Invasive Species Compendium

Detailed coverage of invasive species threatening livelihoods and the environment worldwide

Abstract

A dwarf species of ravenea, well known for some time in cultivation, is described and named for the first time.

Abstract

This striking species of Ravenea first came to my notice in the 19905 when Rolf Kyburz, a nurseryman from Queensland, sent me pictures of a squat palm looking just like a cycad, growing on a steep slope above Mahatalaky, just north of Toalagnoro (Fort Dauphin) in the far south of Madagascar. Although the habit photographs were out of focus, they did at least give a good impression of the palm. A close-up of a staminate inflorescence confirmed the generic identi- fication as Ravenea. The dwarf habit suggested Ravenea nana (Beentje 1994), but R. nana is a much less squat, more slender palm lacking the striking cycad-like appearance (at least as shown by herbarium specimens). Subsequently, photographs (Figs. 1 8t 2) of what appears to be the same palm arrived from Toby Spanner, RarePalmSeeds.com, in Ger- many. Taken by a local collector working for the seed exporter Gunther Gottlieb, the photo of habit suggested his palm to be exactly the same species. A close-up of the crown showed an infructescence with unusually large fruits. This palm entered the trade as Ravenea "cycadifolia." Individuals are now beginning to flower and fruit in Hawaii (Figs. 3 8t 4) and in La RĂ©union (Figs. 5-7) (and probably elsewhere), and it is now opportune to describe and name the palm. The very distinctive habit with short squat stems, the crown with an unusually large number of leaves and the fruit size that seems out of proportion to the rest of the plant, make this species highly distinctive (and desirable). Recently, I have become aware of further undescribed species of Ravenea from the Fort Dauphin area, from photographs sent by Olivier Reilhes, which together with the unusual Ravenea declivium described by Mijoro Rakotoarinivo and myself from Tsitongam- barika just a little north of Mahatalaky suggest that this southeast corner of Madagascar is a hotspot for Ravenea and deserves much Closer exploration. In Palms of Madagascar (Dransfield & Beentje 1996) the new palm would probably key out, based on habit, to the poorly known Ravenea Hana, but R. nana has a short slender stem, many fewer leaves in the crown and smaller fruit. The material of Ravenea cycadifolia on which this description is based was obtained from Floribunda Palms and Exotics, Mountain View, Hawai'i.