexicaul, repand-toothed at margins, up to 8 cm long; synflorescence corymbiform with divaricate branches and heterogamous capitula with 13 involucral bracts and 12 ray florets. In the discussion, the authors briefly mentioned its morphological affinities with the lianoid S. bullatus Benth. (= S. patens (Kunth) DC.) and S. gonocaulos DC. (≡ Pentacalia gonocaulos (DC.) A.Granda & J.Calvo), the former with discoid capitula and the latter with petiolate leaves. They also suggested similarities with S. cerrateae Cabrera (≡ Lomanthus cerrateae (Cabrera) B.Nord. & Pelser), a barely similar species except for its sessile leaves. Until now, the species has been considered endemic to northern Peru (Beltrán & al. 2006; Beltrán & Galán de Mera 2022).

Upon further study, the type material of S. piurensis reveals a rather suffruticose habit, the presence of trichomes on the leaf margins, and sagittate anther bases. It cannot be separated from Dendrophorbium pericaule, a species originally described within Senecio as S. pericaulis and known from southern Ecuador (Azuay, Cañar, Loja; Nordenstam 1999, see also examined material below). According to the information of the herbarium specimens and our direct observations in the field, the habit of D. pericaule can be erect or subscandent. Similarly, the leaf indumentum varies from pilose-hirsute (Lewis 2590; see also Fig. 4A) to glabrous with trichomes restricted to the margins (Madsen & al. 8004B; see also Fig. 4C). These latter forms are the ones that we studied from Peru and that have been referred to S. piurensis so far. Consequently, D. pericaule is a species distributed from the Ecuadorian province of Cañar to the departments of Piura and Cajamarca in Peru.

As pointed out by Nordenstam (1997, 1999), the inclusion of S. pericaulis in Dendrophorbium may be arguable in light of those forms that have a rather scrambling habit and resemble to members of Pentacalia Cass., characterized to have a lianoid habit (Robinson & Cuatrecasas 1978; Jeffrey 1992). Instead, Dendrophorbium is interpreted to include erect suffrutescent and tree-like species with usually moderately large, dentate leaves, and terminal synflorescences composed of radiate capitula, rarely discoid (Jeffrey 1992). As mentioned above, the scrambling habit is not consistent in D. pericaule (cf. Chacón 8, Lewis 2590, Minga & al. 2843) and strong morphological affinities with other members of Pentacalia cannot be established; instead, Greenman (1923) and Nordenstam (1997) related this species by the shape of the leaf base to S. amplexicaulis Kunth (cited as “S. amplexifolius HBK.” by Greenman), currently accepted as a member of Dendrophorbium, i.e., D. amplexicaule (Kunth) B.Nord. Because of the lack of further information that would help to settle the generic position of this species, we consider it appropriate to follow Nordenstam’s treatment and keep for now this species in Dendrophorbium. Molecular data might help to firmly set the position of this species.

Additional specimens examined.-ECUADOR. Azuay: Cuenca, río Tomebamba, 2º47’S, 79º7’W, 25 Sep. 2018, R. Arias & D. Orellana 201 (HA); Mazán, Dudahuaycu, 2º53’S, 79º9’W, 14 Jul. 1994, G. Chacón 8 (HA); between Oña and Cuenca, 3º22’S, 79º11’W, 9/10 Sep. 1923, A.S. Hitchcock 21600 (US); Cuenca Chaucha, Angas, 2º54’S, 79º19’W, 11 Jun. 2015, D. Minga & al. 2843 (HA); Garupamba, Fundación Gamma, 3º22’S, 79º12’W, 6 Sep. 2018, D. Minga, A. Verdugo & M. Jiménez 3655 (HA); vicinity of Cumbe, 3º5’S, 79º0’W, 25 Sep. 1918, J.N. Rose, A. Pachano & G. Rose 22983 (US); El Pongo, 3°7’53’’S, 79°4’48’’W, 24 Jun. 1999, F. Serrano, D. Minga & A. Verdugo 807 (HA); Sinincay, sector Cashaloma, 2º49’S, 79º2’W, 15 Jun. 2006, A. Verdugo & D. Minga 1219 (HA). Cañar: Dudas-Mazar, hacienda Dr. White, 2º32’S, 78º42’W, 31 Aug. 1999, F. Serrano, D. Minga & A. Verdugo 1076 (HA). Loja: Paltas, Guachanamá, cerro Guachahurco, parte alta cercana a las antenas, 4°2’10’’S, 79°52’20’’W, 22 Jul. 2023, N. Espinosa-Ortega, J. Calvo & G. Benítez 1039 (HUTPL); 15 km S of the Loja/Azuay border on road to Loja, 3º34’S, 79º10’W, 26 Sep. 1996, G.P. Lewis 2590 (AAU, LOJA); track from Universidad Nacional to Uritusinga, km 9.1, 4º0’S, 79º12’W, 7 May 1997, G.P. Lewis & al. 3255 (AAU, LOJA); rd. Loja-Las Achira (Uritusinga), km 10 from Universidad Nacional de Loja, 4º3’S, 79º13’W, 17 May 2001, J.E. Madsen, A. Byg & J. Gálvez 8004A (AAU, LOJA); rd. Loja-Las Achira (Uritusinga), km 10 from Universidad Nacional de Loja, 4º3’S, 79º13’W, 17 May 2001, J.E. Madsen, A. Byg & J. Gálvez 8004B (AAU, LOJA); Saraguro, Manú, Moras, 3º31’S, 79º26’W, 26 Jun. 1994, F. Vivar, Z. Aguirre & B. Merino 4261 (LOJA). Peru. Cajamarca: Jaén, Sallique, localidad La Cocha, 5º40’S, 79º14’W, 16 Jun. 1998, J. Campos & al. 4969 (US). Piura: Ayabaca, Cerro Negro (Meseta Andina), 5º0’S, 79º48’W, 23 Apr. 2004, A. Sagástegui & al. 17511 (US).