View source for Hesperocyparis pygmaea

{{Short description|Californian species of western cypress}}
{{Speciesbox
| image = Cupressus pygmaea, at Salt Point, Mendocino, California.jpg
| image_caption = ''Hesperocyparis pygmaea'' at Salt Point, Mendocino, California
| genus = Hesperocyparis
| species = pygmaea
| authority = ([[John Gill Lemmon|Lemmon]]) Bartel
| range_map = Cupressus pygmaea range map 4.png
| range_map_caption = Natural range of ''Cupressus pygmaea''
| synonyms_ref = <ref name="POWO">{{cite POWO |id=60451561-2 |title=''Hesperocyparis pygmaea'' (Lemmon) Bartel |access-date=2 March 2024}}</ref>
| synonyms = {{Collapsible list |
 {{Species list
 | Callitropsis pygmaea | (Lemmon) D.P.Little (2006)
 | Cupressus goveniana subsp. pygmaea | (Lemmon) Bartel (1991)
 | Cupressus goveniana var. pygmaea | Lemmon (1895)
 | Cupressus pygmaea | (Lemmon) Sarg. (1901)
 | Cupressus silbae | B.Huang bis (2008)
 | Hesperocyparis goveniana var. pygmaea | (Lemmon) de Laub. (2012)
 | Neocupressus goveniana var. pygmaea | (Lemmon) de Laub. (2009)
}}
}}
}}

'''''Hesperocyparis pygmaea''''', the '''Mendocino cypress''' or '''pygmy cypress''', is a [[taxon]] of disputed status in the [[western cypress]] genus. It is [[endemic (ecology)|endemic]] to certain [[coast]]al terraces and coastal mountain ranges of [[Mendocino County, California|Mendocino]] and [[Sonoma County, California|Sonoma Counties]] in northwestern [[California]]. It is a variable tree, and closely related to ''[[Hesperocyparis abramsiana]]'' and ''[[Hesperocyparis goveniana]]'', enough to sometimes be considered conspecific with them.

==Description==
The [[foliage]] is a dull dark to light green color, with scale-like [[leaf|leaves]] 1–1.5&nbsp;mm long, with the leaf tips not spreading; seedlings bear needle-like leaves 8–10&nbsp;mm long. The [[conifer cone|cones]] are small, 11–24&nbsp;mm long, and almost spherical, with six or eight scales arranged in opposite decussate pairs, with the bract visible as no more than a small lump or short spine on the scale. The [[seed]]s are 3–5&nbsp;mm long, with a pair of small wings along the sides.<ref name="Farjon" /> The cones remain closed on the trees for many years, until the trees are killed by a forest fire; after the tree is dead, the cones open to release the seeds which can then germinate successfully on the bare fire-cleared ground.<ref name="Lanner" />

The Mendocino cypress differs little from ''H.&nbsp;goveniana'' in morphology, with the most conspicuous difference in [[herbarium]] material being the usually glossy black seeds, unlike the dull brown seeds of ''H.&nbsp;goveniana'', but even this character is not constant, with dull brown seeds found in the southernmost populations of ''H.&nbsp;pygmaea'' near [[Point Arena, California|Point Arena]].<ref name="wolf" /> Preliminary genetic studies have shown some differences, with notably some [[plastid]] sequences (''matK'', ''rbcL'', and ''trnL'') suggesting a possible closer relationship to ''[[Hesperocyparis macrocarpa|H.&nbsp;macrocarpa]]'', though other sequences confirm its close relationship to ''H.&nbsp;goveniana''.<ref name="Little2006">{{cite journal |author=Damon P. Little |year=2006 |title=Evolution and circumscription of the true cypresses (Cupressaceae: ''Cupressus'') |journal=[[Systematic Botany]] |volume=31 |issue=3 |pages=461–480 |jstor=25064176 |doi=10.1600/036364406778388638}}</ref> In cultivation together with ''H.&nbsp;goveniana'', it retains a very different crown shape, with a tall slender crown, contrasting with the broad, shrubby crown of ''H.&nbsp;goveniana''; it also has darker green foliage (paler, yellow-green in ''H.&nbsp;goveniana'').<ref name="wolf" />

The largest recorded specimen is located in Mendocino County, with recorded dimensions of 43&nbsp;m height, 2.13&nbsp;m diameter, and 12&nbsp;m crown spread, in 2000.<ref name="Gymnosperm DB">{{cite web |editor1-last=Earle |editor1-first=Christopher J. |title=''Hesperocyparis pygmaea'' (Mendocino cypress) description |url=https://www.conifers.org/cu/Hesperocyparis_pygmaea.php |website=The Gymnosperm Database |access-date=4 March 2024 |language=en |date=2023}}</ref>

==Taxonomy==
''Hesperocyparis pygmaea'' was first described as a [[subspecies]] by [[J.G. Lemmon]] with the name ''Cupressus goveniana'' var. ''pygmaea'' in 1895. It was described as a species by [[Charles Sprague Sargent]] in 1901.<ref name="POWO" /> Sargent thought that the distinctness of the seeds from those of ''C.&nbsp;goveniana'' definitively showed it to be a species though its growth habits and form did not make it easy to identify.<ref>{{cite journal |last1=Sargent |first1=Charles S. |author1-link=Charles Sprague Sargent |title=New or Little Known North American Trees. III |journal=Botanical Gazette |date=1901 |volume=31 |issue=4 |pages=239–240 |url=https://www.biodiversitylibrary.org/page/28545470 |access-date=2 March 2024}}</ref>

Its taxonomic status is a long standing matter of dispute between botanists. In the 20th century some treated ''Cupressus pygmaea'' as a distinct species, following Sargent, including Wolf (1948),<ref name="wolf">{{cite journal | last1 = Wolf | first1 = C. B. | last2 = Wagener | first2 = W. E. | year = 1948 | title = The New World cypresses | journal = Aliso | volume = 1 | pages = 195–205 |  issue=1| doi = 10.5642/aliso.19480101.02 | doi-access = free }}</ref> Griffin & Critchfield (1976),<ref name="Distribution">{{cite report |last1=Griffin |first1=James R. |last2=Critchfield |first2=William B. |date=1976 |title=Research Paper PSW-82: The Distribution of Forest Trees in California |url=https://www.fs.usda.gov/research/treesearch/28747 |publisher=USDA Forest Service |access-date=5 March 2024}}</ref> and Lanner (1999).<ref name="Lanner">{{cite book |last1=Lanner |first1=Ronald M. |title=Conifers of California |date=1999 |publisher=Cachuma Press |location=Los Olives, California |isbn=0-9628505-3-5 |pages=176–177 |edition=2. print |url=https://archive.org/details/conifersofcalifo0000lann/page/176 |language=en}}</ref> Others treated it within ''[[Cupressus goveniana]]'' as either a [[variety (biology)|variety]] (''C. goveniana'' var. ''pigmaea'' Lemmon)<ref>Lemmon, J. G. (1895). ''West-American Cone-Bearers''. 3rd ed.</ref> or a [[subspecies]] (''C. goveniana'' subsp. ''pygmaea'' (Lemmon) A.Camus), including Camus (1914),<ref>{{cite journal | last1 = Camus | first1 = A | year = 1914 | title = Les Cyprès | journal = Encyclopédie Économique de Sylviculture | volume = 2 | page = 50 }}</ref> and the ''Jepson Manual'' (1993),<ref name="jepson">{{Jepson Manual |id=157,160,167,169 |taxon=Cupressus pigmaea subsp. pygmaea |first=Jim A. |last=Bartel}}</ref> and one publication, the ''[[Flora of North America]]'', did not distinguish it at all within ''C.&nbsp;goveniana''.<ref>{{eFloras|1|200005418|Cupressus goveniana |first=James E. |last=Eckenwalder |volume=2}}</ref>

The spelling of the scientific name has also been confused. Lemmon's [[protologue]] at varietal rank used the spelling ''pigm a'', a typographic error hand corrected to ''pigmaea'', in the main description ({{BHL page|23343470|77}}) but ''pygmaea'' in the contents ({{BHL page|23343396|xiv}}). In raising the taxon to species rank, Sargent changed the spelling to ''pygmaea'' ({{BHL page|28545470|239}}), a legitimate change as a botanical name has no priority outside of the rank at which it is published ([[International Code of Nomenclature for algae, fungi, and plants|''ICN'']] Art. 11.2); this has been followed by most subsequent authors (including Camus in the first allocation to subspecific rank [https://archive.org/details/lescyprsgenrec00camu/page/50/mode/1up]), though a few subsequent authors have incorrectly used the spelling ''pigmaea'' at ranks other than varietal (e.g. Farjon 2005,<ref name="Farjon" /> Little 2006<ref name="Little2006" />).

Disputes continued into the 2000s with Farjon agreeing that it should be part of ''C.&nbsp;goveniana'' in 2005.<ref name="Farjon">{{cite book |last1=Farjon |first1=Aljos |title=A monograph of cupressaceae and sciadopitys |date=2005 |publisher=Royal botanic gardens |location=Kew, England |isbn=1-84246-068-4 |pages=205, 272 |language=en}}</ref> Additionally moving the new world cypress species to different genera was proposed three different times. In 2006 Damon P. Little proposed moving them to ''[[Callitropsis nootkatensis|Callitropsis]]'', but did not find wide acceptance.<ref name="Little2006" /><ref name="POWO" /> In 2009 two different classifications were proposed, ''[[Hesperocyparis]]'' and ''Neocupressus''.<ref name="POWO" />

{{As of|2024}} ''Hesperocyparis pygmaea'' is listed as the correct name in [[Plants of the World Online]],<ref name="POWO" /> [[World Flora Online]],<ref>{{Cite WFO |title=''Hesperocyparis pigmaea'' (Lemmon) Bartel |id=0000912977 |access-date=5 March 2024}}</ref> and the Gymnosperm Database.<ref name="Gymnosperm DB" />

==Distribution and habitat==
The Mendocino cypress is highly variable in growth form, depending on soil conditions. In the [[pygmy forest]] plant community on poor, [[acid]]ic, [[nutrient]]-starved [[podsol]] soils with drainage impeded by an [[hardpan|iron hardpan]], it is a stunted tree from 0.2–5&nbsp;meters in height at maturity. When occurring in its pygmy form, it is sometimes called '''pygmy cypress'''.  When growing on deep, well-drained soils it can be a large tree up to 30–50&nbsp;meters in height and 1–2.4&nbsp;m in trunk diameter. The [[Bark (botany)|bark]] is dark gray-brown, with stringy texture, and fissured on old trees.<ref name="Farjon" />

Mendocino cypress occurs in very limited ranges within only [[Mendocino County, California|Mendocino County]], on some of the historical lands of the [[Yuki tribe|Yuki]] Native American people. In Mendocino County the occurrence is in a discontinuous [[coast]]al terrace strip, primarily as a pygmy forest associated with [[bishop pine]] (''Pinus muricata'') and [[Lodgepole Pine|Mendocino shore pine]] (''P. contorta var. bolanderi''). Occurrences are typically below 500&nbsp;m in elevation.<ref name=jepson/> The Mendocino County official [[soil]]s survey states that "While not formally recognized as a major forest cover type, the coastal portion of the survey area also includes bishop pine and Mendocino cypress (pygmy) forest types".<ref>{{cite web|url= http://www.ca.nrcs.usda.gov/mlra02/wmendo/woodland.html|title= Woodland Management and Productivity|accessdate= 2006-11-23|year= 1993|work= Soil Survey of Mendocino County, California, Western Part|publisher= National Cooperative Soil Survey|url-status= dead|archive-url= https://web.archive.org/web/20060923083427/http://www.ca.nrcs.usda.gov/mlra02/wmendo/woodland.html|archive-date= 2006-09-23}}</ref>

==Productivity==
Along the Mendocino coastal terraces, whose geological age is approximately one million years, studies have been conducted of the biomass density and [[primary productivity]] of the ''Hesperocyparis pygmaea''-dominated pygmy forest.<ref>Westman, W. E. & Whittaker, R. H. (1975). The Pygmy Forest Region of Northern California: Studies on Biomass and Primary Productivity. ''Journal of Ecology'' 63 (2): 493-520. {{ISSN|0022-0477}}.</ref> The terraces in this area extend a full five to ten kilometers inland from the [[Pacific Ocean]].

In the Mendocino cypress pygmy forests, [[biomass]] was measured to range between 1.6 and 4.4&nbsp;kilograms per square meter aboveground; moreover, net primary productivity was found to measure 180 to 360&nbsp;grams per square meter per annum above the ground surface. Mean below-ground values are 3.5&nbsp;kilograms biomass per square meter, productivity being 402&nbsp;grams per meter per annum. The [[leaf-area ratio]] of the pygmy forest was estimated as 2.1&nbsp;grams per square meter implying a high production efficiency per unit leaf area for an [[evergreen]] community (150&nbsp;grams per meter aboveground <!--what does this 150 grams number represents? an average number for evergreen forests?-->). According to Westman, productivity of the ''H.&nbsp;pygmaea'' forest lies within the range expected for open, dry [[woodland]]s. A similar community for which data is available is a pygmy conifer-oak scrubland in southern [[Arizona]].

==References==
{{Reflist}}

==External links==
{{Commons category-inline|Cupressus pygmaea}}
{{Cupressaceae}}
{{Taxonbar|from=Q5194573}}

[[Category:Hesperocyparis|pygmaea]]
[[Category:Endemic flora of California]]
[[Category:Trees of Northern America]]
[[Category:Natural history of the California Coast Ranges]]
[[Category:Natural history of Mendocino County, California]]
[[Category:Natural history of Sonoma County, California]]
[[Category:Trees of mild maritime climate]]
[[Category:Plants described in 1895]]
[[Category:Flora without expected TNC conservation status]]