Help ID Palm Trees, California

Hi, I'm hoping for help identifying the palms in the attached photos - mainly because I'd like to have an idea how tall they will likely grow. Location is in the San Francisco Bay area. The taller of the two (with the visible windows behind) appears to have a trunk about 25 feet tall, and they were planted here about 7-8 years ago, when they were just a few feet tall. Significant growth has occurred in the past year.

Thanks for any help,
George Griffeth

 

I am still digging - but recall that the vegetative trait (called a hastula) at the intersection between the leaves and petiole is quite distinct between species, as is the position at which the leaf blades fuse (the average depth as a percent of the overall length of the leaf before the leaf blades fuse). Your plant does not have marcescent leaves yet (dry leaves that form a "skirt" below the canopy of new growth), but in other respects it does look like Washingtonia robusta.

 

Many thanks, Susan, for the recollecting, further digging, and explanations! I've taken and posted an additional shot showing the leaves. The central, horizontal leaf is in close to correct proportion (not shot at an angle), and the petiole (new word) appears to be easily a yard in length - you've got me reading up on Wikipedia. Looking at the pix of mature Washingtonia robusta there and reading their typical mature height, I can say only - OMG!

Thanks again,
George

 

the shape, projection, length, and "hair" details of the hastula are distinct. It is a small triangular shape in your photo and shows pretty well. Scale is inexact, but my guess is that it is an inch wide in your photo. There are a few shots in Google images too. The petiole is indeed that long spiny part between the palm and the trunk.

You can compare your hastula to a hastula found on W. robusta - at your nursery - in Berkeley you would want to try Berkeley Hort.

Yea. If it is W. robusta, they do get tall.

 

W. robusta is a fast grower, W. filifera painfully slow.

 

Thanks, saltcedar. It's been putting on four or five feet a year - that seems like robusta growth to me, supporting Susan's ID (thanks again for additional info, Susan).

I really appreciate the help.

-George