The popular Washingtonia genus counts three species. The W. filifera, the W. robusta and the hybrid W. filibusta. These are however very much similar, so only an practiced eye can really determine the species with certainty. In this article you will learn what characteristics you should look for to make the distinction.
Filifera vs robusta
The most common species are the Washigtonia filifera and the Washingtonia robusta. Both are the the most easy to separate from each other if you know what to look for. The filibusta is a bit more complicated, further on more about this species.
Nb. Young plants look very similar and are therefor harder to determine. This is why we mainly will show/discuss older subjects.
Petiole (base)
Filifera
Only slightly colored (reddish-brown), limited to the base.
Robusta
Strongly colored deep purple-brown on widely spread and continuing on the petiole. If the old petioles weren’t cut very short the coloring isn’t always that obvious.
Petiole
Filifera
Covered with spines but not as many and aggressive and placed more irregularly. They aren’t always colored as much. The last few cm’s/inches of the petiole close to the leaf base lacks spines (or the are negligible).
Robusta
Covered with spines, aggressive, placed regularly and colored. Especially those spines that continues all the way through to the leaf base is a strong characteristic.
Hastate and trichomes
Filifera
The hastate (the spear like end where the petiole meets the leaf) is relatively long and is not covered with hairs (trichomes) on the sides. (2nd photo).
Robusta
The hastate is shorter. On the bottom side of the leaf the hastate is also covered with hairs on both sides. (trichomes: see 2nd photo).
Leaf
Filifera
Off green color, leaf segments are deeply cut out, below the 50% mark.
Robusta
Deeply green, shiny, leaf segments are not cut out any deeper than the 50% mark.
Stem
Filifera
Proportionately and symmetrically formed.
Robusta
Irregularly shaped with a clear thickening at the base.
Total impression
Filifera
Remains more compact than the robusta.
Robusta
Looks impressive, voluptuous. Will be bigger than the filifera.
Washingtonia filifera
Washingtonia robusta
Filibusta
This species is a hybrid, or crossbreed, between the robusta and the filifera. Both species can carry the seed. The mother plant determines the type of hybrid. A filibusta type filifera is derived from a female filifera pollinated by a male robusta and vice versa.
© La Palmeraie
Reactie door Francesco Delvillani — 11 oktober 2017 20:54 @ 20:54
Thanks,very usefull. It’s pretty difficult to understand what Washingtonia you’re seeing..
Reactie door lapalmeraie — 12 oktober 2017 06:31 @ 06:31
Hi Francesco
Thank you!
Once you know what to look for it becomes a lot easier.
Especially the color of the leaves that are a lot less bright and shiny on the filifera (more grayish) in combination with the leaflets that are way deeper cut out.
Kind regards
La Palmeraie
Reactie door Catmanna — 16 juni 2019 13:49 @ 13:49
Ugly tree, what’s with the bottom pic that looks like one is falling over?
Reactie door lapalmeraie — 17 juni 2019 05:06 @ 05:06
Hi Catmanna
I actually do like the looks of this palm tree which happen to be « as exotic as it gets » here up in Northern Europe. Of course I would prefer a nice Bismarckia but that’s just wishful thinking.
By the way, nothing is falling over, the last pic is just a detail of the petiole and hastula to show the characteristics in detail.
Kind regards
La Palmeraie
Reactie door Daniel — 1 oktober 2019 12:10 @ 12:10
Great article. It is really helpfull.l and very clear.
Thank you by your time to share your knowledge to the community.
I only have Instagram account. If you desire ti follow is @palmportugal
Reactie door lapalmeraie — 1 oktober 2019 14:44 @ 14:44
Hi
The pleasure is mine!
Kind regards
La Palmeraie
Reactie door Tom — 1 november 2019 11:15 @ 11:15
I grow Bismarckia, but wind breaks its fronds, so does for Washingtonia as well, messes with the fronds.
Reactie door lapalmeraie — 4 november 2019 06:13 @ 06:13
Hi Tom
You must live in quite some windy environnement then! How does the Jubaea holds up in those conditions?
Kind regards
La Palmeraie
Reactie door Tom — 4 november 2019 22:00 @ 22:00
Hi La Palmeraie,
I am at Pico island, Azores, very windy indeed at times. Went through a mild hurricane recently. Unfortunately I do not have a Jubaea in my garden collection yet. CIDP hold to the wind best, but also Butias, Hyophorbes, Arecas, Copernicias, Kentias, Phoenixes do well in our winds.
Greetings,
Tom
Reactie door lapalmeraie — 5 november 2019 07:48 @ 07:48
Hi Tom
Wow! That’s quite something. Did you also tried the Cocus nucifera? That one should cope better with storms I guess.
Kind regards
La Palmeraie
Reactie door Tom — 6 november 2019 20:12 @ 20:12
Hi La Palmeraie
I will try Cocos nucifera. They will not bear (edible) fruit here most likely, but they do grow here at least I know one guy is growing it.
Kind regards
Tom
Reactie door vegetable gardening — 29 december 2023 18:32 @ 18:32
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finally got the courage to go ahead and give you a shout
out from Houston Texas! Just wanted to mention keep up the
great work!
Reactie door lapalmeraie — 30 december 2023 12:09 @ 12:09
Thank you!