Xylorrhiza

Xylorrhiza

North American plant genus in the family Asteraceae. All of its members are selenium indicators and usually contain sufficient selenium, in the form of selenocompounds, to cause poisoning manifested by alopecia, lameness, laminitis, hoof deformity.
The recorded species are X. glabriuscula, X. parryi, X. tortifolia, X. venusta, X. villosa. All called also woody aster. Formerly classified in genus Aster.
References in periodicals archive ?
On the other hand, while selenium is accumulated by asters, Machaeranthera, Atriplex, Oonopsis and some species of Astragalus (milkvetch), there are some plants which are obligated to accumulate it -- they need it: Stanleya (Princesplume), Xylorrhiza (woody aster) and Astragalus mollissimun (locoweed).
A similar disjunction is represented by Scrophularia xylorrhiza, a perennial chasmophyte with a lignified basis, which grows in cliffy section of habitat 2 below peak l [ILLUSTRATION FOR FIGURES 23 & 24 OMITTED] and in the cliffs of Arbel, by the Sea of Galilee north of Tiberia, 265 km north of Nahal Elot.