Espostoa lanata is the type species of the genus Espostoa, first designated by Britton and Rose in 1920 and named for Nicolas Esposto, a botanist at the School of Agriculture in Lima, Peru. This plant had previously been described as Cactus (1823) and then Cereus, Pilocereus, Cleistocactus and Oreocereus so it took nearly 100 years for it to achieve the name by which we know it today! Also, whilst Humboldt found it at what became its type locality in Ecuador, today this is at Huancabamba in Peru – its location didn't move, it was the border with Ecuador that was moved northwards! Enthusiasts, in general, don't tend to grow Espostoa, for they think of them as tall columnar plants unsuitable for the greenhouse, which is a pity. In practice, they can be the most rewarding of plants – slow growing, exhibiting neat bodies and fine spination, and often doing well in the Cereus classes at shows.
Espostoa lanata itself can reach up to 7m in height in habitat but, even bedded out in a greenhouse, it may only grow 10cm in a good year. In a pot it is even slower, but it is important to keep it growing, potting on frequently and watering well in the summer months. Plenty of light will ensure the wool and spination grow strongly and I regularly spray my specimens with water too during the growing season. It probably needs to be more than 2m tall before a side cephalium (and then flowers) will form, so it is the attractive body which will appeal to you first rather than the flowers.
There are several subspecies of Espostoa lanata (lanata, huanucoensis, lanianuligera and ruficeps) as well as some older 'varieties' which have since been subsumed – they are all worth growing if you can track them down and if you have room. I'll illustrate these different forms with two plants from my collection. First is a plant I acquired as a seedling in 2001 as Espostoa lanata var. sericata (fig. 1) – it is now just 60cm tall, still in a 12cm pot, but desperate for moving on. This is a tidy plant with short wool and very short, central spines. In complete contrast is this plant of Espostoa lanata subsp. lanata (E. ritteri) (fig. 2) which has quite striking central spines about 5cm long – this plant was grown from seed in 1998 and is now about 50cm tall.
In conclusion, if you see any small plants of the genus Espostoa for sale that take your fancy, it is well worth acquiring them – in (many) years to come, you will not be disappointed!