Parodia mueller-melchersii (Frič ex Backeb) N.P. Taylor, Bradleya

Pittella, Renan Silveira, Santos, Thamiris Barbosa & Farias, Hélio Ramirez, 2020, New record and expansion of the geographic distribution of Parodia mueller-melchersii (Frič ex BAckeb.) N. P. TAylor (CActAceAe) in the Southern region of Rio GrAnde do Sul, BrAZil, Iheringia, Série Botânica (e 2020009) 75, pp. 1-6 : 2-5

Parodia mueller-melchersii (Frič ex Backeb) N.P. Taylor, Bradleya ; Yearbook of the British Cactus and Succulent society 5:93. 1987.

Synonyms: Notocactus eugeniae Vliet , Notocactus gutierrezii W.R. Abraham , Notocactus mueller-melchersii Fric ex Backeb , Notocactus rutilans Daniker & Krainz , Notocactus veenianus Vliet , Parodia mammulosa subsp. eugeniae (Vliet) Hofacker , Parodia mueller-melchersii subsp. gutierrezii (W.R. Abraham) Hofacker , Parodia mueller-melchersii subsp. winkleri (Vliet) Hofacker , Parodia rutilans (Daniker & Krainz) N.P. Taylor , Parodia rutilans subsp. veeniana (Vliet) Hofacker.

New record: Brazil, Rio Grande do Sul, Jaguarão (32º33’57”S 53º22’33”W), 3º Subdistrito Quilombo, observed by Renan Pittella, Thamiris Barbosa e Hélio Ramirez, 18.VIII.2018 (population size ca. 180 individuals) ( Fig. 1 ) .

Voucher: Parodia mueller-melchersii , BRASIL, RIO GRANDE DO SUL, Jaguarão, 3º Subdistrito, Fazenda Rincão da Coronilha , 22.X.2019, R. Farias-Singer, R. Pittella, H. Ramirez, P. Martins & F. S. Petry 2.051 (HAS 96644) .

Additional specimens examined: BRASIL, RIO GRANDE DO SUL, Santana do Livramento, road to Cerros Verdes, 5.XII.2005, Machado M. 692 (HUEFS 105018 [image]); road to Cerros Verdes , 15.XI.2006, Machado M. 893 (HUEFS 135168 [image]); Uruguaiana , Estancia Juquiri , 21.X. 2009, Ari Delmo Nilson e Ricardo Aranha Ramos s/nº (FZB/ RS CAC329 ); No location data, 4.V.1964, No collector data (WAG 1878616 [image]) ; SOUTH AMERICA, 16.V.1969, Buining s/nº (WAG 1878617 [image]); No location data, 4.IV.1966, B. K. Boom 44650 (WAG 1918811 [image]) .

Description: Solitary or clustered cactus, terrestrial, elongated globular shape, 10-15 cm in height x 10-15 cm in diameter, dark green, poorly pronounced ribs (21-14), with small circular tubercles, areoles with white wool in young plants; central spines 1-3, 4-20 mm long, straight, subulate to acicular, whitish or light yellow, dark at base and apex; radial spines 14-18 or more, 2-8 mm long, slightly acicular, divergent, white; flower ca. 3 x 4.5-5 cm, yellow (pale golden-yellow; citrus yellow) or pink; elongated fruit with thin walls, ca. 2-3 cm high x 1.8 cm in diameter, dry, with the appearance of white felt, with reddish thorns, black seeds ( Figs. 2 A-D).

The specimens found in this study are in accordance with the above description adapted from Anceschi & Magli (2018) and Carneiro et al. (2016). Although the subspecies P. mueller-melchersii subsp. gutierrezii is no longer a valid name, this name applies for the populations with pink flowers. However, the individuals of the population reported in this study only have yellow flowers.

According to Anceschi & Magli (2018), P. mueller-melchersii differs from Parodia mammulosa (Lem.) N.P. Taylor , the most morphologically similar species, by its higher number of ribs (21-24 vs. 13-21) ( Figs. 3 A-B), by its not-flattened central spines and by its thinner radial spines ( Figs. 3 C-D). According to Carneiro et al. (2016) the flowers of P. mammulosa (1-3.5 x 2-3.5 cm) have a funiliform, densely wooly hypanthium, with bristly thorns which is absent in the flowers of P. mueller-melchersii flowers. Additionally, we observed other differences regarding floral morphology in the populations of the two species found in this study, such as longer, lanceolate, pale golden-yellow tepals; the lobed, red-purple stigma with close lobes pointing upwards (“closed shape”) in P. mueller-melchersii ( Fig. 3E ); while P. mammulosa presented flowers with shorter, tubular lanceolate tepals of bright golden-yellow coloration, lobed red-pink stigma with distant lobes pointing outside (“open shape”) ( Fig. 3F ).

Distribution and habitat: Currently, this species is known to occur in Rio Grande do Sul (BR) and Uruguay ( Fig. 1 ); yet exclusively in the Pampa Biome, where inhabits rocky soils and outcrops at 150-300 m high (Anceschi & Magli 2018). A natural population was found growing in a dry-field area (elevation 60-70 m above the sea level) in the shrub fields phytophysiognomy region in the 3 rd subdistrict of Jaguarão/RS. The place where the population occurs is characterized as a rocky place, composed by volcanic rocks from the Serra Geral Formation, slightly lighter in color compared to basalts strictu sensu, with crystallized quartz and volcanic glass in its composition (Glaucos Ribeiro personal communication); located on the hillside of a small hill (locally known as “coxilha”), surrounded by a vegetation dominated by grasses and bryophytes ( Figs. 4 A-B). Near the same region other species of cacti can be found associated with the same habitat, such as P. mammulosa , Parodia erinacea (Haw.) N. P. Taylor and Frailea gracillima (Lem.) Briton & Rose.

Figures

Fig. 1. Parodia mueller-melchersii distribution map. Previous records (orange); New record of occurrence from this study (red).

Figs. 2A-D. Parodia mueller-melchersii.A. General appearance (frontal view);B. General appearance (lateral view);C. Habitus;D. Juvenile specimens.

Figs. 3A-F. Morphological differences between P. mueller-melchersii and P. mammulosa. A. P. mueller-melchersii ribs; B. P. mammulosa ribs; C. P. mueller-melchersii spines; D. P. mammulosa spines; E. P. mueller-melchersii flower; F. P. mammulosa flower.

Figs. 4A-B. Parodia mueller-melchersii habitat in Jaguarão, RS.A. Rocky outcrop; B. Surrounding vegetation.