Acanthophoenix rousselii
illustration: Rub / Wikipedia
illustration: Rub / Wikipedia
Roussel Palm [W]
Acanthophoenix is a monoecious genus of flowering plant in the palm family from the Mascarene Islands in the Indian Ocean, where they are commonly called palmiste rouge. A genus long in flux, three species are currently recognized, though unsustainable levels of harvesting for their edible palm hearts have brought them all to near extinction in habitat. They are closely related to the Tectiphiala and Deckenia genera, differing in the shape of the staminate flower. The name combines the Greek words for "thorn" and "date palm".
Solitary pleonanthic monoecious palm with erect trunk to 15–25 m tall and 20–30 cm diam., surface light gray, rather smooth, only slightly marked with leaf scars; trunk base swollen in a characteristic “elephant foot.” Leaves pinnate, 15–20 in crown; crownshaft conspicuous, , sheaths 90–120 cm long, 45 cm wide at the base, up to 6 mm thick, abaxially dark brown, covered with dense furlike black hair 6–8 mm long, except on half length median axis where glabrous; petiole and rachis 2.50–3 m long, glabrous or with a fine indument abaxially in the distal part; leaflets 70–80 pairs, pendulous and regularly attached on both edges of the rachis, leaflet tip acute, olive green color on both surface, leaflet midrib adaxially armed with thin reddishbrown bristles 2–4 cm long, thin flexuous dotlike scales on abaxial side of midrib. Inflorescences infrafoliar, first enclosed in a tough unarmed brown prophyll; inflorescences ivory-colored, pendulous, 100–110 cm long, branching to 2 orders with 50–70 rachillae; peduncle base enlarged in a crescent shape where attached to the trunk; peduncle and rachis armed with strong sinuous black spines 2–3 cm long; rachillae bearing densely arranged triads of flowers, two staminate flowers flanking one pistillate flower, all sessile and glabrous. Staminate flowers 12 × 12 mm, ivory white turning to light yellow except pistillode and basal part of filaments pinkcolored; sepals 3, narrow triangular with acute tip, 1.5 mm long; petals 3, elliptic, valvate, 7 × 3 mm; stamens 9 (sometimes 8) with white sagittate anthers 3–4 mm long and coiled filaments 8 mm long; pistillode 2–3 mm with trifid tip. Pistillate flowers ivory-white, globose to subspherical, slightly asymetrical, smaller than staminate flowers 4.5 × 3–4 mm; sepals and petals similar, membranous, imbricate. Mature fruit black with persistent beige or light brown perianth, ellipsoidal and slightly curved, 15–20 × 8 mm; mesocarp thin, dark purple; endosperm homogenous, embryo basal. [3]
a A. rubra staminibus plerumque 9 vice 11 vel plus, fructu curvato vice ellipsoideo differt, a A. crinita staminibus 9 vice 6, fructu multo majore et eophyllo pinnato vice bifido differt.
GENUS [A]Acanthophoenix
SUB-FAMILY [N]Arecoideae
TRIBE [N]Areceae
SUB-TRIBE [N]Oncospermatinae
PUBLICATION [A]
BIOLOGY [C][3]
See protologue pdf.
Distribution [C][3]
Réunion
USES [W]
SYNONYMS [C]
CULTIVATION
Cold Hardiness Zone (USDA) 10a
GROWTH RATE
MINIMUM TEMPERATURE
exposure
MAX HEIGHT
BIBLIOGRAPHY & SOURCES
[3] N. Ludwig, Acanthophoenix in Réunion, Mascarene Islands. 2006
[3] Govaerts, R.H.A. (2011). World checklist of selected plant families published update. Facilitated by the Trustees of the Royal Botanic Gardens, Kew.
[A] Palmweb - Palms of the World Online - http://www.palmweb.org
[C] WCSP 2013. World Checklist of Selected Plant Families. Facilitated by the Royal Botanic Gardens, Kew. Published on the Internet; http://apps.kew.org/wcsp/ Retrieved 2011 onwards
[N] The National Center for Biotechnology Information (NCBI) - http://www.ncbi.nlm.nih.gov
[W] Wikipedia: http://en.wikipedia.org/wiki/Acanthophoenix
eMonocot: http://e-monocot.org/taxon/urn:kew.org:wcs:taxon:345632
The World Checklist of Monocotyledons: http://apps.kew.org/wcsp/home.do
The National Center for Biotechnology Information (NCBI): http://www.ncbi.nlm.nih.gov/
IUCN Red List: http://discover.iucnredlist.org
