Ammandra decasperma

Ammandra (aham-MAHN-drah) decasperma (deh-kahs-PEHR-mah)
Yasuni National Park, Orellana, Ecuador. Pistillate Inflorescence (Left) and Pistillate Flower in 2 Views. Photo by Dr. John Dransfield, Royal Botanic Gardens, Kew/Palmweb.
Scientific Classification
Genus: Ammandra (aham-MAHN-drah) Species: decasperma (deh-kahs-PEHR-mah)
Synonyms
None set.
Native Continent
America
Morphology
Habit: Solitary & clustering. Leaf type: Pinnate
Culture
Survivability index
Common names
None.

Habitat and Distribution

Colombia.

Yasuni National Park, Orellana, Ecuador. Photo by Dr. John Dransfield, Royal Botanic Gardens, Kew/Palmweb.

Description

Ammandra decasperma grows in multi-headed clusters, the trunks usually remaining underground or prostrate upon it. Despite the negligible trunk size, the leaves reach over 6 m long, slightly arching, on 2 m petioles. The linear leaflets are dark green, 60–90 cm long, and emerge from the rachis in the same plane. In male plants the inflorescence is a long spike covered in short branches of white to yellow flowers, the female's being much shorter and more compact. The round fruit grows in clusters of 3-6 and is covered in pointed warts, each fruit containing six or more kidney shaped seeds.

The type species described by Cook was Ammandra decasperma; a similar population was found being geographically separated and with minor flower differences and was designated A. dasyneura (Burret). In September 2001 Bernal et al. published the discovery of an Ammandra population located between the other two with floral characteristics represented in both groups. They, and other taxonomists since, concluded that the three populations were of a single species (see distribution map). Separately, the only species in the closely related Aphandra genus, Aphandra natalia, was initially described as Ammandra natalia but was later given its own genus.

Solitary or clustered dioecious palm, with stems short and subterranean, or prostrate, and up to 1.5 m long and 25-35 cm in diameter, usually decaying at the older portions. Leaves 8-20 erect or arching; sheath l-1.7 m long, strongly fibrous, most of it appearing like the petiole; petiole cylindrical, l-2.4 m long, 2-2.5 cm in diameter, green; rachis 3.3-4 m long, with 40-62 pinnae; middle pinnae opposite, to 85 cm long and 5 cm wide, glabrous, with a prominent submarginal vein on either side of the midvein. Inflorescences interfoliar, the staminate up to 1.4 m long; peduncle 30-75 cm; peduncular bract 35-50 cm long; rachis 3O-92 cm long; rachillae 45-90, each with 6-9 flowers 0.5-3 cm long, the proximal ones larger and with more stamens; perianth obscure, hidden by the enlarged receptacle, the latter making the most conspicuous part of the flower; receptacle prismatic, to 1.5 cm long, with a small, central pistillode; stamens 300-1321; filaments 0.1-0.9 mm long; anthers 0.5-1.7 mm long. Pistillate inflorescence with peduncle to 30 cm long; peduncular bt'act 15*30 cm long; pistillate flowers 6-10 densely arranged in a head on a short rachis 1-2.5 cm long, each flower up to 25 cm long, with 7-10 narrow tepals to 10 cm long; ovary with 6-10 locules; style to 7 cm long; stigmas to 5 cm long. Infructescence 2O-25 cm diameter, with 3-10 fruits. Fruit depressed-globose1, 0 -12 cm diameter, with woody spiny projections to L cm long; seeds 6-10, wedge-shaped, with two flat sides, the distal surface convex, 4.5-5 cm long, 3-4 cm wide,2.2-3 cm along the tangential face. (R. Bernal, Notes on the Genus Ammandra (Palmae). 2001)/Palmweb. Editing by edric.

According to Barfod, Ammandra dasyneura differs from A. decasperma mainly in the larger number of stamens (800-1200 vs. 300-500), with longer filaments (0.5 vs. 0.1-0.2 mm) and longer anthers (1-1.7 vs. 0.5 mm). These differences, faint as they might seem, were reinforced by the isolation of both species on either side of the Andes. Ammandra decasperma was known only from the Pacific lowlands of Colombia, west of the Andes, whereas A. dasyneura was known from the northwestern Amazon in Colombia and Ecuador, east of the Andes. No populations of this genus had been found in the inter-Andean valleys in between. During recent field work in central Colombia, we found a population of Ammandra in the wet middle valley of the Magdalena river. As this valley lies deep between the Central and Eastern Andean cordilleras, in an area intermediate between the ranges of A. dasyneura and A. decasperma, the finding was particularly interesting. Thus, we have reassessed the differences between the two species, under the light of the new discovery. (Dr. Rodrigo Bernal)

Culture

Ammandra is not common in cultivation outside its natural range but when grown requires wet and warm conditions resembling the rain forest and will not tolerate full sun when young. It also prefers free-draining, highly organic soil. Cold Hardiness Zone: 10a

Comments and Curiosities

Etymology: The genus name translates from Greek to "sand man", because "The stamens are minute and have the appearance of small grains of sand scattered over the surface of the receptacles", and the species epithet derives from two Latin words meaning "ten" and "seed", describing the maximum number of seeds per fruit.

Uses: The weaved pinnae of the leaves are used for thatch. the large white seeds, commonly called "vegetable ivory", are carved into buttons and trinkets. Leaves are used to make temporary baskets. Fibres from the leaf base of juvenile plants are used to make brooms. The mesocarp, preferably mature, is edible. The endosperm is also edible when immature in a liquid or jelly-like state. The endosperm is eaten to cure diarrhea and stomach ache. (Macía, M.J., Multiplicity in palm uses by the Huaorani of Amazonian Ecuador. 2004 (as Ammandra dasyneura (Burret) Barfod)