Archontophoenix - Research@JCU

Archontophoenix (Arecaceae)
Description of Species and Notes
Article and photos by John Leslie Dowe
Australian Center for Tropical Freshwater Research
James Cook University.
Townsville, QLD Australia
[email protected]
O
f the nine endemic genera of palms that occur in Australia,
Archontophoenix is the most diverse with six species. The genus is
mainly confined to high rainfall areas, most often in well-developed
rainforest, and is intolerant of fire or extended drought. Although
predominantly tropical, one species extends to warm temperate
Australia. Some of the tropical species occur at relatively high
altitudes, in cool wet conditions, and may represent evidence of
relictual distribution patterns. Fossil evidence suggests
that Arecoid palms were once widespread across
southern Australia, but whether they can be directly
related to extant genera such as Archontophoenix
cannot be verified at present.
The morphological variation within
Archontophoenix is relative narrow, and species are
primarily delimited by the following characters:
- leaflets with the presence/absence of dense silvergrey tomentum, and ramenta on the abaxial surface
- stamen number
- fruit size and colour
- condition of the fibres in the mesocarp
- colouration and morphology of the crownshaft
The following treatment is based on
extensive field-work and herbarium research
conducted by the author, and is largely taken from
the forthcoming treatment of the palm family in the
Flora of Australia series and the ‘Systematics of the
Australian Palm Flora’ project.
Taxonomy and species descriptions
Archontophoenix H.Wendl. & Drude, Linnaea 39: 182, 211
(1875); from the Greek archon (king or ruler), and phoenix
(palm).
Loroma O.F.Cook, J. Wash. Acad. Sci. 5: 117 (1915).
Solitary, erect palms. Trunk slender,
frequently with swollen base. Leaves paripinnate,
caducous; rachis ±straight or curved; leafsheath
forming a tubular crownshaft. Leaflets reduplicate,
linear-acute, in a single plane; midrib prominent;
abaxial surface green or with silver-grey scales;
ramenta present or lacking. Inflorescence infrafoliar, a
divaricate panicle branched to 3 or 4 orders; bracts
2, fully enclosing inflorescence in bud; prophyll
fibrous; peduncular bract membranous, inserted
slightly above attachment of prophyll; rachis longer
than peduncle; rachillae flexuose. Flowers in triads
Figure 1 (left) - Archontophoenix alexandrae, Lamb Range,
north-east Queensland.
species
leaflet abaxial
(lower) surface
fruit shape
and length
mesocarp fibres
A. alexandrae
silver–grey scales,
ramenta lacking
ovoid–globose,
8–14 mm
mesocarp fibres to 1 mm wide, flat,
sparingly branched, remaining tight in the
dried state
A. cunninghamiana
no silver–grey
scales, ramenta
present
ovoid–globose,
10–15 mm
mesocarp fibres to 1 mm wide, flat,
branched, loosening in the dried state
A. maxima
silver–grey scales,
ramenta lacking
conic–ovoid, 11–15
mm
mesocarp fibres to 1 mm wide, flat,
sparingly branched
A. myolensis
silver–grey scales,
ramenta lacking
conic–ovoid–
elongate, 13–21
mm
mesocarp fibres terete or flat, thin to
thick, to 0.5 mm wide, branched,
forked about midway
A. purpurea
silver–grey scales,
ramenta present
ellipsoid to
globose,
20–26 mm
fibres flat, to 2 mm wide, branched,
overlaid and interspersed with thin fibres
A. tuckeri
silver–grey scales,
ramenta lacking
ovoid, 15–25 mm
fibres in two layers, the outer layer of
fibres thin, occasionally branched, the
inner layer thick, flat, to 3 mm wide,
mostly branched; fibres compact in the
dried state
Table 1. Distinguishing characters for species of Archontophoenix. Characters unique to a single species are highlighted in bold italics.
throughout or with paired or solitary male flowers distally on
the rachillae, spirally arranged. Staminate flower asymmetric
in bud; stamens 9–35; anthers dorsifixed; filaments curved
or deflexed. Pistillate flower smaller than staminate. Fruit
moderate, conic-ovoid to subglobose, red; stigmatic remains
apical to sub-apical; epicarp thin, smooth; mesocarp with
anastomosing fibres. Seed ovoid to subglobose; endosperm
ruminate; embryo basal. Eophyll bifid.
Archontophoenix is a genus of six species endemic
to Australia. Three of the species are narrow endemics that
are confined to either a single drainage system (A. myolensis),
or mountain ranges or massifs (A. maximus, A. purpurea),
while the other three have widespread distribution, one
confined to Cape York Peninsula (A. tuckeri), one to eastern
Queensland (A. alexandrae) and the other (A. cunninghamiana) to central Queensland south to southern New
South Wales. Species occur primarily as canopy emergents or
subcanopy elements in closed forests in high rainfall areas on
various soil types at low to moderate elevation.
Archontophoenix alexandrae and A. cunninghamiana
co–occur in the Eungella Range, where both grow at high
elevation in intermingled populations. There has been no
recorded evidence of hybridity between these species in
these natural populations, although hydridity may be
achieved by controlled pollination in cultivation. Characters
that distinguish species are presented in Table 1.
Archontophoenix alexandrae (F.Muell.) H.Wendl. &
Drude, Linnaea 39: 212 (1875)
Synonyms:
Ptychosperma alexandrae F.Muell.
Archontophoenix alexandrae var. schizanthera H.Wendl. & Drude
Archontophoenix veitchii H.Wendl. & Drude
Ptychosperma beatriceae F.Muell.
Archontophoenix beatriceae (F.Muell.) F.M.Bailey
Archontophoenix alexandrae var. beatriceae (F.Muell.) C.T.White ex
L.H.Bailey
Jessenia glazioviana Dammer
Trunk to 30 m tall, to 30 cm diam. Leaves 10–12, to
4.5 m long, becoming vertically orientated; leafsheath mid to
lime green. Leaflets 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
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Key to species
Perianth lilac to purple–mauve; leaflets dark green on both surfaces . . . . . . . . . . . . . . . . . . . . . A. cunninghamiana
Perianth white to cream; leaflets dark green adaxially, silver-grey abaxially
Mesocarp fibres less than 0.5 mm wide, unravelling in the dried state . . . . . . . . . . . . . . . . . . . A. myolensis
Mesocarp fibres to greater than 0.5 mm wide, remaining compact in the dried state
Leaflets with ramenta on abaxial midrib . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A. purpurea
Leaflets lacking ramenta on abaxial midrib
Flowers closely spaced on rachillae . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A. tuckeri
Flowers widely spaced on rachillae
Floral pits with margins round and low; raphe fibres in fruit strongly adherent . . . . A. maxima
Floral pits with raised sharp margins; raphe fibres in fruit weakly adherent . . . . . A. alexandrae
white to creamy green; rachillae to 30 cm long, erect to
semi-pendulous, moderately flexuose distally. Flowers widely
spaced on rachilla; floral pits with raised 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. Figure 1.
Common names: Alexandra Palm, King Palm.
Occurs in coastal Queensland from Melville Range
south to Baffle Ck. Grows on various soil types in rainforest,
swamp forest and moist sclerophyll forest at 0–1000 m alt.
Flowers all year; fruits all year.
Named for Princess Alexandra of Denmark
(1844–1925), daughter of King Christian IX and Louise of
Hessen–Kassel, married to King Edward VII of Great Britain
(1841–1910) in 1863.
Archontophoenix alexandrae is the most widespread
and prevalent palm in north-eastern Australia, contributing to
a characteristic landscape physiognomy, although most of its
former lowland habitat has been cleared for agriculture.
Large populations can be seen in the ‘Wet Tropics Bioregion’,
and it is well conserved in national parks and conservation
reserves. It most closely resembles A. maxima, from which it
differs by a less robust inflorescence and larger fruits, and A.
myolensis, which is distinguished by elongate fruit with
narrow, rather than wide, fibres in the mesocarp. These three
species have the abaxial surface of the leaflets with dense
silver–grey scales, and lack ramenta.
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Archontophoenix cunninghamiana (H.Wendl.)
H.Wendl. & Drude, Linnaea 39: 214 (1875)
Synonyms:
Ptychosperma cunninghamianum H.Wendl.
Seaforthia cunninghamii (H.Wendl.) Hort. ex F.M.Bailey
Loroma cunninghamiana (H.Wendl.) O.F.Cook
Jessenia amazonum Drude
Loroma amethystina O.F.Cook
Seaforthia nobilis Lhotsky
Trunk to 30 m tall, to 30 cm diam. Leaves 9–12, to
4.5 m long, becoming vertically orientated; leafsheath dark
green to green-purple. Leaflets 70-90 each side of rachis, to
100 cm long, dark green on both surfaces; ramenta present.
Inflorescence to 150 cm long, branched to 4 orders; axes
white to yellow green becoming mauve in infructescence;
rachillae to 55 cm long, pendulous, moderately flexuose
distally. Flowers closely spaced on rachilla; floral pits with
raised sharp margins; perianth lilac to purple–mauve;
staminate flower to 6 mm long; stamens 9–18; filaments
deflexed; pistillode about equal to petals; pistillate flower to 4
mm high. Fruit ovoid, 10–15 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, to 9 mm diam.; raphe fibres embedded,
strongly adherent. Figure 2.
Common names: Bangalow Palm, Piccabeen Palm.
Endemic to coastal Queensland and New South
Wales, from Mt Elliot (south of Townsville) to Durras
Mountain. Grows on various soil types in rainforest at
0–1200 m alt. Flowers all year; fruits all year.
Named for Allan Cunningham (1791–1839), British
Figure 2 - Archontophoenix
cunninghamiana, Kondalilla Falls,
south-east Queensland.
globose, 6 mm diam.; raphe fibres deeply embedded and
strongly adherent. Figure 3.
Common names: Walsh River Archontophoenix,
Herberton Range Archontophoenix.
Endemic to the Herberton Range and Mt Haig
Range, western Atherton Tablelands, north–east Queensland.
Grows on basaltic soils in rainforest and moist sclerophyll
forest at 800–1200 m alt. Flowers June–Aug,; fruits
Dec.–Mar.
Named in reference to the larger size of the inflorescence, and in particular the greater width of the peduncle as
compared to other species of Archontophoenix.
Archontophoenix maxima is distinguished by the
robust peduncle and the leaves which are held only
moderately laterally twisted, and not strongly so as in other
species of Archontophoenix. It most closely resembles A.
alexandrae.
Archontophoenix myolensis Dowe, in J.L.Dowe &
D.R.Hodel, Austrobaileya 4(2): 237, fig 1B (1994)
Figure 3 - Archontophoenix
maxima, north-east
Queensland.
botanist, who collected extensively in Australia, arriving in
1816 as ‘King’s Botanist to the Royal Botanic Gardens Kew’.
The relationships of Archontophoenix cunninghamiana to others in the genus are not clear; it is otherwise
characterized by leaflets that lack silver–grey scales, and the
presence of ramenta on the mid of the abaxial surface of the
leaflets. Sepals and petals of both staminate and pistillate
flowers are uniquely lilac to purple–mauve.
Archontophoenix maxima Dowe, in J.L.Dowe &
D.R.Hodel, Austrobaileya 4(2): 235, fig 1A (1994)
Trunk to 22 m tall, to 30 cm diam. Leaves 8–11, to
5 m long, becoming obliquely orientated; leafsheath mid
green. Leaflets c. 85 each side of rachis, to 90 cm long, dark
green adaxially, silver-grey abaxially; ramenta lacking.
Inflorescence to 140 cm long, branched to 4 orders; axes
cream-green; rachillae to 40 cm long, erect to semipendulous, moderately flexuose distally. Flowers widely
spaced on rachilla; floral pits with rounded low margins;
perianth white to cream; staminate flower to 6 mm long;
stamens 11–16; filaments curved; pistillode about equal to
petals; pistillate flower to 5 mm high. Fruit subglobose to
ovoid, 11–15 mm long, 7–12 mm wide; stigmatic remains
apical; mesocarp fibres to 1 mm wide, flat, sparingly
branched, remaining compact in the dried state. Seed
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Trunk to 20 m tall, to 30 cm diam. Leaves 9–12, to
4 m long, becoming vertically orientated; leafsheath blue
green. Leaflets 68-71 each side of rachis, to 110 cm long,
dark green adaxially, silver-grey abaxially; ramenta lacking.
Inflorescence to 160 cm long, branched to 4 orders; axes
white to creamy green; rachillae to 30 cm long, erect to
semi-pendulous, moderately flexuose distally. Flowers closely
spaced on rachilla; floral pits with margins not prominant;
perianth white to cream; staminate flower to 9 mm long;
stamens 14–24; filaments curved; pistillode about equal to
petals; pistillate flower to 5 mm high. Fruit elongate, conicovoid to ovoid, 13–21 mm long, 10–12 mm wide; stigmatic
remains apical to slightly subapical; mesocarp fibres terete, to
0.5 mm wide, sparingly branched, becoming unravelled in
the dried state. Seed ovoid-elongate, 14–20 mm long, 8–9.5
mm diam., raphe fibres strongly adherent. Figure 4.
Common name: Myola Archontophoenix.
Endemic to the Myola district, eastern Atherton
Tablelands, north-east Queensland. Grows on soils derived
from metamorphic rocks in rainforest at 350–400 m alt.
Flowers May–July; fruits Dec.–Mar.
Named for the locality of Myola, which is located
about 5 km west of the township of Kuranda, Atherton
Tableland, Queensland.
Archontophoenix myolensis is the rarest species of
Archontophoenix, confined to the Warril Creek drainage
system and nearby slopes, at 350–400 m elevation, on the
Atherton Tableland, west of Kuranda township, Queensland.
The population consists of only a few hundred mature
individuals, of which only a small percentage is conserved in
National Parks or nature reserves. The species’ rarity and its
population being within an area of urban expansion, places it
under considerable threat and it has an Endangered conservation status. It has been reported that the fruit and seedling
Figure 4 Archontopehoenix
myolensis, Warril Creek,
Myola, north-east
Queensland.
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morphologies are adaptations to riparian conditions: the fibres in the
mesocarp disassociate in the dried state and act as small hooks, which
enables the seeds to harness themselves amongst debris or within
sediments, and the seedling leaves become pinnate at a much earlier stage
than do other species of Archontophoenix [which suggests a possible
adaptation to fast flowing water]. The species is distinguished by the
elongate conic-ovoid to ovoid fruit, and with narrow, rather than wide, fibres
in the mesocarp.
Archontophoenix purpurea Hodel & Dowe, in J.L.Dowe &
D.R.Hodel, Austrobaileya 4(2): 238, fig. 1C (1994)
Trunk to 25 m tall, to 45 cm diam. Leaves 7–15, to 6 m long,
becoming obliquely orientated; leafsheath dark green to purple. Leaflets 5585 each side of rachis, to 105 cm long, dark green adaxially, silver-grey
abaxially; ramenta present on abaxial midrib. Inflorescence to 135 cm long,
branched to 4 orders; axes green; rachillae to 85 cm long, erect to semipendulous, irregularly flexuose distally. Flowers closely spaced on rachilla;
floral pits with raised sharp margins; perianth white to cream; staminate
flower to 7 mm long; stamens 20–35; filaments curved; pistillode about
equal in length to petals; pistillate flower to 6.5 mm high. Fruit ovoid to
globose, 20–26 mm long, 8–22 mm wide, red-crimson at maturity;
stigmatic remains apical; mesocarp fibres to 2
mm wide, flat, sparingly branched, interspersed
with terete thin fibres, remaining compact in
the dried state. Seed subglobose, to 23 mm
long, to 18 mm diam.; raphe fibres strongly
adherent. Figure 5.
Common name: Mount Lewis
Archontophoenix.
Endemic to north-east Queensland, on
Mts Finnigan, Spurgeon and Lewis. Grows on
granitic soils in rainforest at 400–1200 m alt.
Flowers Oct.–Apr.; fruits Sept.–Apr.
Named for the distinctive purple
colouration of the crownshaft - Latin purpureus.
Archontophoenix purpurea is one of
the most distinctive species in the genus,
having a prominent purple crownshaft and
large fruit. The colouration of the crownshaft is
due to three separate components of surface
indumentum. The innermost layer consists of
the dark blue–grey surface of the crownshaft, a
powdery glaucous bloom, and a dense
arrangement of reddish mahogany coloured
scales. From a distance the three components
merge to form the characteristic purple colour.
The fruit, at 20–26 mm long, are the largest in
the genus. They are red–crimson at maturity,
have prominent apical stigmatic remains, and
the mesocarp fibres are up to 2 mm wide. In
addition, the leaflets have a unique combination
of possessing both silver–grey scales and
ramenta on the abaxial surface.
Archontophoenix tuckeri Dowe, in
J.L.Dowe & D.R.Hodel, Austrobaileya 4(2):
240, fig. 1D (1994)
Figure 5 - Archontophoenix
purpurea, Mt Lewis, ca. 1100 m
altitude, north-east Queensland.
Trunk to 20 m tall, to 26 cm diam.
Leaves 7–12, to 3.15 m long, held flat or
becoming moderately obliquely orientated;
leafsheath lime green. Leaflets 43-68 each side
of rachis, to 93 cm long, dark green adaxially,
silver-grey abaxially; ramenta lacking.
Inflorescence to 60 cm long, branched to 3
orders, axes green; rachillae to 30 cm long,
erect to semi-pendulous, strongly flexuose
throughout. Flowers closely spaced on rachilla;
floral pits with raised sharp margins; perianth
white; staminate flower to 7 mm long; stamens
13–19; filaments curved; pistillode about equal
in length to petals; pistillate flower to 5 mm
high. Fruit ovoid, 15–25 mm long, 10–15 mm
wide; stigmatic remains apical; mesocarp fibres
two-layered, outer layer thin, terete, occasionally
branched, inner layer to 3 mm wide, flat,
branched, remaining
compact in the dried
state. Seed globose, 9
mm diam.; raphe fibres
weakly adherent. Figure
6.
Common names:
Rocky River
Archontophoenix, Peach
Creek Archontophoenix,
Iron Range
Archontophoenix.
Endemic to
north-east Queensland,
on Cape York Peninsula,
Lockerbie Scrub, Iron
Range and McIlwraith
Range. Grows on various
soil types in rainforest at
0–500 m alt. Flowers
June–Feb.; fruits
Aug.–Nov.
Named for
Robert James Thomas
Tucker (b.1955–d.1992),
horticulturist, botanical
illustrator, taxonomist
(Pandanaceae) and
landscape designer for
Townsville Botanic
Gardens, 1982–1992,
and designer of The
Palmetum, Townsville, a
botanic garden devoted
to palms. Tucker collected
palms and pandanus
throughout Cape York
Peninsula and was the
author of The Palms of
Subequatorial
Queensland.
Archontophoenix
tuckeri is distinguished by
the narrow elongate light
green crownshaft and
large bright red fruit.
Otherwise, habit and
general appearance is
similar to A. alexandrae.
The fruit, 15–25 mm
long, have been observed
to have an epicarp that
‘cracks’ at maturity, thus
exposing the mesocarp.
Figure 6 - Archontophopenix tuckeri,
West Claudie River, Iron Range,
north Queensland.
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