(Editor's Note: This article was originally published on February 8, 2009. Your comments are welcome, but please be aware that authors of previously published articles may not be able to promptly respond to new questions or comments.)
Rhapis is a small genus of palms containing perhaps 12 species--all from Asia, including South China, Thailand and several islands. These are mostly undergrowth palms, not known for their love of full sun, and are palms that tend to grow in high rainfall and moderately tropical situations. Despite their tropical origins, most of the commonly grown species are amazingly tolerant plants, surviving frosts, droughts, high winds and even some direct, hot sunshine. However where they excel the most impressively is in low light, indoor situations where they seem to be the perfect houseplant palm.
All Rhapis are fan (palmate) palms with typically deeply divided leaves. The leaves are so deeply divided that the leaflets look like separate entities and create the illusion of fingers off a hand. This appearance of slender fingers is where the common name Lady Palm comes from. The reed-like stems of these palms are where the other common name, Bamboo Palm, comes from. This is an unfortunate common name, however as there are literally dozens of other palms also referred to as Bamboo Palms which continues to cause endless confusion among inexperienced palm and houseplant collectors (nearly all the other species called bamboo palms also tend to make decent house plants just adding to the confusion.) Rhapis palms are the only palmate bamboo palms; all the others are pinnate species, and nearly all are Chamaedoreas. Rhapis palms are also sometimes refered to as dwarf fan palms, which is also the common name for a similar looking species, Guiahia argyrata.
Rhapis excelsa outdoors and typical fan/palmate leaf
one of the many 'Bamboo Palms' of the genus Chamaedorea; Guihaia argyrata, or 'Dwarf Bamboo Palm'; Rhapis excelsa growing right above a Guihaia in my garden showing how they look similar
Rhapis is a suckering species, spreading via underground runners (rhizomes) several inches to feet in all directions, but is slow to do so. Some species are more active spreaders than others. Some consider this an invasive group of palms, but in most gardens their spread is slow enough to easily control. In pots this spreading nature is obviously hindered, but eventually these potted plants become very root bound eventually necessitating their dividing, or at least moving up to a larger pot size. The dwarf cultivars are so slow growing that this eventuality takes decades to realize. The stems of these palms are either covered with a dense mesh of fibers or are partially naked, and are very stiff and straight, but only fractions of an inch in diameter.
Rhapis excelsa roots spreading under thin layer of asphalt; Single Rhapis excelsa spreading and being invasive
This is a dioecious genus of palms, meaning there are male plants and female plants, with no individuals producing both sexes of flowers. Some species can only be found in one sex. Rhapis humilis are all male and Rhapis laoensis are all female. These two species obviously have to be divided to be propagated, though division is the most common method of making more plants in all these species of Rhapis. The rest of the species can also be reproduced via seed production and germination as well. Seed germination is how the ‘sports' (variegated and unusual leaf forms) are created: amongst thousands of germinated seedlings a few oddballs develop and these are then grown up, divided and propagated for the nursery trade.
Rhapis excelsa lime colored plant with flower; Rhapis humilis flowers- all male
In general Rhapis are very easy to grow plants, requiring little fertilization, just water, soil (acidic is preferred), bright light (though many will tolerate very low light levels for prolonged periods of time), warmth (again, many will briefly tolerate temps well below freezing) and moisture. Most of the Rhapis species are also quite resistant to insect predation, another reason some make such exceptional house palms (no spider mites!)
This genus is not indestructable, and hot dry winds along with underwatering will kill it
The most commonly grown species of Rhapis in cultivation is easily Rhapis excelsa, or the Lady Palm. This plant can be found at nearly every garden outlet center as well as most of the larger nurseries throughout the U.S., and perhaps around the world. The reason for this is it is such an easy plant to grow and maintain, with excellent cold tolerance (down to about 20 F), low-light tolerance, modest drought- and wind- tolerance, and amazing pest-resistance. And it is one of the most ideal potted palms in cultivation. It is an easy plant to propagate both by division and seed production. Of course, it is also a beautiful palm; in all, an excellent starter palm or houseplant for those with little experience.
Outdoor and Bonsai Rhapis exclesas
Rhapis excelsa can be identified by its typical leaflets which end bluntly or raggedly, unlike most of the other common Rhapis that have pointed leaflets. Rhapis leaves typically have less than 8 to 10 leaflets per leaf (compared to Rhapis humilis or multifida which usually have more than 10, or Rhapis laoensis which usually only has 2 or 3.) These delicate, deeply split fan leaves droop from very thin petioles along most of the stem length making these palms look luxuriously bushy. If not watered sufficiently, the leaves start dying from the bottom up. Some landscapers trim the bottom leaves anyway exposing the stems for a more elegant look. The leaves often brown tip, for a variety of reasons, and landscapers will often keep cutting the tips back a bit with pinking shears to maintain the wonderful jagged look of the leaflets.
Rhapis excelsa leaf showing typical jagged/premorse leaf ends
Stems are heavily clothed in dark brown fibers and are about one-half inch in thickness. Sometimes stems are thinned out as well by landscapers and nurserymen to also increase elegance and beauty of the palm.
stems clothed in dark, tough fibers outdoor landscape plant with lower leaves cuta way to expose stems
Outdoors this is an excellent garden palm, and very easy to grow: just add water. It can tolerate full sun, but is happier and greener with some shade. If not contained, an individual palm can spread out over time covering many yards in all directions. Some plants at the Huntington Garden palm garden look like they extend over 30 feet wide. Grown in shadier conditions, these palms can get up to 8 feet tall or more, but tend to stay under 5 feet in full sun. These tolerate a variety of soils and grow fine for me in my heavy southern California clay soils. Cold tolerance is 18 F to 20 F, but much colder freezes will often only kill the above ground parts, and the plants will grow back in the spring, as long as the soil doesn't freeze as well.
Plants for sale in two different nurseries in southern California
Rhapis excelsa is the only palm species that has dozens of named cultivars, both variegated and not, and these are prized plants for pot culture all around the world, most notably in Japan. Some of these cultivars, most dwarf in size, can cost a huge amount of money. But plants, if taken care of properly, can survive several generations and be passed down in wills along with other family treasures. For an excellent coverage of the Rhapis cultivars and much more about this species, and some of the other Rhapis as well, visit the Rhapis Gardens website.
Rhapis excesla sports and cultivaras (middle photos is Rhapis 'Nanzan Nishiki'- photo gothqueen)
More Rhapis excelsa variegates (second photo of outdoor plant)
this is a very rare variety called 'Hiroshima' siince the leaves are constantly looking burned
More variegated palms I photographed in Thailand
Rhapis humilis is the second most commonly grown species of Rhapis and is known as the Slender Lady Palm thanks to its more slender leaflets. This species also can be identified by its having ten or more pointed drooping leaflets per leaf and tall, less fiber-covered stems reaching up to 18 feet in some old palms. Grown in the landscape, these spread a bit more slowly than Rhapis excelsas do, and seem to stop at about 8 feet in diameter. Few consider this an invasive species. Probably of all the Rhapis, this one tolerates sun the best, but still prefers some shade protection in hot, inland climates. I have never seen this grown as an indoor palm but reportedly it does very well as one; only a high ceiling is needed. As mentioned above, this plant only exists as a male, making many wonder if this isn't just a form of Rhapis excelsa. The ultimate origin of this species is unknown and there are no known ‘native' populations in the wild.
Rhapis humilis in California
Rhapis humilis as landscape palm in Hawaiian mall; as landscaping palms in Huntington Gardens, California; close up of stems
Another shot of Rhapis humilis in landscape; Rhapis humilis in landscape, with a clump of Rhapis excelsa in foreground for comparison
Rhapis multifida is probably the most beautiful of all the commonly grown Rhapis palms and is somewhat of a miniaturized version of Rhapis humilis with numerous very slender, delicate pointed leaflets making up each leaf. It is a shorter palm, normally only about 4 or 5 feet tall. Though plants can grow up to 8 feet in nature, I have never seen any specimen that tall. The stems of this plant are pencil-thin and nearly fiber-free and have a lot of visible green stem showing through. This is my favorite species of Rhapis and I have several growing about the yard. This plant does not tolerate drought and seems to need its roots wet all the time or it does not look good. This species cannot tolerate full sun well, particularly in arid climates. It is also less cold-tolerant, having some leaf damage when temperatures fall to the mid-20s. Some consider this a form of Rhapis humilis and include it in the same species, despite there being females of this ‘form'.
Rhapis multifida as potted plant in Singapore, and two shots of it growing in Hawaii
Rhapis multifida leaf unusual form with only few wide leaflets per leaf stems of Rhapis multifida
Rhapis subtilis is supposedly the dwarf species of the Rhapis (of the commonly grown ones, that is), but I have seen clumps of this plant in Hawaii growing at least 10 feet tall. This species usually has pointed leaflets, but there are blunt-tipped leaflet forms/cultivars. I personally cannot tell these blunt tip forms from Rhapis excelsa cultivars. It is certainly a very slow and somewhat picky grower and I have not had much luck with it myself. Its cold tolerance is about the same as Rhapis multifida, maybe even less so. And it really needs to be kept wet. It is a very variable species with a number of wonderful and unusual cultivars of its own (though I am not sure how many have names). I saw many varieties of this species grown as fantastic potted plants in Thailand (sadly, no digital camera back then.)
two Rhapis subtilis in Hawaii
Several rare cultivars of Rhapis subtilis in Thailand
Rhapis laoensis is another single sex species, only these are all females. This is easily the rarest species of the ‘common' species in cultivation, and is for me the finickiest of them all, never looking good in our southern California climate. It is a relatively small palm, growing maybe 6 feet tall at the most, and only forming narrow clumps of very thin-stemmed plants. Leaves are typically divided into 2 or 3 leaflets (sometimes a few more) with bluntly pointed tips. This species is easily the wimpiest of the above Rhapis in terms of cold tolerance, only barely tolerating temps below freezing. It is also needs water at all times, and develops brown tips if the water quality is poor or loaded with salts.
Rhapis laoensis in California
Rhapis ‘Alicia' is not a separate species, but is an officially named hybrid of Rhapis laoensis and Rhapis multifida. This is a wonderfully ornamental mixture of these two plants, having the sparser, elegant leaflets of laoensis, the narrow, pointed graceful leaflets of multifida and the pencil-thin, barely fiber-covered stems of Rhapis multifida. Its cold tolerance is at least as good as multifida if not even better and it is even a tad sun-tolerant. However it certainly isn't the most wind tolerant Rhapis, and mine tends to look pretty tattered after Santa Ana wind season here in southern California.
Rhapis 'Alicia' in Southern California growing in garden of original hybridizer, Louis Hooper; leaf of Rhapis 'Alicia'; Flowers of Rhapis 'Alicia'
Seedling in first photo; shot of nearly naked stem in second
I know little of the other Rhapis species and have only seen rare examples of any of them in cultivation. Perhaps someday some of these will also be wonderful available palms for cultivation, both indoor and out.
Other species of Rhapis I have seen (from left to right): Rhapis robusta, Rhapis micrantha, and recently this last plant, Rhapis 'Nova Laos' has become available out of Hawaii