Tuesday, December 12, 2017

[Botany • 2017] Pinus vallartensis • A New Species (Pinaceae) from western Jalisco, Mexico


Pinus vallartensis Pérez de la Rosa & Gernandt

 Pérez de la Rosa & Gernandt. 2017
Illustration by G. Rodríguez  DOI:  10.11646/phytotaxa.331.2.7 

Abstract

We propose and describe Pinus vallartensis Pérez de la Rosa & Gernandt as a new species from western Jalisco, Mexico. The pine occurs near the southern limit of the Sierra Occidental at the intersection of the municipalities of Puerto Vallarta, Cabo Corrientes, and Talpa de Allende. Pinus oocarpa occurs within the margins of this forest to the south and P. jaliscana to the west. The more distantly related pine, P. maximinoi, also occurs in the area. Pinus vallartensis is like P. jaliscana and P. oocarpa in possessing leaf resin canals in a septal condition and serotinous seed cones on slender peduncles. It is distinguished mainly by its small seed cones and lax foliage. This discovery highlights the exceptional diversity of pines in Mexico and the state of Jalisco.

Keywords: Gymnosperms, pine, Oocarpa Group, septal, ovoid cones


FIGURE 1. Pinus vallartensis sp. nov., A, seed cone, B, leaves, C, branch with leaves and pollen cones D, lateral view of cone scale, E, abaxial view of cone scale, F, adaxial view of cone scale, G, seeds with articulate wings.

 (Illustration by Gretchen Rodríguez, from J. A. Pérez de la Rosa & D. Gernandt 2134 in MEXU).

Pinus vallartensis Pérez de la Rosa & Gernandt, sp. nov. 

Type:—MEXICO. Jalisco: municipio de Puerto Vallarta, 100 m al sur de “Las Juntas” (arroyos Palo María y Chupalodo), elevation 423 m, 17 September 2016, J.A. Pérez de la Rosa & D. Gernandt 2134 (holotype: IBUG!; isotype MEXU!).


Diagnosis:— Similar to Pinus oocarpa and P. jaliscana, differing in its lax leaves and smaller seed cones that range in length from (2.2–)2.5–3(–4.0) cm.

Distribution:— To date, no hard pine (subgenus Pinus) with a more restricted population has been found in the state of Jalisco. The species is almost exclusive to the southern part of the municipality of Puerto Vallarta (Fig. 2). The populations are reached by ascending paths, and have a north-south and east-west exposure. At its southern limit the species enters the municipalities of Cabo Corrientes and Talpa de Allende, ... at elevations of 380–1347 m a.s.l.

Etymology:— The name of this pine is in honor of the municipality of Puerto Vallarta, where the main part of the population of this species is found. It seems to be the only pine that occurs in this municipality.

FIGURE 3. Photographs of three pines from the Oocarpa group with septal resin canals,
A, Pinus jaliscana seed cone (J.A. Pérez de la Rosa 1841), B, Pinus oocarpa seed cone (D.S. Gernandt 560), C, Pinus vallartensis seed cone (J.A. Pérez de la Rosa s.n.), D, Pinus jaliscana seed (J.A. Pérez de la Rosa 1841), E, Pinus oocarpa seed (D.S. Gernandt 560), F, Pinus vallartensis seed (J.A. Pérez de la Rosa s.n.). Bar = 1 cm. (Photos by D.S. Gernandt).


Jorge Pérez de la Rosa and David S. Gernandt. 2017. Pinus vallartensis (Pinaceae), A New Species from western Jalisco, Mexico. Phytotaxa.  331(2); 233–242.  DOI:  10.11646/phytotaxa.331.2.7
  

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