How many species of Santa Cruz Cypress are there?

Botanists have not agreed upon use of categories to classify hierarchical variation pattern.  As I see it, trinomials are a type of botanical hedge-fund.  We name a taxon (‘we buy it’), then we purchase a derivative against its being ‘lumped’ as a hedge by treating it as an infrataxon.  Moreover, there are no regulatory mechanisms governing the choice of category in the hierarchy.  Sound familiarly like a financial meltdown?  Some authors publish boatloads of new combinations because it is their habit to use solely a single category of infrataxon.  Literature pollution?

The utility of recognizing infrataxa is not well codified in modern usage.  Hamilton & Reichard (1) document the fact that most taxonomists employ only a single hierarchical category below the rank of species, and that two schools of thought are evident: those whom use the category “subspecies” or those that use “variety”. but few botanists use both.  As Fosberg (2) notes there is no specific prohibition against the practice, perhaps due to an instinctive aversion to quadranomials.  The vast majority of authors fail to provide a rationale for their choice of infraspecific category, or for their viewpoint upon the question of parsing variation into a hierarchical topology. 

Recently, the question arises in the case of the Santa Cruz Cypress. and endangered tree: Silba (3) named 5 subspecies.  Adams & Bartel (4), eventually after some hemming, treat 2.  One might choose to treat the Silba infrataxa as varieties within subspecies; others would want to make them formae (although the nature of forma seem to lack consensus in the literature: mostly forma are taken to be sporadic, rare phenotypes that may not have a genetic basis, that is, the condition may be developmental; or, their genetic basis is viewed as a mutation, albinism in flower color is an example.    There is arboricultural utility in considering the Silba infrataxa as cultivars would be o.k. as “C.V.” would eliminate confusion, but unfortunately horticultural nomenclature in practice is in my experience inaccurate.

Fernald (5) would probably have treated H. abramsiana ssp. abramsiana and within it H. abramsiana var. locatellii, H. abramsiana var. neolomondensis and H. abramsiana var. opleri, and H. abramsiana ssp. butanoensis. 

I could question the decision as to how to parse variation within H. abramsiana by noting that for some individuals of ‘neolomondensis’ their chemical profile was as distinct as is ssp. butanoensis, and ‘opleri’ was about as removed in the ISSR ordination but it also differed in mean cone width, length and number of scales.  Faced with practical necessity, the Adams and Bartel treatment is useful, but one could also craft an alternative classification just as readily. 

The pattern of relationships Adams & Bartel find are suggestive of genetic drift following upon segmentation of a variable, ancestral panmictic population: in some respects, one answer is there are either no subspecies of Santa Cruz cypress, but there are five groves.

I will also make reference to the choice between treating these plants in Cupressus as has been traditionally done: Little (6) made out our cypresses to be polyphylletic  within Cupressus.  By aversion to lumping them into Juniperus (6) out Hesperocyparis was cleaved.  There is also evidence that all cupressus are a single clade (7)  I like the latter approach because by their very nature genera are small (8) and in this instance the Hesperocyparis-Cupressus division is a deep one. 

1. Hamilton, C. and S. Reichard.  1992.  Taxon 41:485-498

2. Fosberg, F. 1942.  Rhodora 44:153-157

3.  Silba, J.  2003 Intern. Conifer Pres. Society 10:1-49

4.  Adams, R and J Bartel. 2009 Phytologia 91(2):287-299

5.  Fernald. M. 1941.  Rhodora 43:156-167.

6. Little, D. 2006 Syst. Bot. 31:461-480.

7. Mao, K. et al. 2010.  New Phytologist 188: 254–272

8.  Cronk, Q.C.B. 1989.  Taxon 38(3):357-370.

Cladoptosis in Redwood (Sequoia sempervirens)

Cladoptosis is the shedding of plant canopy units.  

In many conifer 'leaves' – needles – are retained for a period of years, then are usually shed as units consisting of the needles, sheathing bracts, and associated short shoot.   In Redwood (Sequoia sempervirens), leaf surface area in the canopy is renewed by shedding of sheathing bracts, long shoots and associated needles.  The location and expression of an abscission zone is such that often two or perhaps three year old leaves are often shed, but sometimes abscission occurs after one year.  One potential function regulation of cladoptosis in Redwood could involve the value of the leaf area vs. the propensity for the leaves to become colonized by lichens.  Lichen covered leaves presumably are less effective photosynthetically, so their renewal and replacement would be a function of lichen interactions.    The dynamics of this process suggests that abscission might have a regulatory feedback controlled by leaf ‘worth’.

The photo shows two leaf segments of Redwood that were shed as a single unit, the lower segment 2 yr old, with lichen colonization over about one-third of the two year old portion of the leaf unit, and a few new lichen'ets' beginning on the tip of the one year old portion of the leaf unit

Rare Plant Density by County in California

A total of 2260 native plants are listed as rare in California.  On a density basis, the mean density is 0.33 plants/km² (based on October 2011 CNPS Inventory records) for the 406,388 km².  The inequality on a density basis is evident in the map:  the counties with the highest density statewide are in the San Francisco Bay region, generally.    Most of the northern counties of the state have a density that is less than the mean density, while the larger area counties of southern California have a density that is <1/4 of the mean (that is, below 0.16).  Another hot-spot are the southern three coastal counties. 

Of course absolute numbers for many low density counties are high: Inyo County supports 275 rare plants and San Bernardino County 374, yet on a density basis these jurisdictions are very low.  Kings County supports only 22 plants and is also low density.

Ramets in Poa sierrae

Poa Section Madropoa is mostly restricted to high mountains of western North America: the exception is one species, Poa cuspidata of the ne U.S.  Of the 25 taxa total in the Section (FNA Vol. 24), most species are fairly widely distributed (except P. chambersii).  P. porsildii, an alpine calciphile, is the sole taxon, outside the limits of the western Cordillera (Rocky Mountains-Cascade-Sierra axis). 

Within the California Floristic Province, there are 8 endemic taxa of Poa Section Madropoa, a distinctive concentration. 

CAFP endemics

“Poa nervosa complex”

Poa rhizomata and Poa sierrae

Subsection Madropoa

Poa douglasii, Poa diaboli, Poa piperi and Poa atropurpurea

Subsection Epiles

Poa stebbinsii and Poa pringlei

Poa sierrae is odd in the clade: it is characterized by being rhizomatous, dioecious and by the distinctive scaly ‘bulbils’ produced on the rhizomes.  These ramets doubtless propagate by fragmentation, so it is puzzling why P. sierrae is quite narrowly distributed.  These ramets are nicely afforded 2x the page space in FNA Vol. 24 (p. 550) –fame!

This season, I visited “Lewisia rock” in the Feather River canyon, and collected P. sierrae at the type station.  On August 1^st, the plants were still green but had flowered perhaps mid-June.  Collecting the material, I retained some rhizomes to cultivate.  Now, 6 weeks later after being potted and water, new growth is underway.

The top photo shows ramets field collected along a rhizome, in the fully dormant state.

The middle photo shows the larger ramet of the top photo after being potted where the base was set just at the soil surface, and after 6 weeks has not yet left dormancy: about 2 cm long

The lower photo shows two ramets: the left one is about 2 cm long and nicely expanding.  The smaller right-hand one is about 0.5 cm long and has just triggered.

Genets in Brodiaea matsonii

Today I de-potted a pot of Brodiaea matsonii. The 1-gal pot was the only pot of 4 pots which flowered in 2011; upon inspection, the mode of vegetative propagation was readily apparent. Daughter bulbs begin on the stem (putative in the sense that I refer to the portion of the corm just apical of the root pad). Being lax, I did not consult literature (Mecalf & Chalk would probably prove me anatomically wrong). The photo shows three large corms, each with a genet attached (Left to Right: 3 o’clock, noon, and 7 o’clock).

In monocots such as Brodiaea, vegetative propagation is perhaps numerically more important demograpically than sexual reproduction.

16000 western North American Herbarium Specimen Records - DWTaylor

I have posted a tabulation of 16,000 of my 21,000 vascular plant herbarium specimen records on Google Fusion. Search on 16000 western North American Herbarium Specimen and DWTaylor to pull up the dataset. There are a few records that are mapping screwy. About 1,000 records are of sufficiently poor quality for label information that they are as yet not georeferenced. For about half of these records, a known accession number is given. A sizable number of accessions at DAV are not yet posted on the Consortium of California Herbaria database.

An approximate tabulation by location is:

Alaska 19

Alberta 18

Arizona 58

Baja California Norte 142

Baja California Sur 93

British Columbia 64

California 12,845

Colorado 445

Hawaii 3

Idaho 318

Montana 55

Nevada 443

New Mexico 186

Oregon 830

Texas 49

Utah 52

Washington 179

Current 2011 Herbarium Specimen Density for California

A key took to understanding the California flora is the availability of observation and specimen records. The CCH web portal shows statistics for specimen density for each of the 58 California counties. Here, I summarize these data by county. With 1.2 million specimens databased, the mean collection density state wide is 3.2 specimens/square kilometer. The striking pattern obtained by mapping specimen density within quartiles on a county basis is the inequality pattern: slightly over half of counties fall below the mean. but a sizable number of counties (San Benito, Fresno, Shasta, Glenn, Stanislaus, Imperial, Madera, Lassen, Merced, San Joaquin and Kings) fall in the lower quartile (that is, below 1.6 specimens/km2). The undercollected nature of Kings County can be attributed to little remaining natural habitat, as might be argued for Madera and Fresno Counties. However, if we discount the ag portions of these counties (at roughly half their area), their specimen density still falls below the median. Understandably, the lower herbarium specimen density for Shasta and Lassen counties is owing to remoteness.

as Jepson's bookplate admonished "something is still lost beyond the ranges, over yonder go ye' there"

But go ye to the lower quartile counties.