Evergreen perennial of the Saxifragaceae family, this cultivar belongs to the Prichard's Monument group, a set of complex hybrids from the Porphyrion section grouped under the botanical name × megaseiflora. These hybrids involve several alpine species, including Saxifraga burseriana and Saxifraga media, and were primarily developed in the 20th century within British and Central European horticultural circles. The cultivar is named after Karel Čapek, the Czech writer famous for introducing the word "robot" into the global vocabulary, suggesting a Czech or Central European horticultural origin, although precise details about the breeder are not available in the consulted sources.
The plant forms a very compact cushion of small dense rosettes, with short, rigid, and pointed leaves, dark green with glaucous reflections, strongly calciferous on the margins, giving them a characteristic grayish appearance. The habit is particularly tight and architectural, even when not in bloom.
The flowers are remarkably large relative to the size of the cushion, medium pink to pale pink with a more intense center, bright red at the anther, borne on very short stems. They open directly at the foliage level, giving the plant in bloom a dense and generous appearance. In cultivation, flowering generally occurs from February to April.
Like all hybrids of this demanding group, 'Karel Čapek' is preferably grown in a pot or container under cold shelter, in a very well-drained and limestone substrate, protected from prolonged winter rains.