Without a picture it is hard to be certain, but saying that it has multiple pups at the base makes it most likely to be Aloe arborescens, as few other true tree aloes will branch from the base. I don't think I ever noticed a bad smell while working/pruning an Aloe arborescens, but they definitely are prolific and slimey foliaged when you break a leaf. Did your son say whether this one was blooming now with typical deep red flower spikes in quantity over large shrubs? If so, it is almost certainly A. arborescens. There is also a nice yellow flowered cultivar that blooms here as early as October.

thanks! I think you're right after looking at pictures online. I don't think he ever saw it blooming. It is a really beautiful plant.

Actually there are well over a dozen tree aloes (which Aloe arborescens is not really considered one- more of a shrub) that branch at the base. If you include shrubs like A arborescens the number of possibilities goes well over 30 different species. However Aloe arborescens is certainly one of most common species in cultivation so it is a good guess.

This one is about 2-3 feet tall, has a "trunk" much like a yucca or palm makes a trunk as old growth dies away. the main plant on top of the trunk is about 18" wide. The "pups" or "suckers" form at the base (again much like a yucca). I've never seen these before in Texas, but maybe it is common in the Bay area. Would like to get one also, so that is why I am trying to narrow down what it is. Maybe we'll get lucky and it will bloom and we'll be able to narrow it down. This is surely an exotic plant here.

Here are a few possibilities, just to show you how difficult it can be to narrow something down without a photo. By the way, at last count, this is less than half the possible species/hybrids. All these sucker at the base and are either tree or shrubby aloes with at least 2' of stem (most have a lot more)

Aloe speciosa

Aloe scorpioides

Aloe rupestris

Aloe rivierei

Aloe rabiensis

Aloe principis (an Aloe ferox hybrid)

Aloe pluridens hybrid

Aloe pluridens

Aloe penduliflora

Aloe ngongensis

Aloe nyeriensis

Aloe mudenensis

Aloe kedongensis

Aloe hardyi

Aloe divaricata

Aloe cheranganiensis

Aloe fibrosa

Another form of Aloe ferox hybrid

Aloe castanea

Aloe andongensis

Aloe africana

Aloe acutissima

Aloe ramossisima

Aloe mutabilis

oh, and lastly, two forms of Aloe arborescens

any look familiar?

Wow! Very cool pics! Nicely done...

Here is a link that might be useful: okcpalms.com

The picture of Aloe cheranganiensis is the closest looking in form and color. Thanks for all the nice pictures!

Some fantastic shots of various shrubby Aloes. I don't know that I would consider all of them within the "tree aloe" category from a landscape design point of view, but it is an arbitrary division in any case. Are most of these photos from plants at the Huntington or LA County Botanic Gardens? Some truly incredible photos, and few of these would ever be seen in such vigor and size up here, with the exception of the Ruth Bancroft Garden in Walnut Creek and the UC Berkeley Botanic Garden.

I still suspect that the cuttings taken back to Texas are mostly likely smaller leaved side shoots from Aloe arborescens, unless your son had access to a collector's garden. A. arborescens is THE most common larger aloe here in the SF Bay Area. While the species grows over much of South Africa and no doubt has wide tolerance for different conditions, I don't think it is likely successful anywhere it regularly drops below 25F each winter for several days, or where the summer nights are hot and steamy and don't cool off. Is anyone here growing this successfully in Texas or south Florida? Also, being a winter bloomer, flowers can freeze even when the foliage resists; and this isn't a particularly attractive foliage aloe to grow for form/texture alone.

Of the other Aloes in the photos, the ones I've seen most commonly and/or grown in gardens include speciosa, pluridens, ferox, castanea, africana, arborescens, thraskii, marlothii, x spinossimus to list a few. Here's some photos of them in SF Bay Area gardens:

Here is a link that might be useful: Aloes in the East Bay Area

not sure if this will work--here is the picture

http://photo2.walgreens.com/walgreens/slideshow/AlbumID=9825979005/PictureID=343077703005/a=24095640_24095640/otsc=SHR/otsi=SPIClink/COBRAND_NAME=walgreens/

Here is a link that might be useful: tree aloe

does indeed look like an Aloe arborescens (a shrub rather than a tree aloe)

Wow, great pics! I really like Aloe andongensis

I remember Rian had a photo of a fairly towering A. arborescens in native habitat that was indeed a tree, peeking out between actual trees, competing for sunlight. It was rather a surprise.

This is a climbing aloe vera

I can't see the picture. Your description of the plant stinking when the leaves break makes me think it could be A. pluridens. If it is, be sure to wash hands after handling. A. pluridens and A. fibrosa are both poisonous plants.