B. Papp szerk.: Studia Botanica Hungarica 34. 2003 (Budapest, 2003)

Debreczy, Zsolt; Rácz, István: A re-assessment of the new taxa of firs (Abies Mill.) reported from Mexico in 1995

Named after the central Mexican state of Hidalgo where the species was found. The name also recalls Miquel Hidalgo y Costilla (1762-1811), a prominent personality of the post-Columbian Mexican independence movement, after whom the state itself was named. Discussion: this rare and distinct tree with 5-7 resin canals in the needles and green cones with short, enclosed bracts was found in the state of Hidalgo in an area where (in the wider region) only Abies religiosa (H., B. et K.) Schlecht, et Cham, was known. The latter is completely different with its strongly curved, pointed (not bifid) leaves with two resin canals (not up to 7) and 2-3 times larger cones with long exserted, recurved bracts of prominent tip. Abies guatemalensis Rehd., a southern species with (typically) "bractless" cones, not known as far north as Hidalgo, has twice as many leaves on an equal length of (shade) branchlet with straight needles curving to almost a right angle from the stem (not curved, directed forward), with two resin canals (not up to 7). In A. guatemalensis the cones are typically pruinose blue (not pruinose green changing to light brown), have wide cyathiform "wing shaped" (not flabellate) cone scales with elongated (not short) basal section and slightly enclosed or finely exserted (not short, sessile) bracts with finely protruding (not absent) tip. Other species such as A. vejarii Mart, of northeastern Mexico (with short, curved, succulent needles with two resin canals, close to or exserted bracts) are too distinct even to be compared with the new species. Discovery: the species was found in a deep canyon running eastward, a few miles above the small village of Metepec (Fig. 10). The first tree was seen on April 3, 1994 on the upper rim of the canyon near a sharp turn downward toward Poza Rica and Tampico at an elevation of 2,350 m. The tree, old and struggling with only a few upper branches alive, had no cones or cone axils, but the distinct foliage and bark immediately suggested that it does not belong to any species known. In this extremely cloudy area we had no opportunity to continue the exploration at that time. Sterile branches were transferred to the Division de Ciencias Forestalls, Universidad Autónoma Chapingo (DCF/UACH) to preserve the (possibly sole) tree under #38672. We returned to the area on June 12. This time we saw more trees deep in the valley along with old cypress trees (Cupressus lusitanica Mill.). In spite of an early start, we had only a few minutes before the clouds filtered up and hid the valley. Realising the difficulty of reaching the trees from our position and having no evidence of cones, we went to the section of the canyon where the lone tree was found a few months earlier. We had good fortune for a few seconds and located a tree on a nearly vertical slope, 20 m above the right side of the river. The tree has had many cones, which were not ripe yet but seemed to be fully developed in size. Soon we found it to be identical to our #38672, but it was much younger with different bark