The Essence
Sihara palmMini-majestyAnivo
"Ravenea glauca is a slender, solitary, dioecious feather palm endemic to Madagascar. RBGE reports that it grows wild in only two national parks, Andringitra and Isalo. It is a variable species: plants can be tall and slender in the canyons at Isalo, but can also flower when almost stemless in a dry river bed. The plant grown in gardens for decades is the Isalo canyon form, sold as R. glauca 'Isalo'; RarePalmSeeds notes it looks very different from the Andringitra plants on which the 1913 description was based, and that page states the Andringitra plant is not yet in cultivation (though the same nursery now also lists an 'Andringitra' form separately). Dransfield and Beentje likewise observed that the protologue describes Andringitra populations while all collections they had seen were of a later date, and that the habit sketch in the Flore de Madagascar (1945) was based on a photograph (Humbert 13698) that is actually R. xerophila. Some growers call it Mini-Majesty, assuming a smaller Ravenea rivularis, but Palmpedia points out the two have little in common: R. glauca is far more delicate and slimmer-trunked, and lacks rivularis's affinity for water. It is not eaten, since the heart is bitter. Palmpedia calls it one of the most promising palms for cultivation Madagascar has to offer, and remarkably bug and pathogen resistant."
EtymologyThe epithet glauca is Latin for bluish-grey. Dransfield and Beentje state that the name refers to the glaucous, waxy undersides of the leaflets; growers also associate it with the glaucous blue appearance of new growth, which plants sometimes retain when grown in a hot, dry location.
Historical ContextDescribed in 1913 by Henri Jumelle and Henri Perrier de la Bathie (Ann. Mus. Colon. Marseille, ser. 3, 1: 56). Dransfield and Beentje's conservation note records uncertainty about the status of the Andringitra populations, with no plants collected there since 1922; elsewhere the species was known only from the Isalo, where they put the population size at probably a few hundred. RBGE gives a figure of an estimated 800 trees left in natural habitat and warns that people harvesting wild seed for the international horticultural trade put pressure on the ability of wild populations to regenerate, an added risk in a species whose plants are either male or female.
Dry forest, ravines and rocky or sandy gullies at 670-1250 m, possibly to about 1800 m, in a climate POWO classes as seasonally dry tropical. At Isalo the plants grow on the lower cliffs of a few moist sandstone canyons in an otherwise rather dry region; in the Andringitra they occupy high mountain savanna and dry forest habitat between granite rocks. The 1913 protologue reported that the species forms vast forests in the Andringitra mountains between 1200 and 1800 m, to the exclusion of any other plant, and said to be resistant to bush fires, though Beentje remarked that, having seen the stands in the Isalo, he found monospecific forests without undergrowth hard to believe.
Origin ZoneMadagascar
Taxonomic FamilyArecaceae
GPS AnchorLatitude-22.052465°
Longitude46.770380°
ReferenceMadagascar Botanical Zone
Technical ProfileHardinessZone 10
Max HeightMedium
Growth RateModerate
GBIF TAXONOMIC KEY2739035
Specimen Gallery Under Curation
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