Editing Rhapis excelsa

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[[File:Rhapis_ex_broad.jpg|frame|Figure 1. ''R. excelsa'']]
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''Rhapis excelsa'' is a multi-stemmed dioecious
(Ed: or hermaphroditic depending on seed grown variety) palm that
grows to a maximum height of between 3 and 4 metres, each
stem or cane is slender ranging from 10-30mm in diameter,
depending on growing conditions and variety. The canes are
usually covered by a coarse matted fibrous material which is
actually the outer base of each leaf sheath. In
''Rhapis excelsa'' this leaf sheath fibre tends to be
loose and rather ragged looking. The leaf sheaths are fairly
persistent but when they do fall a dark green conspicuously
ringed stem of leaf base scars is exposed: very similar in
appearance to bamboo canes, hence the other common name
bamboo palm. Individual canes can be closely ringed, or rings
may be moderately spaced, depending on growing conditions.
In ideal growing conditions leaves are palmate, deep glossy
green thick textured and divided into regular fairly broad
segments usually to near the junction with the petiole but
not always so. Mature palms which I have observed have from
five to twelve segments per leaf with rather raggedly toothed
ends of each segment. Segments are conspicuously ribbed and
outer and inner segment margins are minutely toothed. Petiole
is slender, often covered with a fine grey or brownish grey
fluffy hair. The leaf blade may be up to 80 centimetres
across, arranged in a semi-circle just greater than 180&#176;.
The petiole or leaf stalk may be up to 60 centimetres long
although it is usually shorter. The leaf sheath may be up to
60 centimetres long, the edges of which are composed of brown
or grey-brown fibres.
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Inflorescences emerge from between the leaf sheath and stem
and usually arise from the uppermost portion of the stem. On
emerging the inflorescence has a pale pinkish tinge and is
enclosed in pale green tubular bracts. As the inflorescence
matures the bracts dry up and become brown and papery in
texture. In my offset grown plants, the inflorescence is
branched to second order on female plants and to third order
on male plants and, as most of my plants are to third order,
I seem to have a predominance of male plants. Inflorescences
are relatively short, brittle or stiff and tend to droop,
flowers are arranged spirally on the second and third order
branchlets and male flowers have a three lobed fleshy calyx,
fused at the base. Male flowers have three petals which are
fleshy and fused at the base and have six stamens and three
small aborted fused pistils. Female flowers are similar but
are not as elongated, the stamens are minute and there is a
prominent three-part pistil. Ripe fruits are white to cream,
rounded and approximately 36mm across.
 
One of the reasons for this palm's popularity is its ease of
culture. ''Rhapis excelsa'' is very adaptable to soil
types although neutral to slightly acid soils with good
drainage and organic matter is recommended for best results.
This palm as is the case with most ''Rhapis'' species is
an understorey plant so for best results a partially shaded
spot under trees or a pergola is ideal.

''Rhapis excelsa'' can be grown in full sun as long as
soils are good and adequate water is available. Leaves
however, will lose their deep green colouring, will become
yellowish green and on the hotter days will probably burn.
Temperatures as low as -5&#176; C are tolerated by
''R. excelsa'' as it is quite cold hardy, particularly
when grown under shelter, and it also grows in climates where
it may be exposed to prolonged periods of cold weather. Very
hot weather, particularly when the air is very dry, may cause
damage which can be prevented by adequate watering, mulching
and growing under other plants or pergolas and occasional
hosing of foliage with a fine spray or mist can also help to
maintain a higher relative humidity.
 
As an indoor plant '' Rhapis excelsa''
has no palm rival (Not even ''[[Howea forsteriana]]'').
Its ability to handle
low light intensities, low humidity, varying temperatures
plus its suitability to pot culture, small to moderate size
and slow growth rate make this palm ideal for indoor culture.
'' Rhapis excelsa''
has very few pests or diseases to trouble it. The only major
pests are scale and mealybug. Scale can be easily controlled
by physical removal, wash off with high pressure jet of water,
or scrape off with cotton wool buds, or by chemical control
with White Oil, or a systemic insecticide such as Rogor or
Metasystox. Mealybug can be removed physically but it usually
requires chemical control. For total control use a systemic
insecticide and apply as a soil drench as mealybug often
invades the roots of a plant, However, pest disease problems
are few. The only problems I have had being root rot caused
by fungus attack because of poor cultural practices and brown
or black fungal spot on the leaves, usually symptomatic of
poor nutritional status.

Root rots can be avoided through proper cultural practices
such as choosing healthy plants in the first place and
watering only when necessary. Provide good drainage so that
water does not build up and stay around the roots of your
plants. This means plant in raised beds when planting into
poorly drained ground, or opening up the soil by adding
organic matter or coarse sand or, in pots or tubs use potting
mixes that conform to the Australian Standard. Poor drainage
is the single most common reason for root rot in potted
plants and, with stale water continually surrounding roots a
low oxygen environment develops which is ideal for root rot
to take hold.

But if, despite great care, root rot symptoms
do develop, such as wilting, excessive browning of leaf tips
and loss of vigour, firstly remove the plant from the soil it
is in, wash roots bare of soil, inspect roots for fungus
problems, remove black roots or reddish-brown roots and
replant into a raised bed of well drained soils. In the case
of tub or potted plants do the same but plant into a clean
well drained potting mix and, finally, drench the soil with a
systemic fungicide such as Fongarid or Terazol or similar.
Brown or black fungal spot is usually caused by poor
cultural practices. To prevent the disease, buy only good
quality plants and don't crowd plants too much so as to allow
unimpeded air flow to reduce conditions ideal for the fungus.
If leaf spot does occur remove and burn the affected leaves.
Thin out plants or space potted plants to improve ventilation
and finally spray all affected plants with a preventative
fungicide such as Benlate or Mancozeb.

For best results water only when the first few centimetres
of soil or potting mix are dry and then water thoroughly so
that there are no dry areas around the plant roots. In well
drained soils and mixes this should result in a good balance
of water and air. The large amounts of water leach out
accumulated salts, toxins and carry oxygen to the roots. The
better the quality of water applied the better your plants
will grow in the long run, particularly plants grown in
containers. Plants held indoors benefit by being taken
outside when it is raining or being placed under a sprinkler
for a period of time. Brown leaf tips are often caused by an
excessive accumulation of fertiliser salts in the potting mix.
Thorough leaching will overcome this problem.

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[[File:Rhapis_excelsa.jpg|frame|Figure 1. ''R. excelsa'' (on left) next to ''R. humilis'' in Naples Botanic Gardens.]]
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[[File:Rhapis_inflor_m_.jpg|frame|Figure 3. ''R. excelsa'' inflorescence.]]
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[[File:Rhapis_excelsa02.jpg|frame|Figure 4. ''R. excelsa'' spectacular inflorescence.]]
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===Contributed by: ===
Heinz-Dieter Froehlingsdorf (Text) (from '''''Palms & Cycads''''' No 39. Apr-Jun 1993).<br/>
Angelo Porcelli (Figure 2).<br/>
Ray Hernandez (Figure 4).<br/>
Ian Edwards (Figure 1&3)


===External Links:===
[https://powo.science.kew.org/results?q=Rhapis%20excelsa Kew], 
[https://www.palmweb.org//?q=cdm_dataportal/taxon/ffd5df6a-3adf-4c22-8b21-3db916fc3c79 PalmWeb],
[https://e-monocot.org/taxon/urn:kew.org:wcs:taxon:177959 eMonocot],
[https://www.jstor.org/action/doBasicSearch?Query=Rhapis+excelsa JSTOR],
[https://www.trebrown.com/plant_info.php?species=Rhapis+excelsa Trebrown],
[https://www.floridata.com/ref/r/rhap_exc.cfm Floridata],
[https://en.wikipedia.org/wiki/Rhapis_excelsa Wikipedia]
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[https://www.google.com/search?q=%22Rhapis+excelsa%22&amp;num=10&amp;sa=Google+Search Google],
[https://images.google.com/images?q=%22Rhapis+excelsa%22&amp;hl=en&amp;btnG=Google+Search GoogleImages],
[https://www.flickr.com/search/?q=Rhapis+excelsa Flickr],
[https://www.google.com/search?q=%22Rhapis+excelsa%22%20site:https://www.palmtalk.org/&amp;sa=Google+Search PalmTalk]
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[[Category:Rhapis|excelsa]]
[[Category:Palm|Rhapis_excelsa]]