List of Pinus species

(Redirected from Pinus subg. Pinus)

Pinus, the pines, is a genus of approximately 111 extant tree and shrub species. The genus is currently split into two subgenera: subgenus Pinus (hard pines), and subgenus Strobus (soft pines). Each of the subgenera have been further divided into sections based on chloroplast DNA sequencing[1] and whole plastid genomic analysis.[2] Older classifications split the genus into three subgenera – subgenus Pinus, subgenus Strobus, and subgenus Ducampopinus (pinyon, bristlecone and lacebark pines)[3] – based on cone, seed and leaf characteristics. DNA phylogeny has shown that species formerly in subgenus Ducampopinus are members of subgenus Strobus, so Ducampopinus is no longer used.[1]

Pinus
Subgenus Pinus
Section Trifoliae

Subsection Ponderosae

Subsection Contortae

Subsection Australes

Section Pinus

Subsection Pinus

Subsection Pinaster

Subgenus Strobus
Section Quinquefoliae

Subsection Gerardianae

Subsection Krempfianae

Subsection Strobus

Section Parrya

Subsection Nelsonianae

Subsection Balfourianae

Subsection Cembroides

The species of subgenus Ducampopinus were regarded as intermediate between the other two subgenera. In the modern classification, they are placed into subgenus Strobus, yet they did not fit entirely well in either so they were classified in a third subgenus. In 1888 the Californian botanist John Gill Lemmon placed them in subgenus Pinus. In general, this classification emphasized cone, cone scale, seed, and leaf fascicle and sheath morphology, and species in each subsection were usually recognizable by their general appearance. Pines with one fibrovascular bundle per leaf, (the former subgenera Strobus and Ducampopinus) were known as haploxylon pines, while pines with two fibrovascular bundles per leaf, (subgenus Pinus) were called diploxylon pines. Diploxylon pines tend to have harder timber and a larger amount of resin than the haploxylon pines. The current division into two subgenera (Pinus and Strobus) is supported with rigorous genetic evidence.

Several features are used to distinguish the subgenera, sections, and subsections of pines: the number of leaves (needles) per fascicle, whether the fascicle sheaths are deciduous or persistent, the number of fibrovascular bundles per needle (2 in Pinus or 1 in Strobus), the position of the resin ducts in the needles (internal or external), the presence or shape of the seed wings (absent, rudimentary, articulate, and adnate), and the position of the umbo (dorsal or terminal) and presence of a prickle on the scales of the seed cones.[4]

Both subgenera are thought to have a very ancient divergence from one another, having diverged during the late Jurassic.[5]

Subgenus Pinus Edit

Subgenus Pinus includes the yellow and hard pines. Pines in this subgenus have one to five needles per fascicle and two fibrovascular bundles per needle, and the fascicle sheaths are persistent, except in P. leiophylla and P. lumholtzii. Cone scales are thicker and more rigid than those of subgenus Strobus, and cones either open soon after they mature or are serotinous.[6]

Section PinusEdit

Section Pinus has two or three needles per fascicle. Cones of all species have thick scales, and all except those of P. pinea open at maturity. Species in this section are native to Europe, Asia, and the Mediterranean, except for P. resinosa in northeastern North America and P. tropicalis in western Cuba.[6]

Subsection Incertae sedis

Subsection PinusEdit

 
Pinus sylvestris

All but two species (P. resinosa and P. tropicalis) in Subsection Pinus are native to Eurasia.[6]

Subsection PinasterEdit

 
Pinus roxburghii

Subsection Pinaster contains species native to the Mediterranean, as well as P. roxburghii from the Himalayas. The scales of its cones lack spines.[4] It is named after P. pinaster.

Section TrifoliaeEdit

Section Trifoliae (American hard pines), despite its name (which means "three-leaved"), has two to five needles per fascicle, or rarely eight. The cones of most species open at maturity, but a few are serotinous. All but two American hard pines belong to this section.[6]

Phylogenetic analysis supports ancient divergences within this section, with subsections Australes and Ponderosae having diverged during the mid-Cretaceous.[5]

Subsection AustralesEdit

 
Pinus elliottii

Subsection Australes is native to North and Central America and islands in the Caribbean.[4][8][9]

 
Pinus muricata

The closed-cone (serotinous) species of California and Baja California, P. attenuata, P. muricata, and P. radiata, are sometimes placed in a separate subsection, Attenuatae.[10]

Subsection ContortaeEdit

Subsection Contortae is native to North America and Mexico.[4]

Subsection PonderosaeEdit

 
Pinus jeffreyi

Subsection Ponderosae is native to Central America, Mexico, the western United States, and southwestern Canada,[4][13] although its former range was possibly much wider as evidenced by upper Miocene fossils belonging to this subsection found in Japan [14]

Subgenus Strobus Edit

 
Pinus strobus

Subgenus Strobus includes the white and soft pines. Pines in this subgenus have one to five needles per fascicle and one fibrovascular bundle per needle, and the fascicle sheaths are deciduous, except in P. nelsonii, where they are persistent. Cone scales are thinner and more flexible than those of subgenus Pinus, except in some species like P. maximartinezii, and cones usually open soon after they mature.[6]

Section ParryaEdit

Section Parrya has one to five needles per fascicle. The seeds either have articulate (jointed) wings or no wings at all. In all species except for P. nelsonii, the fascicle sheaths curl back to form a rosette before falling away. The cones have thick scales and release the seeds at maturity. This section is native to the southwestern United States and Mexico.[6]

Subsection BalfourianaeEdit

Subsection Balfourianae (bristlecone pines) is native to southwest United States.

Subsection CembroidesEdit

 
Pinus cembroides

Subsection Cembroides (pinyons or piñons) is native to Mexico and the southwestern United States.

Subsection NelsonianaeEdit

Subsection Nelsonianae is native to northeastern Mexico. It consists of the single species with persistent fascicle sheaths.

Section QuinquefoliaeEdit

Section Quinquefoliae (white pines), as its name (which means "five-leaved") suggests, has five needles per fascicle except for P. krempfii, which has two, and P. gerardiana and P. bungeana, which have three. All species have cones with thin or thick scales that open at maturity or do not open at all; none are serotinous. Species in this section are found in Eurasia and North America, and one species, P. chiapensis reaches Guatemala.[15][16]

Subsection GerardianaeEdit

Subsection Gerardianae is native to East Asia. It has three or five needles per fascicle.

Subsection KrempfianaeEdit

Subsection Krempfianae Currently native to Vietnam, with a fossil record extending into the Oligocene. It has two needles per fascicle, and they are atypically flattened. The cone scales are thick and have no prickles. Until 2021, the subsection was considered monotypic, when an Oligocene fossil species was described from Yunnan Province, China.

Subsection StrobusEdit

 
Pinus cembra

Subsection Strobus has five needles per fascicle and thin cone scales with no prickles. Needles tend to be flexible and soft with slightly lighter side underneath.[18] It is native to North and Central America, Europe, and Asia.[4]

Incertae sedisEdit

Species which are not placed in a subgenus at this time.

See alsoEdit

ReferencesEdit

  1. ^ a b Gernandt et al. 2005.
  2. ^ Zeb et al. 2019.
  3. ^ Frankis, Michael (2002). "Classification of the genus Pinus". The Lovett Pinetum Charitable Foundation.
  4. ^ a b c d e f Gernandt et al. 2005, p. 35.
  5. ^ a b Stull, Gregory W.; Qu, Xiao-Jian; Parins-Fukuchi, Caroline; Yang, Ying-Ying; Yang, Jun-Bo; Yang, Zhi-Yun; Hu, Yi; Ma, Hong; Soltis, Pamela S.; Soltis, Douglas E.; Li, De-Zhu (July 19, 2021). "Gene duplications and phylogenomic conflict underlie major pulses of phenotypic evolution in gymnosperms". Nature Plants. 7 (8): 1015–1025. doi:10.1038/s41477-021-00964-4. ISSN 2055-0278. PMID 34282286. S2CID 236141481.
  6. ^ a b c d e f Gernandt et al. 2005, p. 38.
  7. ^ Stockey 1983.
  8. ^ "Pinus cubensis". Germplasm Resources Information Network (GRIN). Agricultural Research Service (ARS), United States Department of Agriculture (USDA).
  9. ^ "Pinus occidentalis". Germplasm Resources Information Network (GRIN). Agricultural Research Service (ARS), United States Department of Agriculture (USDA).
  10. ^ Earle, Christopher J., ed. (2018). "Pinus". The Gymnosperm Database.
  11. ^ Wehenkel, C.; Mariscal-Lucero, S.; González-Elizondo, M.S.; Aguirre-Galindo, V.A.; Fladung, M. & López-Sánchez, C.A. (2020). "Tall Pinus luzmariae trees with genes from P. herrerae". PeerJ. 8: e8648. doi:10.7717/peerj.8648. PMC 7049253. PMID 32149029.
  12. ^ McKown, Stockey & Schweger 2002.
  13. ^ "Pinus hartwegii". Germplasm Resources Information Network (GRIN). Agricultural Research Service (ARS), United States Department of Agriculture (USDA).
  14. ^ a b Yamada, Toshihiro; Yamada, Mariko; Tsukagoshi, Minoru (2015-12-16). "Taxonomic revision of Pinus fujiii (Yasui) Miki (Pinaceae) and its implications for the phytogeography of the Section Trifoliae in east Asia". PLOS ONE. 10 (12): e0143512. Bibcode:2015PLoSO..1043512Y. doi:10.1371/journal.pone.0143512. ISSN 1932-6203. PMC 4689564. PMID 26673795.
  15. ^ Gernandt et al. 2005, pp. 38–39.
  16. ^ "Pinus chiapensis". Germplasm Resources Information Network (GRIN). Agricultural Research Service (ARS), United States Department of Agriculture (USDA).
  17. ^ Zhang, Jian-Wei; Wang, Li; D'Rozario, Ashalata; Liang, Xiao-Qing; Huang, Jian; Zhou, Zhe-Kun (2021). "Pinus leptokrempfii, an Oligocene Relative of the Flat-Needled Pine PINUS krempfii (Pinaceae) from China: Implications for Paleogeographic Origin". International Journal of Plant Sciences. 182 (5): 389–400. doi:10.1086/713957. S2CID 233888471.
  18. ^ "Eastern white pine (Pinus strobus)". Minnesota Department of Natural Resources. St. Paul, Minnesota.

BibliographyEdit

External linksEdit