The total alignment of the 121 Tillandsioideae and 12 sequences outgroups (2 Bromelioideae, 8 Pitcairnioideae and 2 Rapateaceae) has produced a matrix of 5910 characters of which 5098 not informative.
Epidermal, spherical (druse-like) silica bodies, similar to those of Kingia and Baxteria (Rudall & Chase 1996), occur in some Poales (Bromeliaceae, Cyperaceae, Rapateaceae, Thurniaceae).
Globular, condensed inflorescences also occur in Eriocaulaceae, Sparganium, and Rapateaceae. In Rapateaceae, the number of bracts varies considerably between genera (Gleason 1923), as in Dasypogonaceae.
He also found a surprising lack of aluminum hyperaccumulators in the monocotyledons, exceptions being members of the Rapateaceae and Aletris (Liliaceae).
However, judging from the illustrations, this tissue is not a typical thick-walled hypostase (although it is adjacent to the antipodals), but an enlarged thin-walled region of the nucellus, possibly with a storage function, as in, e.g., Dasypogonaceae and Rapateaceae (see perisperm below).