Arenga ryukyuensis- new species ?

[Eric in Orlando]

I got Henderson's new book, "Palms of Southern Asia" the other day. In it I notice he has Arenga ryukyuensis described and says it is often confused with Arenga engleri, grows to 2m tall and is native to the Ryukyu Islands. Arenga engleri is described as growing to 4m and native to Taiwan. Sounds like the hardier, shorter form of A. engleri has been split out as a seperate species, A. ryukyuensis.

Checked Kew's site and they now have Arenga ryukyuensis listed, also. Guess I have some labels to change.

[redbeard917]

Interesting... For those of us who are in colder areas, what is the difference in hardiness between the two?

[Alberto]

A week ago I noticed the difference between the Arenga engleri I´m growing. From RPS seeds the plants has broader softer leaflets and one of the arengas that i got in São Paulo has very hard short leaflets. I photographed both to post here and forgot about it. Could this be the two species?????

[iwan]

Eric,

Is there any difference in seed size between the two? I acquired seed from two different sources and there was a substantial size difference between the two batches (both were viable).

[edbrown_III]

I bought Arenga engleri many years ago.. I bought clumps on two occaisions. I have a taller one by the house and a shorter one. The taller one went through 85 and both of them went through 89 --- killed to the ground but came back from roots--

Very cold in 85' probably 10 or 11 here. Walter Rogers had a huge clump at his house-- the taller one it went through all the freesez -- 77-present

killed to the ground--- I think the trunks are good to may 16-18F but they come back. ----I have may be 1/2 dozen around the yard--- kind of makes me feel like I am in the Philippines if plannted with Bamboo.

Best regards

Ed

[Eric in Orlando]

In his description of the 2 species these were the major differences

A. engleri;

stems to 4m and 15cm diameter

leaves to 3m long

inflorescences to.6m long and up to 15 flowering branches fruits to 1.5cm

A. ryukyuensis;

stems to 2m and 20cm diameter

leaves to 2m long

leaflets strongly ribbed on upper surfaces

inflorescences to.5m long and up to 30 flowering branches

fruits to 1.8cm

Iam going to go check our 2 forms and see if our Ryukyu Is. forms has ribbed leaflets

[Eric in Orlando]

I went out between the deluges of rain and checked out the leaflets on 2 specimens of the 2 forms that are growing near each other. The smaller supposed Ryukyu Island form has leaflets that are 17-19 inches long and does have some slight ribbing. The leaflets on the big Taiwan form are smooth and are 27-32 inches long.

[Pal Meir]

I little bit late, here two links to photos of Arenga (engleri var.) ryukyuensis taken in 1987 on the islands of Iriomote, Ishigaki, and Okinawa, showing the palm in its natural habitat:

Panoramio/GoogleEarth: http://www.panoramio.com/user/7128744/tags/Arenga%20ryukyuensis

Flickr: https://www.flickr.com/photos/palmeir/sets/72157632190734072