Rhodocactus nemorosus is a species of flowering plant in the cactus family Cactaceae, native to southern Brazil, Paraguay, Uruguay and northeast Argentina.[1] Like all species in the genus Rhodocactus and unlike most cacti, it has persistent leaves. It was first described by Nicolás Rojas Acosta in 1897 as Pereskia nemorosa, and transferred to Rhodocactus in 2016.[2]

Rhodocactus nemorosus
In cultivation in the Phipps Conservatory and Botanical Gardens, Pittsburgh
Scientific classification Edit this classification
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Eudicots
Order: Caryophyllales
Family: Cactaceae
Genus: Rhodocactus
Species:
R. nemorosus
Binomial name
Rhodocactus nemorosus
(Rojas Acosta) I.Asai & K.Miyata[1]
Synonyms[1]
  • Pereskia amapola F.A.C.Weber
  • Pereskia argentina F.A.C.Weber
  • Pereskia nemorosa Rojas Acosta

Description edit

Rhodocactus nemorosus grows as a small tree or a shrub, reaching 3–5 m (10–16 ft) high, with trunks to 10 cm (4 in) in diameter.[3] Mature stems develop bark and, unlike other species of Rhodocactus, do not have stomata.[4] Like all species of Rhodocactus and unlike most other cacti, R. nemorosus has persistent leaves, the largest being up to 14 cm (5.5 in) long and 6 cm (2.4 in) wide. The leaves are succulent and have short petioles, only 5 mm (0.2 in) long, and are borne on the areoles along with spines. The areoles on the twigs have up to five spines, those on the trunks up to 20 or more, each 4–6 cm (1.6–2.4 in) long. The white to pale pink flowers are either solitary or borne in small terminal inflorescences of two to five, and are 4–7 cm (1.6–2.8 in) across. The fruits are pear-shaped, green or yellowish-green when ripe.[3]

Taxonomy edit

The species was first described by Nicolás Rojas Acosta in 1897 as Pereskia nemorosa.[2] Molecular phylogenetic studies suggested that when broadly circumscribed, Pereskia was not monophyletic, and consisted of three clades.[5][4] In 2016, the genus Rhodocactus was revived for one of these clades, which included R. nemorosus.[4]

Distribution and habitat edit

Rhodocactus nemorosus is native to southern Brazil, Paraguay, Uruguay and northeast Argentina.[1] It is found in drier wooded habitats.[3]

References edit

  1. ^ a b c d "Rhodocactus nemorosus (Rojas Acosta) I.Asai & K.Miyata", Plants of the World Online, Royal Botanic Gardens, Kew, retrieved 2021-05-01
  2. ^ a b "Rhodocactus nemorosus (Rojas Acosta) I.Asai & K.Miyata", The International Plant Names Index, retrieved 2021-05-01
  3. ^ a b c Anderson, Edward F. (2001), "Pereskia nemorosa", The Cactus Family, Pentland, Oregon: Timber Press, p. 570, ISBN 978-0-88192-498-5
  4. ^ a b c Asai, Issaku & Miyata, Kazunori (2016), "An Emendation of Rhodocactus, a Genus Segregated from Pereskia (Cactaceae)" (PDF), Journal of Japanese Botany, 91: 7–12, retrieved 2021-04-25
  5. ^ Bárcenas, Rolando T.; Yesson, Chris & Hawkins, Julie A. (2011), "Molecular systematics of the Cactaceae", Cladistics, 27 (5): 470–489, doi:10.1111/j.1096-0031.2011.00350.x, S2CID 83525136