Cypselae are a type of fruits where the fruit is dry and just barely bigger than the seed. As they don't have any juice, they are never eaten as a fruit culinarily.
They are very, very similar to achenes, as they are both dry, indehiscent fruits with a single seed linked to the fruit wall only by the funicle. However cypselae derive from the superior ovaries, and achenes instead originate from inferior ovaries.