Multi-Characteristic Descriptions of Camellia Cultivars for Long-Term Identification and Conservation

Martin F. Stoner[1]

California State Polytechnic University, Pomona, CA, USA
[1] Ph.D., Professor Emeritus, e-mail: mfstoner@gmail.com

Introduction

My research on heritage camellias in Hawaii (Stoner, 2011) has made me keenly aware of the crucial importance of careful and highly definitive descriptions of camellia species and cultivars.  While there can be confusion or argumentation over identification of a small fraction of over 200 species of Camellia, the prospect of matching collected specimens to previously reported ones in a field of over 5,000 cultivars is daunting.  There are additional difficulties involving very similar cultivars, overlapping descriptions and, in some cases, genetic and environmental variations.  In some field collections of flowers from the same plant, there can be significant seasonal variation in flower form or color.  To make matters worse, there is variability in the extent, quality and utility of existing descriptions, lack of photographs, and other problems.  In my Hawaii work, it has taken me nearly four years of multi-seasonal observation to convince myself as to whether four different red, formal double-flowered C. japonica plants are the same or different cultivars.  Now I am fairly convinced that three are the same, but I still am not sure if they match any reported cultivar.  Perhaps it is time for some molecular comparisons.

Another difficultly is the time it takes to seek comparisons in the form of photographs, live plants, or descriptions in rare literature.  On the positive side, the quest is fascinating.

All of this has created in me a deep concern and feeling of urgency that conservation of cultivars and species of camellias is greatly threatened by not only habitat or collection losses, but also by the generational changes in camellia enthusiasts and allied losses of recognition and other knowledge about cultivars that is not properly recorded for the future.  Particularly with regard to recognition, we need to confront some realities.

First, I have mentioned already the problem of many insufficient descriptions in publications.  This is minimally offset today by person-to-person communication (passing) of knowledge for supporting recognition, such as occurs between sages and novices at flower show judging or camellia society lectures.

Weakening awareness of, and diminishing abilities to identify, camellia cultivars, coupled with difficulties in maintaining collections of plants in botanical gardens, nursery foundation stocks, and other locations seriously threaten survival of historic as well as more recent cultivars,

I am proposing some ways of improving descriptions of cultivars that should simplify and expedite further identification over the long term.  I am also suggesting ways that those improved descriptions can be integrated into an efficient, cooperative, international system supporting long-term recognition, identification, documentation, and more complete and widespread conservation of camellias.  Cultivars are repositories of genes, a priceless resource.  We can work diligently to save what cultivars we can.  To do that we first need to identify them.

Principal Concepts and Values of Multi-Characteristic Descriptions

Most present cultivar descriptions concentrate on describing the basic flower form (e.g., single or peony form) and size, color, bloom season, and perhaps some brief information of leaf shape and size or plant growth habit.  These brief descriptions may be sufficient in the relatively short term; familiarity with more popular cultivars can be reinforced by frequent contact with the plants and by person-to-person teaching, as in flower judging or camellia club meetings.  But in the long term, such descriptions may be much less useful.  Major deficiencies of many brief descriptions are attributable to the lack of essential exactitude in describing characteristics as well as the lack of highly distinguishing features of the flower, other parts, or the plant itself.

More recently, there have been some efforts to be more detailed in descriptions, but there are still very weak descriptions being published.  Concerns regarding cost of publication quickly emerge, but some solutions to that concern are proposed herein.

Improved multi-characteristic descriptions I am proposing could still start with basic kinds of information as mentioned above; however, an effort should be made to search for and study typical features more carefully and to inject more precise, defining detail.  For example, imagine you are writing a description for a new hybrid or seeding.  Rather than simply writing “anemoniform” for the flower, note some distinguishing features of that form such as “anemoniform with center tightly clustered, narrow, 1-inch-tall magenta petaloids and no stamens.”  Rather than commenting “leaves elliptical,” indicate “leaves elliptical with very wavy margins.”  Rather than indicating “two-inch-tall, central column of stamens,” a closer look might reveal, “tall central column of stamens, narrowing abruptly at the apex and bearing kidney-shaped anthers.”  In yet another case, “very large leaves” could best be represented as “four-inch-long, obovate leaves with blunt-tipped, nodding acuminate apex.”   In all the above examples, the extra details are helpful but probably none or few would qualify individually as pivotal in distinguishing this camellia from fairly similar look alikes.  Consider how a person, two generations from now, who has never seen or heard of a particular cultivar, could distinguish the flower from 100 other similar ones using very simple descriptions such as “bright red semi-double; medium; with central column of stamens; ovate leaves; mid-season.”

At the heart of the Multi-Characteristic Description concept are two integrated functional components that work to produce a highly distinguishing description that facilitates and expedites identification of a cultivar.  Such a description is much more useful in rechecking and validating foundation stock in nursery collections, botanical gardens, clonal germplasm repositories, and in supporting other conservational purposes.

The two integrated, component functions described below are (1) Intensive, Exacting Observations Resulting in Highly Definitive Descriptions and (2) Multi-factor Corroboration of Identification by Co-occurrence of Distinctive Characteristics in Descriptions.

Intensive, Exacting Observations Resulting in Highly Definitive Descriptions

Observations of a specific camellia plant and its component parts to record detailed data should be intensive and exacting.   The crux of these observations will be used in a relatively short but very strong, distinguishing description.  This description, together with additional descriptive data, can be placed with photographs or other visual matter in a large electronic file and/or paper file.  The describer should observe the plant over at least one year for any useful growth-related features; the stability or variation of recorded characteristics; and seasonal changes.  Also, the describer should endeavor to observe the plant in various environments and geographic locations, especially to evaluate stability of characteristics and other notable features that could increase the value of the description.  Multiple observations can reveal missed features.

All described features should be recorded in precise detail, with careful descriptions of visible aspects in addition to measurements.  Molecular information, if available, could be included (or added later), particularly if it is of comparative use.  It is best to record and file all observations in the field or lab. 

Of upmost concern is detection of one or more unusual or possibly unique, highly distinguishing (“pivotal”) features.  Preferably these should be visually detectable (with a hand lens if necessary), rather than features requiring laboratory tests.  Pivotal features must be present routinely in collected specimens and be genetically stabile to be of high value in comparisons. Exactitude functions to greatly strengthen comparative identification of cultivars.

Multi-factor Corroboration of Identification by Co-occurrence of Distinctive Characteristics in Descriptions

Multi-factor corroboration of an identification is achieved by increasing the number of carefully selected characteristics that are moderately and pivotally distinguishing for a cultivar.  Co-occurrence of distinctive characteristics in a single cultivar greatly reduces the likelihood of confusion between apparently similar cultivars, provided that careful comparisons are made.  Just one pivotal feature, in combination with other features of a single cultivar, could validate an identification if other carefully described characteristics are moderately distinctive.  Two or more different pivotal features plus other distinctions in a single plant make it highly unlikely that a description will strongly fit more than one cultivar.  In my experience so far, when I find a very pivotal characteristic, such as proliferation of styles on a distorted ovary that is consistently produced, fine details of that feature tend to be reasonably consistent as well.  Tendencies in a cultivar for frequent variation in a specific feature, such as having peony and anemone form blossoms at the same time, is worthy of note.

Special Considerations

General Recommendations for Preparing Descriptions and Reviewing Registered Cultivars

Descriptions of morphological features, colors, and other visually detectable features of whole plants or plant parts; measurements of structures; descriptions of phenological or developmental characteristics; and anomalies or other highly individualistic distinctions are potentially useful.  Familiarity with the range of structures and variations seen in camellias will help the observer to better identify useful characteristics.  Surveys of named cultivars in botanical gardens, nurseries or other collections will help strengthen awareness and develop perspectives.  Participation in camellia society meetings and flower shows is also illuminating.  There is a wealth of information, including illustrations, available in diverse Camellia literature and via the internet.  The International Camellia Register and Supplement (Savige, 1993) and various editions of Camellia Nomenclature (latest edition 2009) and its Supplement for 1996 (Southern California Camellia Society) provide lists of cultivars.  The International Camellia Register is more exhaustive in coverage of cultivars and has more detailed descriptions.

Significance and Utility of Descriptive Characteristics 

In descriptions of Camellia SPECIES, attention is concentrated on features of the floral structures:  primary sexual parts (ovary, stamens), secondary or accessory parts (petals, sepals) and derivative parts (fruit, seed), all of which usually show consistent and sound comparative distinctions.  Less attention is given to the characteristics of vegetative parts such as leaves and stems because of their tendencies toward greater variability; although these are often described or illustrated to some extent to round out impressions of each species.  Some vegetative characteristics such as reticulated leaf venation can be fairly distinctive in some cultivar descriptions.

In contrast, both sexual and nonsexual (vegetative) characteristics are potentially useful in highly effective descriptions of CULTIVARS, providing selected features occur consistently in plants and are precisely described, based on intensive observation.  While some wild species can be brought into cultivation, most cultivars are cloned hybrids, cloned mutants of hybrids, or hybrids of cultivars and wild species. They tend to have more diverse blends of characteristics and anomalies probably attributable to their mongrel backgrounds and complex genetics.

Some additional basic insights into the biology of sexual and vegetative characteristics are appropriate here.  Sexual features and vegetative (non-sexual) features have decidedly different evolutionary backgrounds, goals and functions in plants.  Sexual characteristics have evolved and become more efficient over time to mostly serve long-term goals and functions, namely reproduction, genetic variation over time to aid in survival in a changing world, and, not least, survival itself.  Survival is a prime directive built into organisms!  Not surprisingly, sexual plant parts and mechanisms that benefit the directive are logically “conservative” features and typically subject to less variability over time.  It isn’t logical to entirely change an essential feature if it is working well.  Sexual characteristics are aimed at the “conquest of geological time.”  Sure, in camellias you may see minor floral variations in relatively “non-consequential” (non-antagonistic to survival or reproduction) features such as petal color or marginal shape, but the flower as a whole (basic layout and primary sexual parts) tends to be highly conserved and recognizable in wild types and useful to taxonomists, particularly in describing taxa above the cultivar level.  In the wild, Camellia species need good functional sex organs for survival.  Cultivars may lack sex organs or have non-functional parts, but they still survive and increase in number only by human-assisted horticultural cloning.

Vegetative (non-sexual) features such as leaves, stems, and roots are more concerned with the “conquest of habitat” (more immediate or short term concerns than goals for the “conquest of time”).  Relatively minor changes in vegetative parts can occur in shorter periods of time by driving forces of habitat change and selective survival within local populations.  Vegetative parts may also have physiological abilities that allow for immediate adjustments in a “real time” sense in the environment, such as leaves or stems turning toward light – or chloroplast populations increasing or concentrating in more illuminated areas in leaf cells in shaded plants.   Other “spontaneous” changes in vegetative characteristics could occur by mutation or hybridization. 

Utility of Molecular Testing

In coming decades, molecular distinctions between cultivars (involving comparisons of DNA, alloenzymes, etc.) will become increasingly useful and important in comparing and identifying cultivars.  Visible morphological and developmental features will remain very important in integrated, practical descriptions and identifications.

Efforts at molecular comparisons of cultivars are in early stages of development.  Some comparisons aimed at differentiating between closely similar camellia cultivars and in validating cultivar identifications have been done (Couselo et al., 2010).  Additional techniques are being developed (Chen & Nelson, 2006).  Coverage of cultivars using molecular techniques is extremely limited, so such data are of very limited value for use in descriptions and comparisons on a broad scale.  It appears that more standardization of techniques will be needed before molecular comparisons on a broad scale can be done.  Lastly, access to, and costs of, molecular comparisons limit their broad scale use.  As time passes, molecular data of direct descriptive and comparative use in cultivar studies could be included in electronic files.

Example Characteristics Useful for Describing and Identifying Cultivars

In Table 1, I have provided a short list of selected, specific characteristics or categories of features presented according to plant parts that have been or could be used to distinguish plants. A few examples of these characteristics are illustrated by actual photographs in Figure 1-2.

Hopefully these will inspire people to find other fascinating examples.  As a professor and plant pathologist, I have exhorted my students to become keen observers.  Practicing what I preach in studying camellias has revealed some amazing things that we generally do not notice when just casually enjoying the beauty of intact flowers.  Camellias in general are rich in diversity and quite variable.  It appears that hybridization and other genetic phenomena in the background of cultivars have resulted in many unusual and distinctive anomalies and other variations. Do not hesitate to dissect flowers when observing closely for possible hidden features.

Table 1:  Example Characteristics Useful in Describing and Identifying Cultivars.
(Characteristics should appear consistently in cultivar; all categories below imply unusual and very distinctive characteristics within context.) 
See Fig. 1 and Fig. 2 for related picture examples.

Fig.  1  Photographs of consistent, highly distinguishing characteristics of different camellia cultivars

Fig.  2 Photographs of consistent, highly distinguishing characteristics of different camellia cultivars. 

Ideas for Future Progress

Revision of Earlier Descriptions

Since descriptions of many old cultivars are sorely lacking in definitive detail, efforts to conserve such varieties must include better descriptions.  Before this can be done, in some cases, the valid cultivar (especially in confusing areas such as medium, red, formal doubles) matching the name of interest will have to be found and confirmed.  This may require some international cooperation to support first-hand comparison of potentially valid clones.  [This is the type of case where molecular genetic comparisons (Couselo et al., 2010) have already proved valuable in discerning the valid cultivar from look-alikes.]  Collected, valid clones of that cultivar can then be subjected to exacting Multi-Characteristic observations and improved descriptions prepared.  This will permit also the determination of which clone or clones are most typical, free of viruses or other systemic pathogens, and suitable for foundation stock in protected clonal repositories for conservation purposes and use by certified propagators who could in turn supply wholesale growers.   Qualified researchers may be able to secure plants directly from a repository.

As revised electronic or printed editions of The International Camellia Register (Savige, 1993) or Camellia Nomenclature (Southern California Camellia Society, 2009) and other treatises on cultivars are developed, efforts should be made to incorporate information from improved Multi-Characteristic descriptions.  Organized cooperation of organizations and individuals engaged mutually in beneficial efforts should assure and facilitate such revisions.

Uses of Electronic Data Systems

Files of data, if inputted and managed properly using carefully selected or designed software, could be utilized for more than storing descriptions of camellias.  Pre-planning for special uses should involve development of descriptive
character codes that could be electronically referenced, together with coded lists of known cultivars.  Revised or new artificial intelligence “association”-type programs could be used to create something functionally akin to a taxonomic key whereby someone trying to identify an unknown cultivar could input descriptive codes representing the characteristics of cultivar into the computer for a search.  The computer would display a list (hopefully not too long) of cultivars that closely fit the description.  (This assumes the existence of fairly comprehensive files of major named cultivars.)  The researcher could then survey the full information files for these pinpointed cultivars to further narrow the possibilities and perhaps specifically identify or validate the cultivar.

The computing power and information retrieval programs for this work exist today, but the difficult work will be to carefully develop the Multi-Characteristic files and allied descriptor codes by which searches can be done.  Right from the start of developing electronic files of named cultivar descriptions, careful cooperative consultation and holistic imagination should be done to envision a coding system that could “grow” as new descriptor codes (representing newly discovered pivotal characteristics) are needed, and more coded named cultivar descriptions are filed.  Codes for molecular data could be similarly searched as part of descriptions.

Such systems would be, or already are, useful to other crops or non-crop applications internationally. This encouragingly points to strong possibilities for governmental and/or business support, to systems sharing, and other cost-saving possibilities.  No doubt it would also involve considerable volunteer support for creating, searching, amassing, and coding data about named cultivars.  But the outcome would be very valuable to many endeavors.

Right now, a system like this, in miniature, could be developed for use by people working on restricted groups of camellia cultivars, as is the case with some molecular biologists studying Camellia species.  This might be a good place to create a prototype, because molecular biology already has electronic files and retrieval systems for genetic information.  Having electronic systems for broader applications would “complete the loop” for cultivar identification, description, and clonal germplasm conservation in support of many camellia-related pursuits.

International Cooperation

Most, if not all, of the endeavors, present or future, that have been discussed here can be facilitated by strengthening communication and multifaceted cooperation of camellia hobbyists, nursery people, students, and professional individuals affiliated with arboreta and botanical gardens, universities, departments of agriculture, governmental or private clonal germplasm repositories, various plant industries, camellia societies, computer information services, and others.  Accomplishing big aspirations can be made more manageable by the efficiencies of joint efforts.  Volunteers will be an extremely important component.

Literature Cited

Chen, L., and Nelson, M. 2006. Optimization of the RAPD marker techniques in Camellia. In: American Camellia Yearbook, American Camellia Soc., Fort Valley, Georgia, USA.
Couselo, J. L., Vela, P., Salinero, C., and Sainz., M. J. 2010. Characterization and differentiation of old Camellia japonica cultivars using simple sequence repeat (SSRs) as genetic markers. International Camellia J., 42: 117-122.
Savige, T. 1993. The International Camellia Register, Vols. 1, 2 (and later Supplement). International Camellia Soc., Sydney, Australia.
Southern California Camellia Society. 2009. Camellia Nomenclature. King. B. D., Belcher, B., and LeFebvre, A., Eds. (see also: 1966 Camellia Nomenclature Supplement devoted to mostly historic C. japonica and C. sasanqua cultivars).
Stoner, M. F. 2010. Identification, history, cultivation and conservation of heritage Camellias in Hawaii. International Camellia J., 42: 46-49.