We cannot meaningfully understand why Petrosaviaceae and Triuridaceae lack vessels throughout the plant until we realize that the two families have probably lost vessels independently in response to the heteromycotrophic habit.
Also notable in this regard are families which are heteromycotrophic, such as Petrosaviaceae, Triuridaceae, and achlorophyllous Burmanniaceae and Orchidaceae (Carlquist, 1975; Wagner, 1977).
Velloziaceae (vessels with simple perforation plates in roots) plus Triuridaceae (a vesselless heteromycotroph) bear a sister relationship to the remaining Pandanales (Fig.
Kupea martinetugei, a new genus and species of Triuridaceae from western Cameroon.
Triuridaceae fossil flowers from the Upper Cretaceous of New Jersey.
Monocot pseudanthia revisited: floral structure of the mycoheterotrophic family Triuridaceae.