Fabiana australis Alaria, 2022

Alaria, Alejandrina, Chau, John H., Olmstead, Richard G. & Peralta, Iris E., 2022, Relationships among Calibrachoa, Fabiana and Petunia (Petunieae tribe, Solanaceae) and a new generic placement of Argentinean endemic Petunia patagonica, PhytoKeys 194, pp. 75-93 : 75

Fabiana australis Alaria nom. nov.

Figures 4 , 5

Petunia patagonica (Speg.) Millán. Darwiniana 5: 544 1941.

Basionym.

Nierembergia patagonica Speg. Revista Fac. Agron. Univ. Nac. La Plata 3: 357. 1897, non Fabiana patagonica Speg. (1897). Type: Argentina. Prov. Santa Cruz, Golfo de San Jorge, C. Ameghino, Febr. 1896, "in campis aridis glariosis" (holotype: LP 006658!).

Description.

Densely branched shrubs forming compact cushions of approximately 50 cm tall and up to 2.5 (-4) m in diameter; stems Bouchetia erect , leafy, glandular-pubescent, resinous. Leaves alternate but apparently verticillated by shortening of the internodes, sessile, fleshy, glandular; linear, elliptical or obovate, blade 3-4 (5) mm long by 1-2 mm wide. Flowers terminal, solitary, Bouchetia erect ; flowering pedicels of 4-6 mm. Calyx tubular or slightly campanulate, (8-) 11-12 mm long, externally with dense glandulous indumentum, internally with scattered glandulous pubescence, short and broadly triangular lobes, 2-3 mm long by 2-3.5 mm wide, almost as long as wide. Corolla yellow with marked violet nerves, but also with color variation from light purple to deep violet, infundibuliform, 20-25 (-30) mm long, externally glandular, broad triangular lobes 2.5-5 mm long by 6-10 mm wide. Stamens heterodynamous, adhered to the middle third of the corolla, about 9 mm from the base of the corolla; filaments 2 short and 3 long, somewhat geniculate at the point of insertion with short glandular hairs scattered at the base; ellipsoid anthers of 1-1.5 mm. Ovary obovoid, 2.5-3 mm long, 1.2-1.5 mm wide, with nectariferous disc surrounding the base, 10-15 mm long style, truncated stigma, shallowly split. Capsule ovoid, 5-9 mm long by 3-5.5 mm wide. Seeds numerous, polyhedrical in shape, 2-2.5 mm long.

Common name.

“Mogote” meaning mound shape (Santa Cruz: Arroyo 1999)

Geographical distribution and habitat.

Endemic to Patagonian Argentina, in the provinces of Chubut and Santa Cruz, from 90 to 700 m elevation, inhabiting dry and cold environments, on stony, sandy soils, sometimes rich in silt and clay, poor in organic matter. It forms large populations of cushion shrubs with numerous showy flowers (Fig. 6 ).

Taxonomic notes.

The epithet autralis was selected based on the restricted distribution of this species in southern Argentina. It is not possible to use Fabiana patagonica as a specific epithet in Fabiana , because it is already in use in Fabiana patagonica Speg. Fabiana australis is one of the southernmost species of the genus. It shares with F. foliosa and F. nana a similar habit forming dense cushions in dry, cold, and poor soils of Patagonian Argentina.

Representative specimens examined.

Argentina: Santa Cruz: Dpto. Corpen Aike, G.E. Barboza 3706 (CORD); O. Boelcke 16264 (BAB); A.A. Cocucci 3684 & 3723 (CORD); M.N. Correa 6527 (BAB); R.H. Fortunato 7492 (BAB); C.A. O’Donell 3794 (CORD00015699). Dpto. Deseado, L.M. Bernardello & M.R. Figueroa Romero 335 (CORD00015696!); O. Boelcke, 12214 (BAB); A.A. Cocucci 4175 (CORD); M.N. Correa 2644 & 6697 (BAB); B.E Leuenberger 4100 (B: D-14191 Berlin); M.C. Romanczuk 989 (UEC); F.B. Vervoorst 5658 (CORD 00015700!). Dpto. Güer Aike, A. Soriano 5062 (BAB). Dpto. Lago Argentino, G.E. Barboza 3732 (CORD); A.A. Cocucci 471 (CORD 00015694!); R.H. Fortunato 4967 (BAB, ARIZ, NY, HRP); C. Guerrido 785 (SI). Dpto. Magallanes, G.E. Barboza 3704 (CORD); O. Boelcke 15394 (BAB); Iter Patagonicum 762 L. Hauman & C.M. Hicken (SI); B.E. Leuenberger & S. Arroyo 3710 (CORD 00015698!). Dpto. Rio Chico , M.N. Correa & E.G. Nicora 3517 (BAB; CORD 00015697!); G.E. Barboza 3696 (CORD); G.E. Barboza 3746 (CORD; SI 063988 !); G.E. Barboza 3748 (CORD); O. Boelcke 12810 (BAB); J.M. Bonifacino 2986 (SI); C.M. Hicken 10245 (SI); F.O. Zuloaga 13978 & 13991 (SI). Valle del Río Santa Cruz C. Burmeister s.n. & 95 (SI); M. Gentili 330 (BAB); J. Koslowsky 122 (CORD 00015695!). Without locality A. Donat 206 (SI); P.K.H. Dusén 5496 (SI); E. Molina Massey 31 (SI); Tessleff 5496 (SI) . Chubut: Dpto. Futaleufú, A.A. Cocucci 3997 (CORD 00022097!); Dpto. Paso de Indios , S.C. Arroyo 208 (BAB, LIL, K); Dpto. Sarmiento, A. Alaria 321 (MERL). Dpto. Languiñeo, A. Alaria 324 (MEN) .

Taxonomic characters differentiating Calibrachoa , Fabiana , Petunia , and Nierembregia are described in the following key. Geographic distribution of the four genera and Petunia patagonica , as well as photographs of flowers and seeds of representative species of each genus, are illustrated in Figure 4 .

Figures

Figure 4. Geographic distribution of the genera Fabiana, Calibrachoa, Petunia, and Nierembregia, and the species Fabiana australis Alaria. Flowers and seeds of representative species: Fabiana patagonica Speg (first flower scale: 2.5 mm, second flower scale: 5 mm, seed scale: 0.5 mm, surface details magnifications 600 x and 1,500 x); Calibrachoa parviflora (Juss.) D'Arcy (first flower scale: 2.5 mm, second flower scale: 5 mm, seed scale: 0.5 mm, surface details magnifications 500 x and 1,500 x); Petunia axillaris (Lam.) Britton, Sterns & Poggenb. (first flower scale = 5 mm, second flower scale: 10 mm, seed scale: 0.5 mm, surface details magnifications 600 x and 1,500 x); Nierembergia pulchella Gillies ex Miers (first flower scale: 5 mm, second flower scale: 10 mm, seed scale: 0.5 mm, surface details magnifications 600 x and 1,500 x). Photograph IBODA, Flora Argentina database.

Figure 5. Fabiana australis Alaria. A plant B flowering branch C flower D corolla deployed showing gynoecium and stamens of different length E stigma F anthers G capsule H capsule showing seeds, I capsule valve J seeds. Scale bars: 10 mm (A); 4 mm (B); 5 mm (C); 2.5 mm (D); 1 mm (E); 0.5 mm (F); 2 mm (G, H). Illustration by Cecilia Scoones.

Figure 6. Fabiana australis Alaria. Plants habit and flower details (Zuloaga FO 13991, SI). Photograph IBODA, Flora Argentina database.