Gutierrezia ameghinoi Spegazzini (1897: 527)

Ratto, Francisco & Bartoli, Adriana, 2015, The resurrection of Gutierrezia ameghinoi (Asteraceae, Astereae, Solidagininae), a species from Patagonia, Argentina, Phytotaxa 220 (3), pp. 295-300 : 296

Gutierrezia ameghinoi Spegazzini (1897: 527) . Fig. 1 .

Type:— ARGENTINA. Prov. Santa Cruz, “rarissime in pratis glareosis secus Rio Deseado, anno 1894”, C. Ameghino 94 ( LP!). Gutierrezia paniculata var. patagonica Spegazzini (1897 b: 608) . Gutierrezia brachyris var. patagonica (Speg.) Macloskie (1905: 780) . Type:— ARGENTINA. “ Chubut, Moyano, 1897” ( LP!).

Subshrubs 10–20 (–25) cm, much branched at the base. Stems erect, ribbed, glandular, leafy. Leaves subcoriaceous, sessile, entire or irregularly toothed at margin, with glandular, sessile and stipitate trichomes on both blade surfaces, elliptic-spatulate leaves, attenuated in a pseudopetiole, 15–35 mm × 3– 2 mm, obtuse. Heads radiate, heterogamous, sessile, 12–16 mm diam., arranged in corymbose cymes at the stem apex, with 1 or 2 elliptic bracts 2–3 mm long. Involucre cylindrical or cylindrical-turbinate, resinose, 6 mm × 4 mm. Receptacle flat or slightly convex, naked, pitted, pilose. Phyllaries in 3 series; outer phyllaries oblong, glandular-acuminate; inner phyllaries narrowly obovate, apiculate. Ray florets 6 to 9, pistillate, with lamina yellow, elliptic to elliptic-spatulate, 4–7 mm × 2–4 mm; style with branches linear-elliptic, apex acute, papilose. Disk florets 8 to 12, perfect, with corolla yellow, 4 mm, tubular, with an abruptly ampliated throat. Anthers rounded at the base; apex of connective ovate to ovate-elliptic; style branches linear-elliptic acute, with papillose trichomes on the outer side. Achenes grey, cylindrical or obovate-cylindrical, ribbed, densely sericeous, 2–3 mm long; pappus of 8–12 linear-elliptic, erose-margined scales, ca. 1–1.5 mm long in ray florets and 2–3 mm long in disk florets.

Distribution and habitat:—The species occurs in Argentina, in the provinces of Chubut and Santa Cruz, particularly in the Patagonian Central District of the Patagonian phytogeographic province ( Cabrera 1971b). It grows in plains on sandy, loose soils from the sea level to 250 m s. l. together with other composites as Ameghinoa patagonica Speg. , Brachyclados caespitosus (Phil.) Speg. , Chuquiraga avellanedae Lorentz , Nassauvia glomerulosa (Lag. ex Lindl.) D. Don and Nardophyllum bryoides (Lam.) Cabrera , and also several species of Jarava Ruiz & Pav. ( Poaceae ). Figs. 2 and 3 .

Phenology:— Gutierrezia ameghinoi blooms from January to March.

Additional material examined:— ARGENTINA. Chubut. Gaiman. Gaiman, camino al dique F. Ameghino, December 1981; ibídem, Cabrera et al. 33296 (SI); ibídem, 9 December 1984, T. F. Stuessy et al. 6937 (SI). Santa Cruz. Deseado. Puerto Deseado, 26 March 1917, Bonarelli s.n. (BA); Puerto Deseado, 1 April 1917 (SI 138195); Puerto Deseado, March 1928, Guiñazú s.n. (BA); 29 December 1938, W. J. Eyerdam 23871 et al. (SI); Puerto Deseado, 17 January 1965, E. Ancibor & A. Vicinis s. n. (BAA 4429); Ruta 281 km 14, alrededores de la gruta de Lourdes, 8 January 1967, O. Boelcke et al. 12149 (BAA, BAB, SI); 35 km de Jaramillo, camino al bosque petrificado, 10 January 1967, O. Boelcke et al. 12167 (BAB); 35 km de Jaramillo camino al bosque petrificado, 10 January 1967, O. Boelcke et al. 12168 (SI); Puerto Deseado, zona Sorrel, 9 December 1970, S. Crespo & N. Troncoso 1704 (BAB, SI); RN3, Puerto Deseado, frente a la isla 5ta, 8 m s.m, 18 December 2012, E. Urtubey 608 & E. M. Baztarrica (SI); de Tellier a Puerto Deseado, 67 m s.m. 16 January 2013, E. Urtubey 807 (SI); Puerto Deseado, 81 m s. m., 24 January 2015, F. Ratto 88 (BAA); Puerto Deseado, 74 m s. m., 24 January 2015, F. Ratto 89 (BAA); Puerto Deseado, 24 m s. m., 25 January 2015, F. Ratto 90 (BAA); Puerto Deseado, 36 m s. m., 25 January 2015, F. Ratto 91 (BAA).

Figures

FIGURE 1. Gutierrezia ameghinoi (Asteraceae): (A) plant, (B) cauline leaf, (C) head, (D) outer phyllary, (E) middle phyllary, (F) inner phyllary, (G) ray floret with fruit and pappus (H) disk floret with fruit and pappus.

FIGURE 2. Gutierrezia ameghinoi (Asteraceae): (A) growing in the field, (B) inflorescence detail, (C) population.All photos were taken in Puerto Deseado, Santa Cruz Province by E. R. Morala.

FIGURE 3. Distribution map of Gutierrezia ameghinoi. The stars show the Departments where this species was collected.