Ostrya knowltonii Coville
Family: Betulaceae
Description: Relatively small trees to 10.0 m in height;
bark brownish gray, broken into narrow scales; twigs and leaf
petioles often cover with stalked glands (SE New Mexico); leaf
blades suborbicular-ovate to ovate-elliptic, rounded to slightly
cordate at base, margins sharply double-serrate, 3.0 to 5.5 cm
in length and 2.5 to 5.0 cm in width; pistillate catkins a flattened
bladder-like, papery husk; nutlets not winged, each enclosed in
the papery bractlets; perianth absent in the staminate flowers
and present in the pistillate flowers; staminate catkins 2.0 to
3.0 cm in length and pistillate catkins 1.0 to 4.5 cm (?) in length
at maturity.
Distribution: Has been rarely collected in the southern
one-third of New Mexico at 1,500-2,100 m (5,000-7,000 ft)
in elevation. It also occurs in Texas and Arizona. Known for its
extremely hard wood, it is usually found along streams and in
moist canyons.
Plants Seen or Cited: ARIZ: Several sheets, however all
are from the Grand Canyon area. NMSU: One collection, San Andres
Mountains, north side of San Andres Peak, T.K. Todson, 19 Oct. 1975
Comments: There are several unanswered basic questions
concerning speciation within the taxon in the southwest. Although
labeled a single species, I am not certain the Arizona collections
and the Texas collections should be considered a single species.
It seems to me we need to know more about the genus in Mexico,
in comparison to the genus in eastern U.S. We should protect
the genus Ostrya in New Mexico.
Status: Rare in NM and with considerable disjunction from
both the AZ and TX collections.
Important Literature:
Carter, J.L. 1997. Trees and shrubs of New Mexico.
Correll, D S. and M.C. Johnson. 1970. Manual of the vascular plants of Texas.
Editorial Committee. 1996. Flora of North America, Vol. 3.
Kearney, T.H. and R.H. Peebles. 1951. Arizona flora.
Martin, W.C. and C.R. Hutchins. 1980. A flora of New Mexico.
Powell, A.M. 1988. Trees and Shrubs of Trans-Pecos Texas.
Welsh, S.L., D. Atwood, S. Goodrich and L.C. Higgins. 1987. Great basin naturalist memoirs:
A Utah flora.
Information Compiled By: Jack Carter, 1997