One of the large tree aloes. This species forms a single trunk eventually reaching 10-15 feet tall, with a rosette of huge, toothed leaves to 3 feet across. In winter, a multi-branched, erect candelabra of flowers appears, which can be orange, scarlet, gold or even white. A spectacular specimen plant if you have the room.
Similar growth habit in every respect to A. ferox above, except that the inflorescence is horizontally branched instead of erect. The leaves also tend to be spinier than A. ferox, with fierce teeth all over the leaf surfaces as well as along the edges.
This species grows to around 18-24 inches across, almost always as a solitary rosette. Very fleshy, softly striped grey-green leaves have a thin red margin, hence the species name. Beautiful coral-orange flowers on a many-branched stalk can last up to three months in late winter. Widely available in the nursery trade, but buyer beware - there is a hybrid that I have seen being sold as the true species! The genuine article has no teeth along the leaf margins, and rarely (if ever) forms offsets. The hybrid is a tough and useful landscape plant, but it is NOT striata.
Aloe x. 'David Verity'
This hybrid of A. petricola and A. speciosa has spectacular two-toned flower spikes, with deep red buds opening to creamy white. This is a large clumping form, with12-18" rosettes eventually forming a colony 6 feet across or more.
A low clump-forming aloe to around 3 ft x 3 ft. With glossy, toothed leaves that turn a brilliant brick red in bright sunlight. It's not yet common in nurseries, but worth seeking out. Some clones seem to be much redder than others; try to find one with as much color in it as possible.
One of the most popular and common aloes, for good reason. It is easy, tough as nails, and adaptable to almost any condition. This species grows to a fairly large shrub over time, eventually reaching 8 ft. x 8 ft. Bright orange candelabras of flowers in winter last for at least two months. There is a cultivar with beautifully variegated leaves that is worth seeking out.