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This plant is a hybrid created by David Verity during his time as curator of the Mildred E. Mathias Botanical Garden at UCLA from the 1960s to the 1990s. Its parentage is A. ×spinosissima × A. marlothii. The super spininess of this plant is in large part derived from A. marlothii, but may have been enhanced by some genes from Aloe ×spinosissima, which is itself a hybrid with following parentage: A. humilis (the toothy form known as var. echinata) × A. arborescens.
This plant is not known to reach the large sizes associated with A. marlothii or the bushiness of A. arborescens, instead the diminutive size of A. humilis causes the mature size of this plant to be just over 1' across.

Here in the Valley of the Sun, the plant enjoys some shade in the afternoon but can take full morning sun. It has not yet flowered for me.

This is a very rewarding Agave to grow. It generally has a very nice shape as its common name, 'Octopus Agave,' already suggests. It does tend to lean towards the sun a bit as it grows. Given its relatively thin leaves, it is surprisingly resilient in terms of sun exposure here in Arizona, where plants almost seem to do best exposed to as much sun as possible. It does like some summer water, but takes neglect very well.

Size-wise, this plant would fall in the large-medium sized Agave category, it does not get humongous, but it does attain a pretty good mature size in the 4-5 foot tall range and 6-8 foot diameter. While I have seen some pups/offsets, most plants are solitary, but it makes up for that when flowering!

As Agaves go, this is also one of the less dangerous ones. Its leaves are generally toothless, though some have very, very small teeth that are closely spaced, but they tend to be pretty soft and not harmful. There is a terminal spine, but the leaf ends are pretty pliable and there is not a lot of danger of impalement, which you do get with many other Agaves. It is always a good thing to be careful around Agaves, though.

In terms of reaching mature flowering age, Agave vilmoriniana is relatively quick, with most plants reaching flowering size in 5-10 years. When it does flower, it puts up a tall spicate inflorescence that tends to remain erect and is densely populated with flowers, as can be seen in the many pictures associated with this entry. The flowers are yellow, and while the plant does set seed, it also produces an incredible abundance of bulbils on its flower spike that are best harvested when there are 3 sets of leaves on the bulbil. The bulbils readily root and make this a very easily propagated plant. As with almost all Agaves, the main plant will die after flowering, though I have seen some specimens hang on, looking somewhat reasonable for many months after the flowering event is over.

I grow my plant in full sun and only during the hottest parts of the summer does it suffer a bit, but generally a regular once per week/two weeks watering regime keeps it looking good.

Agave sisalana will get really large. I have seen several plants at flowering age that were at least 8 feet tall, if not a little larger. The leaves are stiff with mostly smooth edges, though on occasion small teeth might be present. The terminal spine is not overly large, but combined with the stiff leaves it does make the plant dangerous as they will easily pierce clothes and skin. The leaves generally have an upright posture, but older leaves will slowly fold down towards the ground, giving the plant a nice shape.
The leaf color is green to glaucous grey, and in the right conditions the leaves will show banding.
The leaves are extremely fibrous and therefore the plant is still used for fiber production. If you have ever bought sisal rope, you will have bought rope made from Agave sisalana. Because of this use, plants have been exported from central America to places in Africa and elsewhere where growing conditions are similar.

Originally these plants were from a more tropical environment than Arizona, but plants take the full summer sun here without any problems. They do not like the cold, though, and plants have gotten damaged by temperatures around freezing, so they are not good in-ground plants for climates that have regular winter freezes. While this plant can be kept as a potted plant, it will eventually outgrow most reasonably sized pots that can be moved around easily, so this is really an in-ground plant.

As can be seen from the images in the database, when it flowers the plant puts up a tall thick inflorescence with many bracts, on which it will carry many yellow flowers. These open sequentially from the bottom to the top of the inflorescence. Unfortunately, the plants that I have seen flowering were not kept around long enough to be able to observe whether they make bulbils.

All in all, this is a very nice plant that can form a great centerpiece in any xeric garden with enough space and mild winters.

This is a very interesting and wonderful plant that has become more widely available in recent years and with it comes an interesting controversy: The original description of the plant by Howard S. Gentry would appear to only include room for the white-grey version of the plant to be the actual true form of Agave titanota.

However, as one can see from the photos for this plant posted in the database there are green versions that otherwise look very similar to the white-grey versions that you can find at botanical gardens and nurseries also named Agave titanota. While work is in progress to try and sort out if these green plants are indeed just green versions of Agave titanota or represent something different: either a hybrid or a completely new species, the fact that these green plants are very variable and some times can be grown from seed that purportedly came from the white grey form, makes for a complicated situation.

Interesting tidbits that I have learned from people who have actually visited the type locality of Agave titanota as described by Gentry and where he collected his specimen plants: Within the area of the type locality no green plants where observed, the white grey plants there appear to grow only on limestone substratum. The first green look-a-likes are encountered a significant distance away from the type locality in an area where they are close to and overlap with other Agaves, significantly among those another quite variable Agave: Agave kerchovei. These plants are growing on mixed substratum not solely limestone, and while most are green there are blue/grey-green plants among them.

So the jury is still out, but if you are growing and enjoying a nice green 'Agave titanota' do not be surprised or upset if there are certain purists around that would strongly disagree with that plant as being an actual Agave titanota.

As to growing them: here in Mesa, AZ, where we get to deal with the full on AZ summer and a strong heat island effect these plants enjoy a little bit, but not too much shade to look their best. So in areas where the summer is less extreme these plants should have no problem with full sun. Plants enjoy regular summer water and would probably not mind some limestone soil amendment. Since it has not really been very cold here during the winter in quite a while, I cannot speak to this plant's cold hardiness.
Both my white grey and my green specimens offset regularly when the plants are settled in and happy, most of these offsets are basal stem offsets though and they are not that easy to remove, but offsets should have no problem rooting.
As plants mature they appear to slowly but surely become less fierce looking, with the extremely toothy leaf margins becoming much less so.

While this plant grows in the desert, it is a coastal desert and the plant is not actually succulent, ie. it does not store water. It will die quickly if it completely dries out. So while it can be suitable for xeriscape, it needs a reliable source of water. In its native habitat the taproot grows to tap into deeply located water sources while it develops a network of shallow roots that capture moisture from fog/mist derived from the nearby ocean. This shallow network is usually not observed in plants grown in pots or out of habitat.

This is a very large growing arborescent prickly pear. Its spineless to nearly spineless version was preferentially cultivated to serve as cattle feed, so most plants encountered in cultivation are of the spineless variety. The young pads (which are not leaves, but stem sections) of this cactus can be harvested and are edible, but still need to be cleaned of their glochids. The fruits are called 'Tunas' and are also edible.

Even though the prickly pear has no spines, one should still take care when handling the pads because the fine barbed hairs that grow on the glochids can easily get stuck in exposed body parts. are hard to impossible to remove, and are very irritating. With time the main trunk of the plant will become woodified and really hard and strong, and will turn grey-brown iso green.

The habit of this cactus changes with the amount of sun exposure: Plants grown in full sun to mostly full sun tend to spread out rather than growing super tall (though they still easily reach 10'). Plants grown in more shade tend to grow taller rather than wider, easily reaching 15-20 feet tall. Because of its eventual size, this is not a cactus that is really suitable to grow in containers. If grown in containers, the cactus will never reach its full potential and is not very likely to flower, or flower profusely, so this plant is better grown in the ground, but be sure to give it plenty of space. In my yard I use it as both a hedge and shade tree for smaller plants that are not quite as happy in the full summer sun here.

Someone listed this plant as deer resistant, and since we have no deer in my urban environment I cannot confirm or dispute that, but this prickly pear is most certainly not Javelina resistant: Young plants can be eaten to soil level by a family of Javelinas in no time. Mature plants tend to survive as Javelinas tend to go for the young growth, but frequent grazing of the new growth will stunt the plant's growth.

In all recent literature this plant is considered either a variety or subspecies of Echinocereus viridiflorus.

The 'Silver Peso' cultivar of the Texas Mountain Laurel generally has the same characteristics as the regular Texas Mountain Laurel except that its leaves have a grey-silver sheen to them, which sets it apart from the regular version.
I bought two of these to replace a fallen down Desert Museum Palo Verde, but these are very slow growers compared to the Palo Verde, which in the 4 years since falling over has grown back into a big sized tree, whereas the Texas Mountain Laurels are just now going on 5 feet tall or so.
They make for beautiful landscape plants, though, and the flowers are very pretty and fragrant, sweet and fruity smelling.
Here in Arizona the bush is an attractant for a small moth (the sophora pyralid moth) that lays its eggs on the plant, and the caterpillars can be quite destructive to young growth. For me the damage has been mostly cosmetic - ie. no lasting damage, except for possibly some growth retardation.

Growing Aloe 'Hercules' in Mesa, AZ:

I have been growing one of these in my front yard since about 2008. I started it from a 2-3 foot tall plant that I got at a wholesale nursery in Phoenix.
How it deals with the low desert AZ sun: Having heard that these may not be capable of taking the summer sun, I started it out next to a 'Desert Museum' Palo Verde to provide midday to late afternoon shade, while the house provided shade for a good part of the morning. Very soon after I put the plant in, we lost the shade tree in a big Monsoon storm and for the next three years I ended up putting a shade structure over it during the hot summer months. Since we never took the stump of the DM Palo Verde out we had a decent sized tree back right at about the time the 'Hercules' got too large to build a shade structure over.
However, since then the 'Hercules,' which is going on 15 feet tall and has branched, has outgrown both the shade of the house and most of the shade of the shade tree. It gets some late afternoon shade in the summer (which is good). It has dealt with that amount of sun pretty well. It gets some sun-burned leaves, but with a good amount of summer irrigation it makes it through the summer quite well. So while I would not want to start one off without any shade, over time they adapt to deal with the summer sun pretty well.

Supplemental irrigation: When well established these plants can take a serious amount of water. Mine is planted near the house so it gets a good amount of run-off from the roof when it rains, and while I initially was concerned about getting it too wet (having lost an A. dichotoma, one of its parents, to too much moisture), the enormous growth spurts it puts on right after we get some good rain suggest that I could water it more than I do. Depending on rain, I water it about once a month in the non-summer months and once a week during the hot summer months (late May to late September).

Cold hardiness: I must say that the given hardiness of zone 8b seems optimistic to me. My plant got pretty serious leaf damage from a significant (for our area) cold spell with 3 nights in the low-mid 20s in early 2013. It survived, but it definitely took a while to grow out of those ugly damaged leaves. So while it might survive down to 8b, I would expect serious damage to the plant when T's hit the low 20s. It has withstood high 20s to low 30s just fine.

Photos to follow soon.