Rhipsalis grandiflora discussion (Ken Friedman 1980)
Left, R. grandiflora. Right, R. hadrosoma
Commercial R. grandiflora Haworth (Lepismium grandiflorum) is a pencil type with small cream to white flowers along the stems growing from areoles typical of Lepismium. The tiny areoles are often colored red so the stems look like they are covered with spots. Fruit is red.
R. hadrosoma Lindberg and L. grandiflorum Haworth are part of yet another mystery. Graf showed two photographs in his Exotica (1973 ed.), one purported to be a fruiting R. hadrosoma and the other, a flowering R. grandiflora. The photographic references appear similar, though black and white photographs do not build confidence for identification. Indeed, Graf's written description noted that R. hadrosoma was a "much branched bush similar to grandiflora but the forking, cylindrical, reddish branches are thicker...(p. 1703)." Rose recognized R. grandiflora, but rejected R. hadrosoma despite Lofgren's drawing and description that depicted the two species as distinct.
The fruit and flower descriptions of the two species did not help solve the dilemma either. Rose did not see R. grandiflora first-hand, relying instead on a photograph and description sent to him by someone else. The description he received was of a plant with cream flowers showing some rose coloration. Rose copied the description of the fruit as purplish. But Graf's R. hadrosoma had pale pink fruit and he failed to cite a fruit color for his R. grandiflora. Borg was of little help; he recognized both species and his flower references failed to mention rose coloration at all.
The opportunity to examine both R. hadrosoma and Lepismium grandiflorum (the latter having been reclassified in the Lepismium genus following earlier writings) would undoubtedly clear up this identity mystery. Innes (1977) felt the two were separate species.
The Lepismium group is noticeably different from Rhipsalis in flower characteristics and in the typical Lepismium fruit-bearing areole that tends to be sunken in the stem and filled with wooly hairs or fuzz.
R. grandiflora is available commercially in the U.S. but R. hadrosoma is generally unavailable commercially and therefore could be questioned.
Barthlott (1977b) indicated that R. hadrosoma is synonymous with R. grandiflora, the former being well-described and cultivated verifiable specimens. He felt that R. grandiflora, on the other hand, was not verifiable and thus once again we have a situation where existing species named R. grandiflora (or L. grandiflorum) should be compared with existing species named R. hadrosoma so one or the other can be eliminated. If Barthlott is correct, then what passes for R. grandiflora could be renamed R. hadrosoma or vice versa.
The New Cactus Lexicon by David Hunt (2007) lists R. grandiflora and refers R. hadrosoma to it.