Quercus garryana varieties

The identification of the sub taxonomic identity of Quercus garryana is not without some risk of a misapplication. An assured identification requires observation of a number of morphological details. Additionally, the key features are variable over the course of a season, thus, spring and fall features present different appearances. Two diagnostic keys are aviable, the Jepson and the Flora of North America keys. These are similar but contain subtle descriptive narratives. Both keys split the taxa based on habit type of a single trunk or as shrubs or small trees.

The Jepson Quercus garryana eflora key to the varieties identifies var. garryana as a tree with large fusiform pubescent buds and with var. breweri and semota as scrub or shrubs with small red or brown buds. These are then separated by the abaxial leaves' stellate hair. The The Flora of North America key allows for separation based on the twig and bud pubescence. Thus, the keys should be interpreted as a choice between two combinations of features; tree and bud structure and pubesence, or scrub-shrub and twig and bud structure and pubesence. However, the plant structure is ambiguous as Q. g. var. garryana presents as tree, scrub, and shrub. The stature of Q. garryana is a function of climate and fire history, as the taxon is found as single stem stately trees and in the form of scrub-shrub thickets. High elevation oak in the Oregon Cascades is mostly that of a shrub structure. Fire also has a impact of the structure of the habit. The high elevation Q. garryana observations appear to be low and tall shrubs. This most likely is the result of fire and growing season. The ambiguity of habit can lead to a misapplication, therefore, the key should be reconsidered to consider the features of the twig and bud with habit as a secondary ambiguous characteristic.

The following observations demonstrate the bud characteristics of the Q. garryana taxa. Twig characteristics are not considered at this time as addational editing of the observations in needed. Changes in twig color over the growing season is not understood. More illustrative observations are required upon which to make a reasonable judgement. Also, needed is observations of the twig pubesence. Q. g. var. garryana twigs are densely pubesent where vars. breweri and semota are mostly glabrous.

Garry Oak Q. g. var. garryana
https://www.inaturalist.org/photos/180783833?size=original
https://www.inaturalist.org/photos/94398032?size=original
https://www.inaturalist.org/photos/69104464?size=original
https://www.inaturalist.org/photos/49236735?size=original
https://www.inaturalist.org/photos/36926678?size=original

Brewer's Oak Q. g. var. breweri
https://www.inaturalist.org/observations/110422345
https://www.inaturalist.org/photos/186270247?size=original
https://www.inaturalist.org/observations/89798739
https://www.inaturalist.org/photos/148330025?size=original
https://www.inaturalist.org/observations/89719711
https://www.inaturalist.org/photos/148221380?size=original
https://www.inaturalist.org/observations/64976083
https://www.inaturalist.org/photos/104540182?size=original
https://www.inaturalist.org/observations/26354578

https://www.inaturalist.org/photos/40913749?size=original

Semota Oak
https://www.inaturalist.org/observations/105440603
https://www.inaturalist.org/photos/176915543?size=original
https://www.inaturalist.org/observations/30424117
https://www.inaturalist.org/photos/47532501?size=original
https://www.inaturalist.org/observations/16142374
https://www.inaturalist.org/photos/24194491?size=original

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Publicado el agosto 11, 2022 05:01 MAÑANA por carexobnupta carexobnupta

Comentarios

The identification of the sub specific of Q. garryana has been problematic. The aviable keys are dense and ambiguous. There has been changes in the California literature suggesting a changing concept of the taxa. The observations on iNaturalist often lack detail that reveal key features. However, the Quercus garryana Range Project has gathered a sufficient number of quality observations to allow an understanding of these taxa. The current note is hoped to be a starting point as the characteristics of the twig pubesence and color, and leaf pubesence still need to be highlighted. It is my hope this effort is of value to the community and that have other views suggest an addational taxon concept. Above all, I hope this note leads to seeing the natural world with greater clarity.
M

Publicado por carexobnupta hace más de 1 año

The following iNaturalists have observations that were used to highlight the bud features in the note and are thanked for there clear observations.
@cmccarron @garyg @dcoopercem @old-bean-adams @mariahw06 @tzaddi

Publicado por carexobnupta hace más de 1 año

I will need to get some better photos of these features in any future observations. thanks for this post.

Publicado por beartracker hace más de 1 año

Yes, thank you for the post. I've been particularly poor at getting good photos lately. In part from being on crutches from a minor injury! Thanks for the post and I'll look to improve diagnostic photos.

Publicado por doug_mccutchen hace más de 1 año

Thanks for this! I still need a better camera... iPhone through a 16x hand lens loses novelty after 2 years

Publicado por tomerler hace más de 1 año

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