Opuntia trichophora - like many of the Opuntias - represents something of a challenge for taxonomy-minded botanists. On the Plant List it is considered a synonym of Opuntia polyacantha, a taxon with an enormous geographical range from Canada down to Mexico and from California through to the Midwest. However, on the authoritative Opuntiads.com website it is treated as a separate species and notes that Opuntia trichophora has a different ploidy to Opuntia polyacantha: it is diploid while Opuntia polycantha is tetraploid. For those curious to find out more about the taxonomical twists and turns of this taxon you could do worse than going to the Opuntiads website and exploring further. On the basis that more differentiation is better than less, I have always tended to be a 'splitter' rather than a 'lumper' and accordingly am treating it here as a separate species.

It is a tough hardy Opuntia growing at high latitude as far north as Wyoming and at high altitude at elevations from 3000ft to at least 7000ft above sea level. It is a low-growing Prickly Pear with a sprawling habit; the new cladodes usually grow upright and then becoming prostrate as further new growth weighs them down. It has long slender white spines that look harmless enough compared to many a cactus but when you touch them you discover they are barbed and overstay their welcome. But that's hardly the kind of thing that would put someone like you off such a lovely addition to your collection.