Bryolog 20 (27 May 2020)


As a general policy, check the website for event updates before you walk out the door!

  • Hey students, we now are accepting applications for travel scholarship as well as for mini-grants. They are due 1 July and 1 January: RFP…
  • Due to Covid-19 concerns, David Wagner’s bryophyte identification workshop scheduled for 28 September to 2 October 2020 is cancelled and will be rescheduled for the fall of 2021 or 2022.
  • Most of you know we had to cancel our annual foray and chapter meeting SO BE FREE this year due to that pesky virus that’s going around, but the venue we selected was so great we felt we had to give it another go. For 2021, SO BE FREE will be held 26-29 March at Saratoga Springs Retreat Center near Clear Lake north of the little town Upper Lake, California. We will be in the heart of the North Coast Ranges, with a diverse flora ranging from redwoods and mixed evergreens in the lower elevations near the coast, to boreal forests and rocky crests in the higher elevations, to savannas, chaparral, and oak woodlands of the lower elevations in the interior.

SAVE THE DATES! You can register at Discounts and a free T-shirt are available for early registrants. For students, we also have a payment-plan option. See you there!

Quarterly Report

Timeless Bits

Human-wildlife conflicts while studying desert mosses

—Jenna T. B. Ekwealor
UC Berkeley
CNPS Bryophyte Chapter Mini-grant awardee

In spring 2018 I launched a field experiment to test the effects of UV radiation on mosses. You see, I study mosses that live in an environment with intense solar radiation: the Mojave Desert. Those of you who have been to Chapter events might already be familiar with desert mosses (GrimmiaDidymodon, and the “star” of the show, star mosses Syntrichia), but it’s still pretty remarkable, isn’t it? Mosses, plants that are normally found in cool, low-light, wet conditions, are actually quite abundant in hot, dry deserts. Though, it’s usually the same, relatively few, specialized taxa. My research focuses on adaptive mechanisms for life as a moss in the desert. In particular, I’m interested in how Syntrichia spp. tolerate the excessive solar radiation, especially while dry and unable to perform photosynthesis or repair any damages incurred.

Last year, the CNPS Bryophyte Chapter awarded me a mini-grant to continue my project, the last step of which was to set out temperature loggers for several months to collect microclimate data. Mosses, being so small, can experience very different climatic conditions depending on where they are located in their environment. Under an overhanging boulder, for example, can be heavily shaded and quite cool, even in a desert. I am happy to say data collection for my field experiment is complete and my results will be submitted for publication soon. However, that is not what I’m here to talk about. I wanted to tell the story of how pack rats tried to sabotage my experiment. Twice.

person with computer in the desert
Me unloading data from microclimate loggers in the Sweeney Granite Mountains Desert Research Center, Mojave Desert

First, an introduction to pack rats. The pack rats in my site at the Sweeney Granite Mountains Desert Research Center in the Mojave Desert are called desert woodrats, or more formally, Neotoma lepida. They are small for rats and have proportionally large ears. They’re adorable! They are nocturnal and live in complex houses known as middens with several chambers inside. Woodrats will pass middens on for generations and generations, and guard them fiercely. Desert woodrats will pack the entries to their middens with thick layers of cactus burrs and spines to deter potential invaders. Pack rats are also known as “trade rats” because of their fondness for collecting treasures. They are known to trade items they might be carrying if they come across something more interesting. They find shiny things especially interesting.

small mammal on similarly colored gravel
A desert woodrat (Neotoma lepida) being released from a live trap

So, last fall I was out in my field site in the Granite Mountains to collect six temperature loggers but there was a problem. The first five were in place and all was well with them but one was missing. I thought maybe it had been blown away in a big windstorm. Windstorms are not uncommon out there. Though, these sensors were somewhat large and heavy, so even if it was windy, I couldn’t imagine it would go very far. Yet, it was nowhere near where I installed it. Then I thought maybe there was a big summer monsoon that washed it farther away. However, when I followed the slope down to the little wash I couldn’t find it anywhere there, either. It certainly would have gotten stuck on a nearby shrub, yet it was simply nowhere to be found. I gave up for the day and began my hike back to the lodge. As I was walking back, I kept running over the scene in my mind’s eye. Just a few feet from where the sensor was, I could see an odd collection of spiny buckhorn cholla burrs. There were definitely way more on this little ledge between boulders than would be there naturally… Was that a desert woodrat midden? Could they have taken my sensor? I ran my new hypothesis by the reserve directors, and they returned with about a hundred stories of woodrat thievery out in the Mojave. It was definitely a woodrat and there’s no way I’m getting it out of their chambers. Well, imagine my surprise when I went back out and saw my sensor right on the front porch of the woodrat midden next to my site! It looked like the sensor got stuck on the massive hoard of cholla burrs as it was trying to take it to its lair. I was pleased to get the sensor back but actually much more pleased about having solved the mystery.

device with cable tie
A second temperature logger stolen by a woodrat


smiling human
Me, very excited to see my temperature logger in the entry of a desert woodrat midden


device amid prickly cholla
A microclimate logger stuck in the entry to a desert woodrat midden

A few months later yet another temperature logger had apparently vanished into thin air in a different part of the field site. Again, I first searched the area to see if it had been blown around or washed away—nothing. I immediately switched gears and began searching for all the nearby woodrat middens. Lo and behold, I found my data logger, again stuck, this time on a shrub, just outside a woodrat midden entry. Thankfully, these rats seem to give up readily when their treasure fights back! It turns out these temperature loggers flash every few seconds while they’re recording data. And while desert woodrats like shiny objects, these nocturnal treasure collectors apparently really like flashing items. Lesson learned: don’t leave small, flashing objects in woodrat territory (unless it’s a gift for a woodrat. Then by all means, carry on!).

A Summer Collecting Bryophytes in the Sierra Nevada

—Charlie Gibbons
Cal Poly San Luis Obispo
CNPS Bryophyte Chapter mini-grant awardee


Bryophytes represent a unique and diverse lineage of land plants and are important to ecosystem function around the globe, including in alpine habitats. Bryophytes in alpine environments create unique living substrate that likely affects the realized niche of many other species (Bueno et al. 2016). For example, bryophytes are important in the hydrologic cycle, ecology of alpine meadows, slope stabilization, soil processes, and regulating the acidity of sites. These alpine environments are known to be biodiverse environments which are ever increasingly threatened by the impacts of climate change (Rundel 2011). As average global temperatures continue to rise (IPCC2007), species that call alpine environments home are increasingly at risk of extirpation due to climate change (Parmesan 2006).

The Sierra Nevada mountain range harbors much of California’s alpine habitat, occurring above tree line and at elevations greater than 3500 m (Rundel 2011). To build an understanding of alpine plant response to climate change in California, Cal Poly Master’s student Dena Paolilli has put together a project and crew to resurvey National Resource Inventory (NRI) vegetation plots throughout Sequoia and Kings Canyon National Park. Like most plant resurveys, the focus was on vascular plants. But, what about the bryophytes? During the 2019 field season, while helping Dena with the vascular plants, I collected and vouchered specimens of bryophytes found in and around these plots. These collections will serve as the basis for our understanding of the bryophytic flora associated with these alpine plots, and could be used to examine future changes in alpine bryophytes.

Background on Sierran Bryophytes—In California, there are 508 species of mosses, 116 species of liverworts, and 6 species of hornworts. A number are endemic to California (SNFPA). Narrowing in on the Sierra Nevada, there are two endemic species of moss, Grimmia hamulosa and Orthotrichum spjutii, but no liverworts or hornworts that only grow in the high Sierra (Shevock 1996). Using the mapping tool from the Consortium of North American Bryophyte Herbaria, I found that ~372 bryophyte taxa were previously collected within Sequoia and Kings Canyon National Parks. These taxa occur from the foothills to the very highest alpine environments of the Sierra Nevada. It is likely that only a subset of these species occur in the alpine zone.


The manner in which these collections were performed is intrinsically linked to the study design of the NRI plot vegetation resurvey. The plots were originally established in the 1980s and 1990s along a grid system with each plot 1 kilometer apart. In 2019, plots were relocated and resurveyed by a crew of botanists. During these surveys, I collected and vouchered bryophytes from just outside each plot. No collections were made from inside the plot so that diversity and abundance would not be impacted for future surveys. I attempted to collect material of all morphotypes observed within the plot as well as any novel morphotypes. Collected specimens were bagged together by plot and subsequently sorted into collection packets for each individual species. Location information and habitat descriptions were also recorded with each collection. In winter 2019, specimen identifications were made by Dr. Paul Wilson of California State University Northridge. At least one specimen of each taxa was then processed to fit in a collection packet. Specimens were chosen based on quality and quantity of material collected. Collection data was then finalized on the packet and all packets were deposited at the Hoover Herbarium, Cal Poly San Luis Obispo.

Photos taken of bryophytes in the field were uploaded to CalFlora as species occurrences under the observer name Charles Gibbons.


I collected 67 total specimens from 20 different alpine locations and from 12 total NRI plots in the Sequoia and Kings Canyon region. These specimens consist of 24 different moss taxa from 11 families.

Figure 1: This figure shows the multiple collection localities, in red, from the summer in relation to the Sequoia and Kings Canyon Park in blue

This represents approximately 5.6% of the diversity of bryophytes in the entire Sierra Nevada ecoregion, determined by comparing taxa lists of collections from this summer to taxa collection lists from the Consortium of North American Bryophyte Herbaria’s Map Search tool. Note that this percentage is a number that includes all species in the entire Sierra Nevada ecoregion, not solely the alpine zone. The total number of taxa inhabiting the alpine is likely to be lower. Of the 67 total specimens collected, approximately 40 were deposited in the Hoover Herbarium.

Figure 2: An observation of Tortula hoppeana that has been published to CalFlora

The most commonly collected species from the season were Tortula hoppeanaAulocomnium palustre, and Polytrichum piliferum. These three moss species are considered to be generalists and have a wide distribution across the Northern Hemisphere. None of the species collected were rare taxa as listed by the Sierra Nevada Ecosystem Project.


This study had three main outcomes: (1) a collection of alpine bryophytes for the Hoover Herbarium, (2) the beginnings of a baseline for bryophyte species associated with alpine NRI plots, and (3) an enlightening introduction to field bryology for myself. As the original NRI surveys had not recorded species of bryophytes throughout the plots, there was a need for work with the taxa associated with these resurveys. Recording species of bryophytes does remain difficult due to the nature of these permanent plot surveys as collections cannot be made from inside the plot. Thus, species identifications must be made off of sight identification in the field, from specimen photographs, and from specimen collections from around the plot. This collection project made the first attempts to record bryophyte species from the 72 plots surveyed in 2019. Being a novice bryologist without familiarity of Sierran bryophytes, it proved difficult to near impossible to locate and voucher all morphotypes outside the plots that were observed within the plot itself. Further, I found I had collected many of the same species over and over, and likely missed rare species, as no one on our crew was skilled enough with bryophytes to tell species apart in the field. This is evident in the collections in which there are many prolific species that were repeatedly collected from the same locality under the impression they were different species. Improvements will be made with time as I gain experience with bryophyte identification.

One surprise while doing background research for this project was the relatively understudied nature of bryophytes in alpine environments of California. Most research focusing on bryophytes and their ecological role as species come from European Alps and the Eastern United States at much lower elevations.

How many bryophytes are there in the Sierran alpine, and where do they occur? Floristic surveys that focus on bryophytes are necessary to understand what is out there, where it can be found, and what role bryophytes play in shaping the ecosystem as a whole. Much insight about bryophytes remains hidden away in the backcountry of the Sierra Nevada, waiting to be unearthed.

The remoteness of much of the Sierra Nevada makes the study of bryophytes there especially challenging. Oftentimes, botanists who are hardy (and crazy) enough to make it to these locations are untrained in bryophyte identification and collection skills. This project was my small attempt to begin to rectify this issue. In the future, I will continue to voucher alpine bryophytes and I hope to continue to develop and disseminate new insight into this understudied system.


Table 1 : Taxa collected in the 2019 field season
Species (Family)
Amblystegium serpens (Amblystegiaceae)
Aulacomnium palustre (Aulacomniaceae)
Bartramia sp. (Bartramiaceae)
Bartramia ithyphylla (Bartramiaceae)
Blindia acuta (Seligeraceae)
Brachythecium sp. (Brachytheciaceae)
Ceratodon purpureus (Ditrichaceae)
Gemmabrum kunzei (Bryaceae)
Grimmia sp. (Grimmiaceae)
Liverwort sp.
Philonotis fontana (Bartramiaceae)
Pohlia sp. (Bryaceae)
Pohlia bolanderi (Bryaceae)
Pohlia cruda (Bryaceae)
Pohlia drummondii (Bryaceae)
Polytrichum juniperinum (Polytrichaceae)
Polytrichum piliferum (Polytrichaceae)
Imbribryum alpinum (Bryaceae)
Ptychostomum weigellii (Bryaceae)
Sanionia uncinata (Amblystegiaceae)
Sphagnum sect. subsecundum (Sphagnaceae)
Straminergon stramineum (Calliergonaceae)
Syntrichia norvegica (Pottiaceae)
Tortula hoppeana (Pottiaceae)

Literature Cited

Shevock, James R. 1996. “Sierra Nevada Ecosystem Project: Status of Rare and Endemic Plants.” U.S. Forest Service.

Bueno CG, Williamson SN, Barrio IC, Helgadóttir Á, HiK DS. 2016. “Moss Mediates the Influence of Shrub Species on Soil Properties and Processes in Alpine Tundra.”

Rundel, Philip W. 2011. “The Diversity and Biogeography of the Alpine Flora of the Sierra Nevada of California” Madroño 58: 153–184.

Powell, Bradley. 2001. “Sierra Nevada Forest Plan Amendment: Final Environmental Impact Statement.” United States Department of Agriculture.

Message from the President

—Brent Mishler

I was honored to take over this April as president of the CNPS Bryophyte Chapter! I’d like to start off by thanking outgoing president Jim Shevock for all his dedication to the Chapter, and his hard work. I’d also like to thank Paul Wilson, who was our founding president and served before Jim, for his continued efforts to serve the Chapter. Our Chapter Board works hard to keep us going: treasurer Kiamara Ludwig, fieldtrip director Bill Thiessen, and secretary Larke Reeber all continue their dedicated service on the Chapter Board for the next year. Ben Carter began serving as president-elect in April and is a great addition. Special thanks also to Amada Heinrich for her long-time work as Bryolog editor! Please consider serving as an officer in the future; feel free to get in touch with me to volunteer to stand for election.

SO BE FREE is our flagship event. Let’s have a great turnout for next year (March 26-29, 2021 at Saratoga Springs). I know we are all ready to get back out in the field, observe bryophytes and interact with our fellow bryologists! All the information, plus registration form are here: Register A.S.A.P. to get an “early bird” discount and a free T-shirt! As always we offer a student discount; this year we have added a payment plan for students.

Please join or renew your membership to CNPS and the Bryophyte Chapter; this allows us to continue our chapter activities, not to mention that it will give you another $25 off registration for SO BE FREE! You can do it directly from our Chapter homepage Just be sure to list Bryophyte as your chapter affiliation (and you can also affiliate with your local CNPS chapter without any additional cost).

The Bryophyte Chapter aims to study California’s mosses, liverworts, and hornworts, increase public understanding and appreciation of them, and protect them and the habitats in which they grow. Each year we try to add new contributions in all these areas, but we need your help. There are many things you can do personally to help: collect poorly known regions, observe phenology and ecological associations of bryophytes, teach people about them by leading walks and workshops, and be sure bryophytes are considered in your local conservation activities. Feel free to contact any of the folks on this list: including the liaisons with your local CNPS chapters. And most importantly, come to SO BE FREE!

Report on Shasta Chapter Bryophyte Workshop, February 2020

An impressive number of enthusiastic attendees turned out for the two-day bryophyte workshop offered by Scot Loring for the Shasta CNPS Chapter held at Shasta College in February. The workshop was split into three stand-alone events: a field trip to Waters Gulch Trail at Shasta Lake, an evening slide show, and a hands-on lab with collections and microscopes. Each component attracted different attendees, although there was much overlap. Participants included federal and state agency personnel, students from Shasta College and elsewhere, and people from the general public. Everyone showed a high level of interest and the people from the Shasta Chapter and Shasta College were very accommodating.


person and screen
Scot showing his slides


people using microscopes
Microscopes at work

So What Has Happened to Orthotrichum?

—Jim Shevock, California Academy of Sciences

Among California mosses, the genus Orthotrichum is widespread and readily recognized because it generally produces abundant capsules with rather diagnostic golden erect hairs on the calyptrae.

moss macrophoto
Golden hairy calyptra, Lewinskya bolanderi (Orthotrichum bolanderi)

The genus Orthotrichum was established in 1801 by Hedwig in Species Frondosum. At least 120+ species of Orthotrichum are currently recognized. The genus is well-distributed globally and is especially species-rich within areas harboring a mediterranean-type climate. However, the moss family Orthotrichaceae was not established until 1825 by George Arnott. As currently envisioned, the Orthotrichaceae contain 22 genera, the largest genus being Macromitrium with over 350 species. Macromitrium is commonly encountered in subtropical forests. Here in California Orthotrichum is our largest genus although this fact has recently been altered as you will soon discover.

So what has happened to Orthotrichum? Through time various workers have focused on this family. Modern workers who have tackled the taxonomy of this genus include the Danish bryologist Jette Lewinsky (1948-1998). When she married and moved to Finland her later works were published as Lewinsky-Haapasaari. Much closer to home, Dale Hadley Vitt (1944-) did his Ph.D. dissertation on the genus Orthotrichum for North America under the direction of Howard A. Crum, and during his prolific bryological career, Vitt has produced great monographic revisions for several genera of the Orthotrichaceae, especially various treatments involving Macromitrium. However, not all bryologists have viewed Orthotrichum as a unified unit.

In 1879, S. O. Lindberg proposed transfering Orthotrichum obtusifolium to a new genus he called Dorcadion, and in 1908 Ingebrigt Hagen proposed the genus Stroemia to accommodate the very same species. In both cases, these two genera proved to be illegitimate because the names had been used previously to represent genera of flowering plants. Therefore, in their place came the new genus Nyholmiella Holmen & E. Warncke that appeared in Bot. Tidsskrift 65(1-2):179 in 1969 and was established to honor the Danish bryologist Elsa C. Nyholm (1911-2002) who produced the beautiful moss flora Illustrated Flora of Nordic Mosses, fascicles 1-4 (1987-1998). Nyholmiella was the first genus to be effectively carved out of Orthotrichum, and in this case three species remain transferred into it. Needless to say, this view was not widely accepted among the bryological community at that time who did not take kindly to having such a well-recognized genus altered. Yes, the lumpers and splitters debate has been going on for more than a century. However, subsequent molecular evidence has confirmed Nyholmiella as a genus worthy of recognition. Only one member of Nyholmiella occurs in California and this is N. obtusifolia.

In the last decade or so Spanish bryologists, primarily Francisco Lara, Ricardo Garilleti and Rafael Medina, have been advancing our understanding of Mediterranean Orthotrichum. Subsequently, their work resolved one of the ongoing taxonomic issues here in California. In the Catalogue of California Mosses by Norris and Shevock that appeared in Madroño 51(1), 2004, the name Orthotrichum tenellum was applied to a suite of very small corticolous mosses in California. The Lara, Garilleti and Medina team determined that the Orthotrichum tenellum complex comprises several species endemic to the Pacific Slope of North America and none of the western North American plants named as O. tenellum are actually that species. From this complex arose Orthotrichum franciscanumO. cucullatum, and O. norrisii.

For some time Orthotrichum lyellii with its distinctive reddish gemmae was viewed as an anomaly in the genus. Another species, Orthotrichum papillosum was placed as a synonym of O. lyellii but this was not a position taken by Norris and Shevock in the 2004 publication. A new genus has recently been created to accommodate O. lyelliiPulvigera Plášek, Sawicki & Ochyra appeared in Acta Mus. Siles. Sci. Nat. 64:171, 2015 but it only dealt with P. lyellii. However, O. lyellii var. papillosum as well as two other obscure varieties long placed as synonyms within O. lyellii were to be elevated to full species and transferred into Pulvigera. So not only do we have Pulvigera lyellii common throughout California, we gained two more species that are in this genus. This transfer again was done by Spanish bryologists when they determined that long ago ‘sunk taxa’ were in fact very distinct and that the genus Pulvigera diversified in North America. So now we can add conclusively Pulvigera howeiP. pringlei and P. papillosa to the California moss flora. This work appeared a couple of months ago by Lara et al. 2020 in Botanical Journal of the Linnean Society 193: 180-206. Pulvigera contains four species, and they are all known to occur in California.

The next transformation based on both molecular and morphological data nearly sliced Orthotrichum in half. The morphological feature used as a primary diagnostic step in most Orthotrichum keys is to separate taxa with stomates that are phaneroporous (superficial) from those with stomates that are cryptoporous (immersed). It is also the best morphological character distinguishing species of Orthotrichum (the cryptoporous taxa) from a new genus named Lewinskya F. Lara, Garilleti & Goffinet (the phaneroporous taxa) that appeared in Cryptog. Bryol. 37(4), 2016. So now Lewinskya contains 76 taxa. Here in California we have 9 species of Lewinskya. It is indeed fitting that this new genus honors the bryological legacy of Jette Lewinsky.

Orthotrichum norrisii cryptoporous stomata (Shevock 32529, UC 1933675)


Lewinskya holzingeri phaneroporous stomata (Norris 70467, UC 1649719)

Some Orthotrichum and Lewinskya are exceedingly rare species or are only known from type specimens so very little is known about them. In many cases they have simply been overlooked or access to such specimens was not readily available for study while floristic works were under development. It should not come as a big surprise that especially large genera are likely to be transformed and reconstituted as more members are systematically studied; more species receive molecular investigation, new monographs undertaken, and original source documents re-evaluated. Much of the ongoing alterations of genera and families has been collated and presented in the updated on-line Classification of the Mosses prepared by Bernard Goffinet and William R. Buck. Earlier versions of this classification system appeared in the textbook Bryophyte Biology by Shaw and Goffinet. This online version is a great reference document to see the current placement of genera among moss families. Another issue to be aware of is that of species placed in synonymy. In most cases there appears to be little or no information on why a particular species was relegated as a synonym or who made that determination. I have studied several mosses and some of the taxa placed in synonymy is indeed baffling, and in my view, in error. So do not just accept all synonyms without taking a critical look on your own. Some long discarded species will need to be brought back to life and much of this will be confirmed by molecular data sets. For example, this happened with Orthotrichum papillosum that was sunk into O. lyellii but now we know conclusively that they are both distinct taxa. Another species pair now recognized as distinct are O. rivulare and O. euryphyllum. I predict Orthotrichum rupestre (=Lewinskya rupestris) is another species complex with much cryptic speciation to unravel across its broad geographic range.

No doubt many mosses in California will likely have a new name in the future or go back to a name long out of use. Orthotrichum is but one example of these changes. I find this an exciting and fascinating time in bryology as we obtain a much better view and understanding of the evolutionary relationship among the mosses and how these taxa are organized into units we conveniently call species, genera and families. Nonetheless, there will continue to be differences of opinion on what taxonomic units to recognize and what to call them. Do we split up Grimmia further or keep it intact? Although the genus Schistidium was established by Bruch & Schimper in 1845, it took additional decades before most bryologists accepted this taxonomic split from Grimmia. Today, molecular data are helping to support these decisions more quickly than in the past when such taxonomic hypotheses were simply based on morphological traits. And of course other well-known and speciose genera have been at the forefront of this debate. BryumHypnum and Racomitrium are but three that readily come to mind and how they are addressed in various bryological floras. I guess you have figured out by now that I’m more often in the splitter camp especially when I can recognize these segregate genera by gestalt in the field.

Orthotrichum affine → Lewinskya affinis
Orthotrichum bolanderi → Lewinskya bolanderi
Orthotrichum holzingeri → Lewinskya holzingeri
Orthotrichum laevigatum → Lewinskya laevigata
Orthotrichum lyellii → Pulvigera lyellii
Orthotrichum lyellii var. howei → Pulvigera howei
Orthotrichum lyellii var. papillosum → Pulvigera papillosa
Orthotrichum lyellii var. pringlei → Pulvigera pringlei
Orthotrichum obtusifolium → Nyholmiella obtusifolia
Orthotrichum papillosum → Pulvigera papillosa
Orthotrichum pylaisii → Lewinskya pylaisii
Orthotrichum rupestre → Lewinskya rupestris
Orthotrichum shawii → Lewinskya shawii
Orthotrichum speciosum → Lewinskya speciosa
Orthotrichum spjutii → Lewinskya spjutii

The “Boss” of Mannia gracilis spores

—David Wagner

Not long ago I received a specimen to examine that was originally determined as Asterella bolanderi. The dry thalli were pretty hard to analyze but spores were present in the sample. I examined them in a water mount and quickly recognized the specimen as Mannia gracilis. I know it well from numerous Oregon collections. (It was treated as Asterella gracilis until a study in 2010 instituted the transfer.) The difference is a funny, amorphous bulge on the inner (proximal) face of the spores. This bulge is missing from the spores of A. bolanderi. The bulge in M. gracilis is not mentioned in any major reference I have consulted, including Schuster’s Vol. VI of Hepaticae and Anthocerotae of North America or Damsholt’s Manual of Nordic Liverworts.

Interestingly enough, there is a very similar bulge found in Mannia californica. Schuster describes this feature, which he calls a “boss.” On the other hand, M. fragrans, a widespread species in the northern hemisphere, lacks the boss as do all other species of Mannia treated by Schuster. Schuster’s figure of the boss is not well figured. The best source for appreciating the morphology of these spores is found on the web page of California Bryophytes managed by Paul Wilson ( This page has SEM images prepared by William Doyle. These are exquisite and should be more widely known. All bryologists in CNPS would do well to have this page bookmarked. Doyle’s SEM images of M. fragrans show the same tight reticulate morphology of the bulge in the middle of its proximal face but it does not bulge outwards.

I have been working for some time on making quality spore images with light optics using stacking software. These are not as detailed as SEM images but do exhibit all salient features and, unlike SEM, are in natural color. The Mannia gracilis spores presented a particular problem. On the one hand, spores tend to settle with proximal faces down in a water mount, obscuring the bulge. Then, dry spores do not have the bulge clearly visible in a fresh water mount, which is why they may have been overlooked. For the attached images, I soaked the spores in water with a wetting agent overnight, then infiltrated them with glycerine. The soaking caused the spores to swell, including the bulge. Then, glycerine has a much better refractive index for photomicrography. The first image is a composite of several fields of spores.

micrograph of spores

The second is a close up with the bulge indicated by arrows on the two right hand spores. These are not proximal views but side views that reveal the bulge best. The spore on the left displays the distal face with typical anastomosing ridges that are not completely reticulate.

micrograph closer up of spores

Now I have another project to work on for these long days sequestered in my home lab.

♥ ♥ ♥


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