Arnaldoa Cabrera (1962: 39)

Ferreira, Paola De Lima, Antonelli, Alexandre & Groppo, Milton, 2021, Touch me carefully: a step towards understanding morphological diversity in the South American spiny sunflowers (Compositae, Barnadesioideae), Phytotaxa 518 (2), pp. 109-142 : 114-116

2. Arnaldoa Cabrera (1962: 39)

Type: — Arnaldoa weberbaueri (Muschl.) Ferreyra

Arching shrubs, up to 4 m tall, multistemmed. Stems erect or decumbent, much-branched, lenticelate, cylindrical, glabrous, velutinous or densely tomentose, axillary spines in pairs, straight, convergent or divergent, glabrous or tomentose at base and becoming glabrous towards the apex. Leaves alternate, petiolate, persistent or deciduous, blade elliptic, ovate or oblate, coriaceous, pale or lustrous, adaxially glabrous to tomentose, abaxially glabrous to densely tomentose, villous, floccose, lanose, apex acute or obtuse, margin flat or slightly revolute, glabrous or ciliate, apex mucronate or spiny; venation actinodromous with 3 basal suprabasal nerves. Capitulescence terminal, monocephalous. Capitula 30–95-flowered, homogamous, discoid, sessile, involucre campanulate, 8–15 series, phyllaries coriaceous, brown or black, erect or reflexed, glabrous to densely tomentose, ovate—triangulate grading to lanceolate, apex mucronate or spiny, margin flat, ciliate. Receptacle flat, pilose. Flowers isomorphic, bisexual, corolla subbilabiate (4+1), 5-lobed, red, purple, orange or white, villous. Anthers 5, apical appendage lanceolate or obtuse, basal appendage truncate, caudate, calcarate, inserted at the throat of the corolla, filaments free, glabrous or villous. Style cylindrical, red, purple, orange, white. Cypselae turbinate or cylindrical, densely villous. Pappus plumose, slightly shorter or equal to corolla length, bristles whitish. Pollen with intercolpal depression, microechinate (Suessy & Urtubey 2007). Chromosome number = 24–27 ( Stuessy & Sagástegui 1993).

Fig. 3c–d ; 10f .

Distribution and habitat: — Arnaldoa comprise three shrubby species found in Monte Bajo Puna vegetation (shrubby dry slopes) above an altitude of 1,500 m in northern Peru and southern Ecuador (Stuessy & Sagástegui-Alva 1993, Ulloa et al. 2002).

Notes: — Arnaldoa is morphologically close to Chuquiraga , sharing the shrubby habit, discoid capitula, colorful corollas and stigma, long caudate anthers, and microechinate pollen. However, Arnaldoa is distinguished by the subbilate corolla (vs. tubular in Chuquiraga sensu Ezcurra 1985 ) and stamens inserted on the throat of corolla tube (vs. base of corolla in Chuquiraga ). Phylogenetic hypotheses based on molecular data recovered Arnaldoa as closely related to Fulcadea ( Gustafsson et al. 2001, Gruenstaeudl et al. 2009, Funk & Roque 2011, Ferreira et al. 2019). Although the morphological differences between Arnaldoa and Fulcaldea are remarkable, Arnaldoa by having solitary capitula with 30–95-flowered, subbilabiate corollas, caudate anthers, microechinate pollen, cylindrical style vs capitula arranged in synflorescence with 1-flowered, tubular corollas, ecaudate anthers, spinulose pollen, and swollen style below the branching point in Fulcaldea , they share the arching shrubby habit, red corollas, and geographical distribution in southern Ecuador and Northern Peru.

Iconography: —Stuessy & Sagástegui-Alva (1993), Ferreyra (1995), Ulloa et al. (2002).

Accepted species:—2.1 Arnaldoa argentea C. Ulloa, P. Jørg. & M.O. Dillon ; 2.2. Arnaldoa macbrideana Ferreyra ; 2.3. Arnaldoa weberbaueri (Muschl.) Ferreyra.

Selected specimens examined: — ECUADOR. Loja: Amaluza, road to the antennas above town, at the top, 2400 m, 4°33’58”S, 79°26’26’’W, 05 November 2000, P.M. JØrgensen 2234 (QCNE, MO, WU; 2.1). Bellavista, Vicinity of Bellavista , at “Las Antenas” (7 km from Amaluza ), 2400 m, 04°33’S, 79°26’W, 14 August 2001, J.E. Madsen 8341 ( MO; 2.1). Vicinity of Bellavista , at “Las Antenas” (6–7 km from Amaluza), 2200–2300 m, 04°33’S, 79°27’W, 31 may 2001, J.E. Madsen 8175 ( MO; 2.1) . PERU. Amazonas: Chachapoyas, western base of the Cerros Calla Calla , 22km east of Balsas on the road to Leymebamba , 1940 m, 30 May 1964, P.C. Wright 5454 (K, MO; 2.3). Cordillera de Calla Calla , Balsas-Leymebamba road near km 359, 6400 ft. (c. 1951m) 9 July 1977, T. Ducan 2602 ( MO; 2.3). Ancash: Chingas , north of the village of Llamellin , on the west flanks of the Rio Marañón , 2669 m, 09°04’08’’S, 76°59’39’’W, 27 May 2011, E. Gagnon 3157 (K; 2.3). Huari, Falda de los Cerros de los rios Mosna y Puchca, 2400–2800 m, 27 May 1962, M.Z. Agnes 41 ( MO; 2.3). Cajamarca: Celendín , Rio Marañon valley , Celedín-Balsas road, 25 km, and onward from Celendín , 1000–2500 m, 06°51’S, 78°05’W, 16 July 1983, D.N. Smith 4323 ( MO; 2.3). Celendín , Had. El Limón (Celendín-Balsas), 2150 m, 5 May 1970, A. Sagastégui A. 7410 (US; 2.3). Celendín , Hacienda Limon, 33 kms E of Celendín on road to Rio Marañon , 2050 m, 10 July 1992, T.F. Stuessy 12524 ( WU; 2.3). Lambayeque: Lambayeque, Alredores del Cuello Porculla , 1800 m, 24 July 1991, J. Mostacero L. 2296 ( MO; 2.2). Lambayabeque, Road from Olmos to Abra Porculla, 1500 m, 22 February 1976, T. Plowman 5516 ( US; 2.2). Lambayabeque, west side Abra Porculla Km. 35 east of Olmos. Mesones-Muro Highway between Olmos y Río Maranon, 1650 m, 26 September 1957, C. Hutchison 1379 (US; 2.2). Libertad: Pataz, road Buldibuyo to Tayabamba, dryish inner andean valley, mostly cultivated, but steeper slopes with scrub forest, 3141 m, 08°12.571’S, 77°19.665’W, 24 April 2004, M. Weigend 8031 (B; 2.3). Pataz, Huancaspata-Puente Mamahuaje, 3000 m, 26 June 1974, A. López M. 8218 ( MO; 2.3). Bolivar, District La Longotea , section Pampa Colorada, 1914 m, 13 May 2011, 07°02’31’’S, 77°55’08’’W, R.W. Bussman 16871 ( MO; 2.3). Piura: Abra de Porculla , entre Olmos y Jaen, 2100–2200 m, 28 June 1959, R. Ferreyra 13731 ( MO; 2.2). Bajando Abra de Porculla y Jaen , cerca del Abra, 1800–1900 m, 26 June 1959, R. Ferreyra 13628 ( MO; 2.2) .

Figures

FIGURE 3. Archidasyphyllum and Arnaldoa. A–B: Archidasyphyllum diacanthoides. A: Habit. B: Multi-stemmed tree with fasciculate spines. C–D: Arnaldoa weberbaueri. C. Habit. D. Capitulum. Photos by Marcelo Monge (A–B), Gari Ccana-Ccapatinta (C), and Daniel Montesinos (D).

FIGURE 10. Geographical distribution for the genera of Barnadesioideae. A: Dasyphyllum. B: Chuquiraga. C: Barnadesia (red dots) and Huarpea (blue triangle). D: Doniophyton (blue triangles); E: Archidasyphyllum (blue triangles); Fulcaldea (blue triangles)—these words (triagle) in plural (triangles).