not the flower sits on a pedicel, which determines the subgenus. (Any mature plant may be identified to this extent, even if it is not in bloom.) Identification proceeds based on flower parts, leaves, and other characteristics. A combination of characteristics is usually required to identify the plant. Identification of a non-flowering, non-fruiting plant with bare leaves may be difficult. Although some species of Trillium have petioles (leaf stalks) and/or distinctive leaf shapes, these features are seldom sufficient to identify the plant down to the species level. In eastern North America, jack-in-the-pulpit (Arisaema triphyllum) is often mistaken for bare-leaved Trillium. Both species are about the same height with trifoliate leaves but the former lacks 3-way rotational symmetry and has leaf veins unlike those of Trillium. Ecology Trilliums are myrmecochorous, that is, ants act as agents of seed dispersal. Each seed of a ripe fruit has a white fleshy appendage called an elaiosome. Ants are attracted to the elaiosome, so much so they often bore holes into the fruit instead of waiting for it to drop off on its own. The ants carry the seeds back to their nest where they eat the elaiosomes and discard the seeds. Here the seeds eventually germinate, an average of about 1 meter away from the parent plant. For example, the seeds of Trillium camschatcense and T. tschonoskii are collected by ant species Aphaenogaster smythiesi and Myrmica ruginodis. Sometimes beetles interfere with the dispersal process by eating the elaiosomes, which makes the seeds less attractive to ants. Yellow jackets (Vespula spp.) and other wasps are similarly attracted to elaiosomes. The wasps carry off the seeds and feed on the elaiosomes an average of about 1.4 meters away from the parent plant. Yellow jackets are documented seed dispersers for at least three species of Trillium (T. catesbaei, T. cuneatum, T. undulatum). Hybrids , Plants of the World Online recognizes five named hybrids, four in Asia and one in North America. Three of the Asian hybrids, , , and , are well studied, but little is known about the Asian hybrid . One of its parents is T. camschatcense but the other parent is unknown. The only named hybrid in North America is . As originally described, its parents are Trillium ovatum and Trillium rivale, but the latter species is now a member of genus Pseudotrillium, and so has become an intergeneric hybrid. In 1982, Haga and