Rhombophyllum nelii

[Otter]

Pop name: Elk Horns

IMG_20160124_081316.jpg (68.18 KiB) Viewed 1687 times

IMG_20160124_081541.jpg (79.79 KiB) Viewed 1687 times

[JoeM50]

While I believe the common name of Elk's Horns is correct for these photos, I believe the scientific name of Rhombophyllum nelii synonym Hereroa nelii is a different plant which has a common name of Shriner's Plant. The Book of Cacti and Other Succulents (Claude Chidamian, 1958), which I must have purchased as a teenager sometime about 10 years after the copyright date (possibly as an offer from a book club), lists the two species Hereroa dyeri (Elk's Horns) and Hereroa nelii (Shriner's Plant). Hereroa nelii (Shriner's Plant) is described as resembling the badge used by the Shriner's organization. In the link, <https://www.etsy.com/listing/693687133/ ... s-elkhorns>, there is photo by Valentino Vallicelli which has leaves which are laterally compressed into a broad crescent or hooked shape. Even though this seems to be showing the correct photo for Rhombophyllum nelii, the common name Elk's Horns is being used incorrectly. I believe this is a photo of Rhombophyllum nelii synonym Hereroa nelii. The two names seem to be confused in the nursery trade. The correct name for Elk's Horns seems to be Rhombophyllum dolabriforme or Rhombophyllum dyeri with a synonym of Hereroa dyeri. Wikipedia lists both R. dolabriforme and R. dyeri as valid names and I'm not certain. I am not sure whether these two names apply to the same plant or if R. dolabriforme is a different plant as Wikipedia says. I haven't been able to access the database at The Plant List for several days, but even they sometimes list two "Accepted" names for the same plant especially if they were verified by Tropicos. When I search under "Rhombophyllum for sale", several of the listings (succulentsbox.com, mountaincrestgardens.com, zensability.com) list Rhombophyllum dolabriforme as Elkhorn Plant. Somewhere I saw that R. dyeri was now a synonym of R. dolabriforme but I can't find it again.

[mickthecactus]

Interesting stuff and good pictures. Thanks.

[JoeM50]

I did some further checking under the article
https://en.wikipedia.org/wiki/List_of_A ... uth_Africa
which lists 5 species:
Rhombophyllum albanense (L.Bolus) H.E.K.Hartmann synonym Hereroa albanensis L.Bolus, endemic
Rhombophyllum dolabriforme (L.) Schwantes, endemic
Rhombophyllum dyeri (L.Bolus) H.E.K.Hartmann synonym Hereroa dyeri L.Bolus, endemic
Rhombophyllum nelii Schwantes, endemic
Rhombophyllum rhomboideum (Salm-Dyck) Schwantes, endemic
[Martin Heinrich] Gustav Schwantes [standard author abbreviation Schwantes] is the original author of the Genus Rhombophyllum. He wrote articles and books on botany, horticulture and archaeology until his death in 1960. I can't find the original paper or book in which he proposes this Genus but I suspect it was around 1928 when he named the Genus Carpobrotus (Hottentot Fig).
In <https://en.wikipedia.org/wiki/Rhombophyllum>, there is a color drawing of Rhombophyllum dolabriforme. This drawing looks nothing like the plant known (and pictured here) as Elk's Horns. It has differently shaped leaves and a visible long internode. The only reference listed for this wikipedia article is [Z. Sukkulentenk. 3: 16, 23. 1927.] which may be the paper where the Genus Rhombophyllum is first named. I found confirmation of this article at:
http://colplanta.org/taxon/urn:lsid:ipn ... es:16330-1
This site seems to have links to photocopies of herbarium sheets but only some of them are coming up with my slow phone connection.
I therefore conclude that this photo is Rhombophyllum dyeri and that this is the correct scientific name for the plant known as Elk's Horns in the photographs above.
Doing an image search for Rhombophyllum nelii brought up lots of photos which appear to be Elk's Horns but these two match the name Shriner's Plant and I believe that these are correctly identified.
https://www.etsy.com/listing/693687133/ ... la=1&gao=1&
http://llifle.info/Encyclopedia/Plant/F ... llum_nelii
Some plants appear to be hybrids between the two species, having laterally flattened, crescent shaped leaves but with a forked tip. One other is completely different and may be Rhombophyllum dolabriforme or one of the other species.