Archontophoenix alexandrae (F.Muell.) H.Wendl. & Drude

Alexandra palm (en)

Species

Angiosperms > Arecales > Arecaceae > Archontophoenix

Characteristics

A tall slender palm. It has a single stem and feather like leaves. These fronds arch over and the drooping leaflets are silvery grey underneath. The trunk is grey and can be 30 m tall. It is 25 cm across. The trunk is swollen at the base and has rings of leaf scars on it. The leaves are 2-3 m long and 60-90 cm wide. The leaf stalk is smooth and has a sheathing base forming a 1 m long crown-shaft. The leaflets are 30-45 cm long and 2-5 cm wide. They are evenly and closely spaces and point forward. The central vein is yellow and raised on the upper surface. The flowering stalk is large and branched. The small branches hang downwards carrying flowers. The flowering stalk can be 40-80 cm long. It is immediately below the crown-shaft and it is yellow. The 2 large pale green pointed leaf-like bracts fall before the flowers open. The flowers have male and female flowers on the same stalk. They are cream and about 8 mm across. Fruit are green but turn red when ripe. They are oval and 10-15 mm long. They have a smooth waxy surface. They contain a single fibrous seed with a fleshy layer around it.
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Trunk to 30 m tall, to 30 cm diam. Leaves 10–12, to 4.5 m long, becoming vertically orientated; leaf sheath mid to lime green. Pinnae 60–80 each side of rachis, to 75 cm long, dark green adaxially, silver-grey abaxially; ramenta lacking. Inflorescence to 100 cm long, branched to 4 orders; axes white to creamy green; rachillae to 30 cm long, erect to semipendulous, moderately flexuose distally. Flowers widely spaced on rachilla; floral bracts raised with sharp margins; perianth white to cream. Staminate flower to 9.5 mm long; stamens 9–16; filaments curved; pistillode about equal to petals. Pistillate flower to 4 mm high. Fruit ovoid, 8–14 mm long, 6–11 mm wide; stigmatic remains apical; mesocarp fibres to 1 mm wide, flat, sparingly branched, remaining compact in the dried state. Seed globose, 8 mm diam.; raphe fibres weakly adherent.
Life form perennial
Growth form tree
Growth support free-standing
Foliage retention evergreen
Sexuality -
Pollination -
Spread -
Mature width (meter) 2.5
Mature height (meter) 30.0
Root system -
Rooting depth (meter) -
Root diameter (meter) -
Flower color
Blooming months
JanFebMar
AprMayJun
JulAugSep
OctNovDec
Fruit color
Fruiting months
JanFebMar
AprMayJun
JulAugSep
OctNovDec
Nitrogen fixer -
Photosynthetic pathway c3

Environment

It is a tropical and subtropical plant. It occurs in rainforests often along stream banks. It suits humid locations. In northern Australia is grows from sea level to 1200 m altitude. They need well-drained soils. They cannot stand frost. It is damaged by drought. It suits lightly shaded positions. It suits hardiness zones 10-12. In the Cairns Botanical Gardens.
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Grows on various soil types in rainforest, swampforest and moist sclerophyllforest at 0–1000 m alt. 
Light 4-6
Soil humidity 4-7
Soil texture 3-4
Soil acidity 2-8
Soil nutriment -
Hardiness (USDA) 10-12

Usage

The young bud or cabbage can be eaten raw. As this would kill the palm it is not normally done. The fruit can be cooked and eaten. They need processing.
Uses environmental use medicinal
Edible fruits
Therapeutic use -
Human toxicity -
Animal toxicity -

Cultivation

Plants are grown from fresh seed. They germinate in 3 months. Seedlings transplant easily. Seed germination is increased by soaking in water for 24-72 hours. It is also further improved by treating for 72 hours with 100 or 1000 ppm of gibberellic acid.
Mode seedlings
Germination duration (days) -
Germination temperacture (C°) -
Germination luminosity -
Germination treatment -
Minimum temperature (C°) 1
Optimum temperature (C°) -
Size -
Vigor -
Productivity -

Images

Archontophoenix alexandrae unspecified picture

Distribution

Archontophoenix alexandrae world distribution map, present in Australia, Brazil, and United States of America

Conservation status

Archontophoenix alexandrae threat status: Least Concern

Identifiers

LSID urn:lsid:ipni.org:names:664083-1
WFO ID wfo-0000260904
COL ID G9YC
BDTFX ID -
INPN ID 629096
Wikipedia (EN) Link
Wikipedia (FR) Link

Synonyms

Archontophoenix alexandrae Saguaster drudei Jessenia glazioviana Ptychosperma alexandrae Archontophoenix beatriceae Seaforthia alexandriae Archontophoenix alexandrae var. schizanthera Archontophoenix alexandrae var. beatriceae Ptychosperma beatriceae Ptychosperma drudei