Dypsis decaryi

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Triangle Palm

Dypsis (DIP-sis)
decaryi (deh-KAHR-ee)
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Montgomery Botanical Centre, Florida. Photo by Dr. William J. Baker, Royal Botanic Gardens, Kew/Palmweb.
Scientific Classification
Genus: Dypsis (DIP-sis)
Species:
decaryi (deh-KAHR-ee)
Synonyms
None set.
Native Continent
Africa
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Morphology
Habit: Solitary
Leaf type: Pinnate
Culture
Survivability index
Common names
Triangle Palm

Habitat and Distribution

Endemic to South Madagascar, confined to a small area. Dry forest or bush on stony soil,
Australia.
mid slope; alt. 80-600 m.

Description

Solitary palm. TRUNK (0.5-) 3-6 (-10) m high, 30-40 cm in diam.; internodes 3-10 cm, grey. LEAVES tristichous, 18-24, 1.5-3.25 m, porrect, arched, twisted around the rachis, marcescent; sheath open, 30-45 cm long, 40-65 cm wide when flattened, yellow-green with dense white wax usually overlaid by thick reddish pubescence, with ligules 7 cm high, 10 cm wide, orange turning grey-brown; petiole 33-50 cm long, proximally 6-7.5 x 9-10 cm in diam., distally 5 x 5 cm, channelled with sharp margins, abaxially with reddish pubescence but glabrescent; rachis 2.2-3 m long, densely pubescent but glabrescent, channelled proximally, in mid-leaf 2-3 x 1.3-2.3 cm and keeled; leaflets 55-97 on each side of the rachis, regular, glaucous, at an angle of 90° with the leaflets on the opposite side of the rachis, the proximal 80-140 x 0.5-1 cm, (the most proximal often with reins and pendulous), median 58-89 x 2-3.5 cm (interval 2-5 cm), distal 10-60 x 0.4-1.6 cm, the top pair not or hardly connate, one or two tuft(s) of long brown-red ramenta present on the proximal part of erect, hooded, split for 90% with only the proximal part closed, with scattered scales; peduncular bract inserted at 18-20 cm from the base of the peduncle, 40-55 cm long, open over most of its length but closed and beaked for the distal 5-19 cm, with scattered scales; rachis about 118 cm, with all axes flaking and densely scaly, with 20-26 branched and about 18 unbranched first order branches, these proximally flattened, their base up to 7 x 5 mm; most proximal first order branches with their rachis up to 50 cm long and up to 22 second order branches (8 of these branched again); rachillae pale yellow-green, 12-26 cm long, 1-4 mm in diam.; triads, distant, slightly sunken, with small yellowish flowers. STAMINATE FLOWERS with sepals 1.7-2.1 x 1.6-2 mm, concave, keeled and proximally gibbous, elliptic, rounded, entire; petals on a 1.2-1.5 mm high receptacle, 3.2- 3.5 x 1.8-2.3 mm, elliptic, fleshy, acute; stamens 6, very slightly biseriate, with the antepetalous stamens inserted slightly higher than the antesepalous ones, filaments 2.4-3 mm the abaxial midrib, and lines of scattered minute reddish scales present on the fainter veins, main vein 1, very prominent adaxially, as well as thickened margins, apex unequal, bifid in median leaflets. INFLORESCENCE interfoliar, 125-178 x 120 cm, widely spreading, branched to 3 orders; peduncle 50-58 cm long, with scattered scales, proximally about 5 x 3 cm in diam., distally about 3.5 x 2 cm in diam.; prophyll 25-63 cm long, borne at 8-12 cm above the base of the peduncle, long, thin, anthers 1.7-2 x 1 mm, dorsifixed, versatile, held horizontally at anthesis, the locules parallel and obtuse; pistillode cylindrical, about 1.6 mm high and 1 mm in diam. PISTILLATE FLOWERS unknown, but from fruiting material sepals 2.4-2.8 x 2.6-3.3 mm, broadly ovate with a small apiculum; petals c. 3.3 x 4.3 mm, with broad membranous wings and a small fleshy triangular apex; staminodes c. 1 mm high. FRUIT ovoid, later subglobose, 15-22 x 12-19 mm, with rounded apex; mesocarp fleshy-fibrous, endocarp fibrouswith anastomosing fibres. SEED subglobose to ellipsoid, 17-19 x 15-17 mm, slightly asymmetric with an apiculate base (1 mm), with shallow anastomosing grooves over its surface, with rounded apex, and an equatorial depression corresponding to the embryo; endosperm ruminate, with ruminations up to 6 mm deep. (J. Dransfield and H. Beentje. 1995)/Palmweb. Editing by edric.

Quite similar to D. madagascariensis but altogether neater in appearance, with its more compact habit and the densely three-ranked leaves. (J. Dransfield and H. Beentje. 1995)/Palmweb.

Culture

IN SOUTHERN CALIFORNIA, and similar climes: D. decaryi appear to appreciate both regular moisture AND fast drainage. They like full sun, and hate clay that drains badly if they are watered too frequently. D. decaryi is extremely drought tolerant and will grow in Southern California with no supplimental irrigation (approx 9" of rain annualy). In these non irrigated plantings, the palms actually benefit from a heavier soil. Cold Hardiness Zone: 10a

In Hawaii and other wetter locations, a catastrophic phenomena has been observed on mature trees with the crown completely snapping off. This malady is discussed in the Palmpedia Slide Show - PALM DISEASES AND PESTS IN HAWAII It is theorized that excessive moisture can collect in the "Triangle's" crown and become heavy enough to cause the fatal snap.

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Comments and Curiosities

The famous 'Triangle Palm' is widespread in cultivation, and is grown in a wide variety of climates; this is unlike its native status, where it is restricted to a very narrow habitat 'niche', and as a result has a very restricted distribution. The name refers to the collector of the type, Raymond Decary. (J. Dransfield and H. Beentje. 1995)/Palmweb.

D. decaryi is the well-known Triangle Palm, a name that reflects the three-ranked (tristichous) pattern of leaf attachment to the trunk. It matures to 10 to 20 ft. in height, with a trunk diameter of roughly 12 to 16 in. Leaves and leaflets are strongly arched. The fruit of D. decaryi is attention-getting – almost round, about .7 in. in diameter, and coated with a white wax. Though this species grows in rocky soil in habitat, it produces a stouter trunk in southern Florida when planted in sand, rather than in limestone. A sun-lover, it nevertheless can adapt to the lower-light conditions of indoor culture. Ironically, while widespread in cultivation, it occurs endemically in a very confined area of dry forest or bush, so its IUCN Red List conservation status is Vulnerable, with a decreasing population trend. (fairchildgarden.org)

Conservation: Vulnerable. Only known from a small area, where nearly all seed is harvested for export; fires are a threat. Population estimated at a thousand. This species is listed on CITES Annexe II. (J. Dransfield and H. Beentje. 1995)/Palmweb.

Uses: Leaf used for thatching; fruits eaten by children, and formerly used to prepare a fermented drink; seeds exported for horticultural use, as the species is a prized ornamental.

NATURAL HISTORY: J. Ratsirarson (pers. comm.) has observed both Black Parrot and Lemur catta feeding on the fruit mesocarp; he also found pig droppings full of seed of D. decaryi; he observed bees and flies visiting the flowers at anthesis. (J. Dransfield and H. Beentje. 1995)/Palmweb.

Ease of culture (under the right conditions) has made this species one of the most widely cultivated palms in the world, though nowhere near as ubiquitous as its relative D. lutescens.

Triangle palms grace pots and gardens all over the world, from Southern California, to the south of France, to Australia, Chile and New Zealand, among many other places.


External Links

References

Phonetic spelling of Latin names by edric.

Special thanks to Geoff Stein, (Palmbob) for his hundreds of photos.

Special thanks to Palmweb.org, Dr. John Dransfield, Dr. Bill Baker & team, for their volumes of information and photos.

Glossary of Palm Terms; Based on the glossary in Dransfield, J., N.W. Uhl, C.B. Asmussen-Lange, W.J. Baker, M.M. Harley & C.E. Lewis. 2008. Genera Palmarum - Evolution and Classification of the Palms. Royal Botanic Gardens, Kew. All images copyright of the artists and photographers (see images for credits).

Dransfield, J. & Beentje, H. 1995. The Palms of Madagascar. Royal Botanic Gardens, Kew and The International Palm Society.
Many Special Thanks to Ed Vaile for his long hours of tireless editing and numerous contributions.

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