L. rigidum (Loefgren.) Backeberg.
Possibly linked to R. neves-armondii by Britton and Rose
Info from Backebergs Lexicon 1977
Translation into English of Rhipsalis rigida sp. n. Loefgren in Archivos do Jardim Botanico de Rio de Janeiro, Vol. I, Fasc. I, 1915, pp. 93 - 94. Original language: Latin diagnosis and Portuguese description. Translated by Peter Krebs, 12/2003.
Rhipsalis rigida sp. n. Loefgren.
Frutex erectus vel suberectus, rigidus, basi lignescentibus, subcylindricus, dein angulosus, sparce ramosus; ramis vel articulis solitariis et turiones fusiformibus; areolis spiraliter dispositis et proximatis; squamulis rubris, triangularis vel lanceolatis, albo-setosis, parce lanosis; floribus stramineis, lateralis; bacca disciforme, immersa, probabiliter rubra.
This species is almost shrubby, erect or almost so, with a woody base and a grey bark; the main stem is upright, almost cylindrical, up to 16 mm. thick, clearly 5-angled and only slightly branched. The branches are arranged irregularly, never verticillate nor even in twos, obtusely 5-angular, up to 60 cm. long and 8 - 15 mm. thick, dark green. The uppermost segments (the youngest shoots) are fusiform with the areoles closely set and spirally arranged, furnished with red, triangular to lanceolate scales and with 5 - 15 white almost stiff bristles and with some slight woolliness.
The flowers are lateral, almost rotate, with 12 - 15 perigonal-leaves, all of which are straw-yellow, the outer ones smaller, with a central nerve and a red apex, obtusely oblong, almost hooded, up to 12 mm. long. The stamens and the anthers likewise are straw-yellow, as are the stylus and the 4 - 5 spreading stigma lobes. The ovary is entirely sunken in the branch; the fruit is more or less disc shaped. We have not seen it in the ripe state.
This species differs from all the others by the extraordinary rigidity and length of the secondary stems and by the deep colour of its flowers. The similarity of the young shoots with those of Rh. dissimilis is astonishing, but the adult types are entirely different.
It was collected by Dr. Arthur Löfgren at the Cachoeirinha (Great Waterfall) of Serra da Cantareira in S. Paulo. It grows on rocks, but is also epiphytic. It has been cultivated at the Sao Paulo Botanical Gardens. Unfortunately we have lost the drawings of this species.