Agastache mearnsii (Willd.) Woot. & Standl.
Description: An herb differing from other Agastache by having attenuate
calyx teeth 1/4 the total length of the calyx or more, herbaceous
stems, a calyx tube that is straight or nearly so and 2-4 mm in
diameter when pressed, with straight and conspicuous costae.
Distribution: Apparently bicentric, but apparently restricted
to Mexico, occurring in west-central Chihuahua and adjacent Sonora,
and in extreme northwestern Chihuahua.
Plants Seen or Cited: Chihuahua, extreme NW corner, in
N end of San Luis Mts., ca. 2 air mi. S of US border, W slope
of mts., in canyon at end of ranch road, 9 Oct 1982, Spellenberg
& Soreng 6818 (MEXU, NMC); A. mearnsii subsp. pallidiflora: New Mexico, Hidalgo
Co., Animas Mts. Sanders (1948, 1949) both TEX (cited in
Habitat: Dry canyon bottom with heavy Quercus rugosa,
Cupressus, Fraxinus overstory (Spellenberg & Soreng
6818); wooded steep slopes in humus in oak woodlands or in
the transitional zone with forest of Pinus ponderosa, 1,700-2,500
m. (Sanders 1987).
Discussion: Martin and Hutchins (1981) record the species
from the southwestern portion of New Mexico, mapping it in Grant
and Hidalgo counties. This may have derived from Wooton and Standley
(1915), the authors of A. mearnsii, who understood the
range to include the San Luis Mountains, the Animas Valley, the
Burro Mountains, and the Pinos Altos Mountains. Kearney and
Peebles (1961) do not note the species for Arizona. Sanders (1987)
has no citations for the species from New Mexico that are not
intergradient. His maps show the species to be strongly bicentric
in Sonora and Chihuahua, Fig. 82 showing the species to barely
cross into New Mexico, Fig. 90 showing the species to stop at
the international boundary. The only specimen of the species
at CIIDIR, NMC, UNM or UTEP is from 2 mi. S of the international
boundary in northwestern Chihuahua. Sanders maps a single site
from the Animas Mts. in Hidalgo County from which a collection was
made that is intergradient between A. mearnsii and A.
pallidiflora (Heller) Rydb. Sanders makes no note as to rarity,
noting that the species is "scattered on wooded steep slopes."
This species is not known in New Mexico in pure form; it is peripheral
from the Sierra Madre Occidental where its rarity cannot be determined
from available literature or specimens.
Kearney, T.H., and R.H. Peebles. 1969. Arizona Flora, 2nd
ed. (with supplement by J.T. Howell, Elizabeth McClintock, et
al.). Univ. California Press, Berkeley. 1085 pp.
Martin, W.C., and C.R. Hutchins. 1981. A Flora of New Mexico,
vol. 2. J. Cramer, Vaduz. Pp. 1277-2591.
Sanders, R.W. 1987. Taxonomy of Agastache section Brittonastrum
(Lamiaceae-Nepeteae). Systematic Botany Monographs 15:1-92.
Wooton, E.O, and P.C. Standley. 1915. Flora of New Mexico.
Contr. U.S. Natl. Herbarium 19: 1-794.
Information Compilied By: Richard Spellenberg 1998