Why do some club moss species lack distinct strobili?

In many club moss species (family Lycopodiaceae), sporophylls—the leaves associated with spore-producing sporangia—are organized into specialized, compressed structures called strobili (or cones) at the tips of the branches.123

However, some species lack these distinct strobili because their sporophylls are not aggregated into a compact cone. Instead, these fertile, spore-bearing leaves are scattered along the stem, often resembling the vegetative leaves of the same plant. In these instances, the plant simply features alternating fertile and sterile regions along its branches rather than a terminal cone. Examples of species that lack distinct strobili include the shining club moss (Huperzia lucidula) and the fir club moss (H. selago), which bear their spore capsules at the bases of leaves distributed along their branches.132