Change in Status of Pinus cembroides Subsp. orizabensis (Pinaceae) from Central Mexico

Abstract

The Orizaba pinyon (Pinus cembroides subsp. orizabensis) is raised to specific status. Pinus orizabensis differs from P. cembroides in many characters, including needle and bark morphology and terpene chemistry. Orizaba pinyon, Pinus cembroides Zucc. subsp. orizabensis D. K. Bailey, is a local taxon of east central Mexico described by Bailey (1983). The taxon is here raised to specific rank because of marked differences in needle and bark morphology and terpene chemistry between it and P. cembroides. Pinus orizabensis (D. K. Bailey) D. K. Bailey & Hawksworth, comb. et stat. nov. Basionym: Pinus cembroides Zucc. subsp. orizabensis D. K. Bailey, Phytologia 54: 89. 1983. TYPE: Mexico. Puebla: Mpio. Soltepec, ca. 10 km SW of San Salvador el Seco on Highway 140, 19?04'N, 97?42'W, 2,370 m, 1983, D. K. Bailey 83-01 (holotype, MEXU; isotypes, ARIZ, CHAPA, COLO, E, ENCB, INIF, K, MO, NY, RM, TEX, UC, US, UTC). Pinus cembroides, as interpreted by Bailey (1983) and Bailey & Hawksworth (1988), was considered to be comprised of three allopatric subspecies: 1. Subspecies cembroides, the most widespread taxon, ranging from northern Chihuahua and west Texas throughout the Sierra Madre Occidental and Sierra Madre Oriental to central Mexico (Hidalgo and northern Veracruz). 2. Subspecies lagunae (Robert-Passini) D. K. Bailey, a local endemic restricted to the Sierra Laguna in southern Baja California. 3. Subspecies orizabensis D. K. Bailey, a local endemic in Puebla, Tlaxcala, and Veracruz. Since that time there has been a trend to accept subspecies lagunae as a distinct species, Pinus lagunae M.-F. Passini (1987), e.g., in the recent compendium of the pines of Mexico and Central America (Perry, 1991). However, because the differences between subspecies cembroides and orizabensis are greater than those between subspecies cembroides and lagunae, we suggest raising subspecies orizabensis to species rank as well. Pinus orizabensis and P. cembroides are not sympatric, and the gap between them is about 140 km (Bailey, 1983). The two pines differ in several morphological, chemical, and ecological features (Bailey, 1983), some of which are listed in Table 1. Acknowledgment. We thank Teobaldo Eguiluz Piedra, Director, Centro de Genetica Forestal, Chapingo, Mexico, for encouraging us to make this new combination. TABLE 1. Comparisons of some characters of Pinus orizabensis and P. cembroides. Character P. orizabensis P. cembroides Needle number per fascicle Range 2-5; ca. 75-95% in 3's, Range 2-4; ca. 60% in 2's and 40% 5-20% in 4's in 3's Needle color Dorsal surface bluish-green; ventral Dorsal surface yellow-green; ventral surface markedly glaucous surface slightly glaucous Bark of mature trees Thin, little transverse fissuring, inner Thick, strong transverse fissuring, inbark conspicuous, orange ner bark inconspicuous, yellow Monoterpenes 3-carene usually less than 1% 3-carene usually ca. 10% Main elevational range 2,300-2,700 m 1,700-2,400 m NOVON 2: 306-307. 1992. This content downloaded from 157.55.39.132 on Thu, 15 Sep 2016 06:14:45 UTC All use subject to http://about.jstor.org/terms Volume 2, Number 4 1992 307 Bailey & Hawksworth Pinus cembroides subsp. orizabensis