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
Mart.) from the high region of the Volcán Tacaná, Chiapas. The new variety appears to be much more extended in Mexico than the species itself. Abies lowiana (Gord.) A. Murr., a species not consistently recognised by botanists and mistakenly, often included in A. concolor (A. c. var. lowiana (Gord.) Lemm.) is reported here from "south of the Rio Grande", north of the town of Madera, Chihuahua. With its A. grandis (Dougl. ex D. Don) Lindl.-like pectinate arrangement of the leaves on shade branches (Figs 27-28) and young trees, a character that never appears in A. concolor, A. lowiana is more related to the previous species than to A. concolor in a strict sense. It is important to distinguish this species from the latter taxon, which is fairly frequent in the northwestern region of Mexico. Found here with surprisingly lustrous green foliage (always pruinose grey in the north), it is considered a new variety of A. lowiana. DESCRIPTIONS 1. Abies hidalgensis Debreczy, Rácz, et Guízar 1 , Figure 1 : c l-c3; Plate I: I in Phytologia (April 1995) 78(4): 217-243; "Abies A" in NewsBrief (IDRI) No. 6 (Sep. 1994); Figs 2, 9-10) in the present article. - TYPUS: Mexico, eastern Hidalgo: 4-5 km north of Metepec, 2,300 m, June 12, 1994. Debreczy, Rácz, Biró et al. #40323 (Holotypus: BP; Isotypi: A, CHAP, E, MEXU, NA). Arbor ad 18 m alta, trunco simplici; habitus columnari-conicus; cortex rasilis, in arboribus juvenilibus pallide cinereus, postea in laminas irreguläres magnas ruptus, in arboribus vetustis valde crassus et suberosus, pars interior corticis sanguinea; rami fusci, vel cinereo-fusci, usque ad 5-6 annos pilosi; ramuli validi, rasiles, pilis 0.2-0.3 mm longis, densis, flavo-brunneolis diaphanis cooperti; gemmae (partim foliis brevibus, incurvatis, terminalibus occultae) rotundato-desectae, tenuiter resinosae, squamis usque ad 15 triangularibus vel saltern apicibus squamorum tectae; folia pectinatim dislributa, (l-)3-5(-6) cm longa, abrupte abbreviata (usque ad 1 cm longa) in ramulis externis leviter deorsum et/vel versus apicem ramulorum inclinata, aciebus parallelis, apicibus rotundata et breviter (0.2-0.4 mm), sed conspicue emarginata vel subtiliter bifida, in positione umbrosa mollia flexibilia vel in acumine arboris aliquantum quasi succulenta; pagina dorsalis eorum atroviridis vel glauco-viridis, lineis stomatum usque ad 14, in ramulis ad lucem expositis deorsum medium folii attingentibus, sed in positione umbrosa plerumque 6 lineis brevibus, ad apicem folii litteram "V" formantibus; pagina ventralis argenteo-cinerea cum margine angusto (0.2 mm), viridi et costa media 0.2-0.4 mm lata, saepe cum lineis stomatum infractis; limitibus lateralibus bilateraliter singulis argenteis, lineis stomatum typice 14-15 (in positione umbrosa in foliis angustis 5-6) instructis; lineis stomatum cum stomatibus 9 pro 1 mm; stomata 0.06 mm longa, elongato-ovata, intense pruinosa; folia ramulorum infernorum in sectione transversali plano-triangularia, sed ramulorum fertilium triangularia cum canalibus resiniferis median is usque ad 7(!); strobili feminei 1 M. C. Guízar N. Enrique, Div. de Ciencias Forestales, Universidad Autonoma Chapingo, Mexico.
