A revision of the Asian Pinus subsection Strobus (Pinaceae)
The Asian taxa of Pinus subsect. Strobus are revised, based on available type and other authentic material as well as on extensive field studies, including populations at the type localities. P. fenzeliana is neotypified and transferred to P. subsect. Flexiles. Statistical evaluation of ample material revealed that the original description of P. kwangtungensis is based on heterogeneous material, including a population from Hainan Island, which is here distinguished and described as the new species P. orthophylla. The continental P. kwangtungensis s. str., which is morphologically very close to P. wangii, is recognized as a subspecies of the latter, besides subsp. varifolia. An isolated population inN Vietnam, near the Laotian border, hitherto also considered to belong to P. kwangtungensis, is described as the new species P. eremitana. The Japanese P. parviflora, with two subspecies, is found to be closely related to P. wangii and P. eremitana. The imperfectly known Taiwanese P. uyematsui, mostly included in the other Taiwanese endemic P. morrisonicola, is maintained as a separate species similar to the Vietnamese P. dalatensis, and a hybrid between the two Taiwanese species is described as the nothospecies P. ×hayatana. The E Himalayan P. bhutanica is recognized as a subspecies of P. wallichiana.Akey to all members of P. subsect. Strobus, comprising nine Eurasian and six American species, and a revised classification of the Eurasian species in two series and three subseries, one series and two subseries here described as new, are provided.