We counted rotifers within lobules of an epiphytic liverwort (Frullania eboracensis subs. eboracensis). Of 81 plants marked in the summer of 2001, 44 were female, 17 male, and 20 nonexpressing. Nonexpressing plants were significantly smaller than expressing plants. An ANCOVA revealed a non-significant or marginally significant tendency for the proportion of rotifer-occupied lobules to differ among male, female, and nonexpressing plants (p ≤ 0.09). Nonexpressing plants tended to have the greatest proportion of occupied lobules. We hypothesized that nonexpressing plants were younger than expressing plants. We investigated this pattern further by sampling from the interior and the edges of plants, knowing that the exterior of the plant is younger than the interior. In two separate experiments on different plants, a significantly greater proportion of exterior than interior lobules contained rotifers