Pinus stormiae

(Martínez) Frankis 2024

Common names

Pino real, pino blanco [Spanish] (Perry 1991).

Taxonomic notes

Syn.: Pinus arizonica var. stormiae Martínez 1945 (basionym); Pinus ponderosa D. Douglas ex P. Lawson var. stormiae (Martínez) Silba 1990. See Pinus ponderosa for general taxonomic discussion. Several molecular studies, most notably Willyard et al. (2021a, 2021b), clearly established that this taxon warrants treatment at species rank, which it received in 2024. It occurs in a subclade of subsection Ponderosae, sister to P. brachyptera and P. scopulorum.

Description

Trees to 35 m tall with a straight, massive trunk up to 120 cm in diameter. Crown open, pyramidal in young trees, becaming round-topped; branches thick and spreading, the first-order branches drooping and the others ascending. Bark on young trees dark brown, rough and scaly, with age becoming 4-5 cm thick, deeply furrowed, divided into large irregular plates separating into thin closely appressed light cinnamon-brown scales. Twigs first orange-brown, pruinose, later turning dark gray-brown, with decurrent leaf bract scales. Needles tufted at the ends of the branches, in fascicles of 3-4(-5) needles, 14-25 cm long, 1.4-1.8 mm thick, rigid, dark green, with 8-12 lines of stomata on the abaxial (outer) side; margins finely serrate; resin canals 6-10, medial, and with two distinct vascular bundles; fascicle sheaths brown, persistent, initially to 30 mm long but wearing shorter, turning dark gray; needles falling after 2-3 seasons. Cotyledons 7-9. Seed cones ovoid to conical, symmetrical, 6-9 cm long, borne in groups of 1-3 on short, stout peduncles, light red-brown at maturity, with hard, stiff scales 12-14 mm wide, the apex margin rounded and smoothed with apophyses raised and with a transverse keel; armed with slender recurved spines. Cones open at maturity and are soon deciduous, leaving the peduncle and a few basal cone scales attached to the branchlet. Pollen cones borne in dense clusters at the ends of new shoots, 15-20×5 mm, yellow to yellow-brown. Seeds dark brown, 6 mm long, oval, slightly compressed towards the apex, with a thick coat; seed wings articulate, 20-25×8-9 mm, with about 28,000 seeds/kg. Wood light, soft, brittle, light red or yellow, with thick pale yellow or white sapwood (Sargent 1922, Perry 1991, Farjon and Styles 1997).

Distribution and Ecology

Mexico: Coahuila, Nuevo León, southwest Tamaulipas (Miquihuana) and parts of San Luis Potosí (Perry 1991); United States: Texas (Perry 1991, Willyard et al. 2021a). It is probably most abundant in southern Nuevo León. Occurs at 1,500-3,000 m elevation, commonly with Quercus, Juniperus, or other pines, particularly P. cembroides and P. pseudostrobus (Farjon and Styles 1997). In Nuevo León I observed that on gypsum-derived soils in was the only tree (photo at right), whereas adjacent carbonate substrates were dominated by P. cembroides but supported a variety of conifers, including P. stormiae.

Distribution data. Red indicates observations of Pinus arizonica sensu latu, which may include some observations of P. cooperi and P. stormiae. P. arizonica is shown in orange, P. stormiae in blue, and P. cooperi in yellow. Data sources include my observations, Farjon & Styles (1997), and downloads from GBIF (2014) and SEINet (2014).

This species has an ecological continuity with P. scopulorum, which seems not to have been investigated. Both are species of semiarid areas on the eastern margin of the cordillera, in areas with a summer precipitation maximum. Both are scrubby pines with relatively short, stiff needles (for subsection Ponderosae) and smallish, spiny cones. The difference is one of temperature, with P. scopulorum in a continental, cold-temperate regime and P. stormiae in a more maritime, warm-temperate to substropical regime. This continuity, would predict introgression and intermediate morphology an the trees of southern New Mexico and west Texas, where the species' ranges are contiguous.

Remarkable Specimens

Ethnobotany

Observations

Have seen it in the Sierra Peña Nevada of southern Nuevo León, and in extensive stands on the plains south of and at mid-elevations on Cerro Potosí, also in Nuevo León. Within its range it is a common and conspicuous pine.

Remarks

The epithet honors Marian Isabel Storm (1892-1975), an American writer and botanist who emigrated to Mexico in the 1930s. Along with Pinus douglasiana, this makes two independent American women that Martínez honored by naming pines for them.

This species is one of many principal hosts for the dwarf mistletoe Arceuthobium vaginatum subsp. vaginatum, and is also a principal host for A. vaginatum subsp. cryptopodum (Hawksworth and Wiens 1996).

Citations

Frankis, Michael. 2024. An overlooked name and new combinations in Pinus. IDS Yearbook 2023, p. 43.

Martínez, Maximino. 1945. Las Pinaceas Mexicanas. Tom. 16, Anales Inst. Biol. Univ. Nac. México (p. 284).

Willyard, Ann, David S. Gernandt, Blake Cooper, Connor Douglas, Kristen Finch, Hassan Karemera, Erik Lindberg, Stephen K. Langer, Julia Lefler, Paula Marquardt, Dakota L. Pouncey, and Frank Telewski. 2021a. Phylogenomics in the hard pines (Pinus subsection Ponderosae; Pinaceae) confirms paraphyly in Pinus ponderosa, and places Pinus jeffreyi with the California big cone pines. Systematic Botany 46:538–561.

Willyard, A., Gernandt, D.S., López-Reyes, A., and Potter, K.M. 2021b. Mitochondrial phylogeography of the ponderosa pines: widespread gene capture, interspecific sharing, and two unique lineages. Tree Genetics & Genomes 17(6):47. doi:10.1007/s11295-021-01529-4.

See also

The species account at Threatened Conifers of the World.