I like the word seminal. It derives from the Latin word for seed, and it suggests things that have the capacity to generate. There are two main types of plant propagation: clonal (via cuttings, for instance, where the new plant is genetically identical to the parent) and by seed, where the new plant is similar to, but will slightly vary from, its parent or parents. It's this generation of new things that are similar to, yet different from, their ancestor (and given time and many generations, potentially very different from their ancestor) that makes reproduction by seed so exciting, and that in turn makes the word "seminal" so apt for descriptions of cultural phenomena that engender new, different, but related cultural phenomena.
The Latin word for seed from which seminal derives is semen. It's the same word we use for male animals' sex cells, and for this reason, there's been a kind of quailing at using the word "seminal" in public, as if we're reinscribing the illegitimate authority of male sexuality or the notion that men are more culturally generative than women. That is perhaps what we are doing, if when we hear the word semen in seminal, we think only of the sex cells that issue from testicles.
But rather than losing the beautiful metaphor embedded in seminal, a metaphor that suggests that words and stories scatter seeds that germinate into new and different words and stories, perhaps we should interrogate our use of the word semen (seed) to describe male sex cells.
A seed is what comes about when a plant's ovum and pollen fertilise each other. It already contains all the genetic material necessary to produce a new organism. A seed is necessarily already fertilised. Animal semen, on the other hand, is not sufficient to produce a new organism. If we draw an analogy between animal and plant reproductive elements (as we already do with the word semen), then the male sex cell would be better called pollen, and the fertilised ovum could be called the semen.
I guess this ain't going to happen, so in the meantime, perhaps we might take to calling our generative texts plain old seedy.