Introductory
SPECIES: Pinus washoensis | Washoe Pine 



ABBREVIATION : 
PINWAS

SYNONYMS : 
NO-ENTRY


SCS PLANT CODE : 
   PIWA


COMMON NAMES : 
   Washoe pine
   yellow pine


TAXONOMY : 
The currently accepted scientific name of Washoe pine is Pinus
washoensis Mason and Stockw. [3,8,9].  There are no recognized
subspecies, varieties, or forms.  

Washoe pine origins are uncertain.  Haller [29] proposed that Washoe
pine resulted from hybridization between either Pacific ponderosa pine
(P. ponderosa var. ponderosa) and Jeffrey pine (P. jeffreyi) or Pacific
ponderosa pine and Rocky Mountain ponderosa pine (P. ponderosa var.
scopulorum).  Mirov [30] dismissed Jeffrey pine as a possible ancestor
on chemical and morphological grounds, suggesting that Washoe pine is a
variety or mutant of ponderosa pine.  Critchfield [4] stated that Washoe
pine is a Pleistocene derivative of Rocky Mountain ponderosa pine.
Washoe pine sets more sound seed per cone in artificial crosses with
Rocky Mountain ponderosa pine than in natural intraspecific crosses.
This rare instance of heterosis for seed set in interspecific conifer
hybrids establishes a strong and direct evolutionary relationship
between Washoe pine and the Rocky Mountain ponderosa pine [17].

Washoe pine hybridizes with Pacific ponderosa pine [17,26] and rarely
with Jeffrey pine [4].



LIFE FORM : 
Tree

FEDERAL LEGAL STATUS : 
No special status

OTHER STATUS : 
NO-ENTRY


COMPILED BY AND DATE : 
Lora L. Esser, December 1993


LAST REVISED BY AND DATE : 
NO-ENTRY


AUTHORSHIP AND CITATION : 
Esser, Lora L. 1993. Pinus washoensis. In: Remainder of Citation

Related categories for Species: Pinus washoensis | Washoe Pine