Hanging aloes are adapted to a pensile life. These aloes are growing suspended as a rule and not because the seeds got stuck on a ledge. Many aloe species grow well on mountain slopes. As long as they have some grip in the soil they are happy, but that does not make them hanging or pensile aloes.

Aloe ferox just loves slopes. I doubt if anybody would think they are hanging. Just wanted to add the pretty scene.

Aloe dewinterii grows in the north west of Namibia on the steep dolomite slopes and high cliffs. On the cool side of a cliff is better than in the open sun but it can grow just as well on the ground usually on or under a dolomite rock.This plant has large leaves. The very soft pastel colors seem to be the rule in the Namibian aloes and the pale blue-green tinted with pink rosette is beautiful in the green garden . Next to the aloe is a dry bush, it is not old flower stalks.

Aloe comptoni growing in the Small Karoo. It also grows well on the mountain cliffs. On the ground it will grow creeping along with the upper part of the stem and rosette straight up and the old growth lying flat, later dying off. It looks better on a cliff. I would like to call it a hanging aloe but as it grows just as well on the flat ground it will not quite qualify.

At last. Aloe hardyi is a cliff hanger growing close against the cliff. The obvious way that it hugs the stone or edge over which it grows gives a lovely display in the garden over a wall. The flower stalk growing from the plant in the middle is visible on the photo. The inflorescens grows a little way horizontal and then it turns upwards. The thick aloe leaves are stiff. Pull out the plant where it is growing and the rosette with the leaves remain in the bended shape it had fitting over the stone. New leaves will adjust shape..
Aloe hardyi blooms in winter.

Another pending aloe named Aloe pendens from Yemen. It has a relative thin stalk by which it hangs down, but the rosette face horizontally and away from the cliff. The thick stiff leaves grow in the half circular shape, it is not soft and hanging down. Turn the plant upside down and it will look the same as when you turn the photo. (You will have to take my word as there is no way that I will uproot it to show my point.) The flower stalk grows a little way away from the
plant and then it turns upwards. The small flowers are pretty, shading red with green tips. Buds are not open yet on the photo below. Aloe pendens blooms every 5-6 months.

Aloe hardyii (from the northern parts of the Republic of South Africa) and Aloe pendens (from Yemen) can not really grow comfortable on flat ground. They probably would survive, anything is better than dying, but what will they look like bending and growing over each other?

The relative small grass-like Aloe ballii from Zimbabwe also grows hanging from cliffs. It is a very pretty aloe for a hanging basket. It grows fast and easy and blooms throughout the year. It would not fare too bad growing on flat ground except for the flower. The flower stalk is a thin soft thread hanging down and that would not function on flat ground. On the photo is an inset of the pretty flowersand on closer look you can see the flowers
PS. I have only one plant,  no seeds.

I built this wall for my pending aloes.
Aloe ballii is hanging on a branch to the right top in a basket . . Aloe hardyii is to the right on the wall and Aloe pendens (plant colour very much like the background) is in the middle. There are a few smaller aloe types on the top of the wall and some other succulent plants. The wall is very narrow and takes up little space but a lot can be planted on it. (flowers would be pretty too).