IS THIS PLANT A HOAX?
A LECTURE IN HONOR OF OTTO RICHTER
Arthur O. Tucker and Michael J. Maciarello
Department of Agriculture & Natural Resources
Delaware State College
Dover, DE 19901-2275
Otto Richter is well-known to us as a founding director of IHGMA (now IHA). Otto was born in 1918, and prior to immigrating to Canada in 1953, he operated a nursery in Austria. He and his family began to grow and sell herbs in 1969 at a former location in Locust Hill, Ontario, later moving to Goodwood; the first herb plant and seed catalog was published in 1970. Besides selling herb plants and seeds and supplying fresh herbs to elite restaurants until his retirement in 1984. He was also active in community beautification projects and organized public displays at garden shows in Toronto and at the 1980 International Floralies Exhibition in Montreal. He died December 17, 1991, leaving behind his wife (Waltraut Klonz), four sons (Volkmar, Herbert, Conrad, and Otto), a daughter (Christel), and six grandchildren. Richters’ is now under the management of Conrad Richter.
Consumers have always been impressed by Richter’s catalog. Richters has offered a full array of herbs by mail-order, including the more unusual ones, and each herb has been summarized in a paragraph. Otto also made a very serious attempt to accurately label his plants; he sought our advice several times by mail before we actually met him in person.
The 1993 Richter’s catalog asks of the ‘Citrosa’ geranium "Is this plant a hoax?" Rather than trying to make a quick buck, Richter’s actually takes a stand and states the few facts known about this plant.
P.T. Barnum may or may not have noted the birth of 60 suckers every hour, but, even in a recession, people are willing to pay good money for "tarragon" seed and "true oregano" seed that produces plants that smell like shoe leather. Worse yet, we find that people will actually come back again to buy more! "Well, then, what do you expect", as one English gourmet asked us, "with a public that does not know the difference between cassia and true cinnamon?" Americans want to trust the integrity of their suppliers, so we, as an educated and "enlightened" association, should ensure that beginners are not mislead and these mistakes are not propagated, literally and figuratively, into eternity.
’Citrosa’ Geranium (a.k.a. Pelargonium ‘Van Leenii’)
The ads claim that "Citrosa Mosquito Fighter is the result of a revolutionary new breakthrough from a Dutch horticulturist. It was genetically created by crossing tissue cultures of an African Geranium with the Grass of China in sterile laboratories." "He used a technique called protoplast isolation and fusion whereby through genetic engineering, Mr. Van Leenen took a specific geranium and "married" it to Cymbopogon Nardus creating in effect a new and different utility plant." "It is the grass that contains citronella oil, the active repellent ingredient. The Geranium gives it the ability to effectively release the blackflies and most biting insects." Furthermore, "These days, everyone’s trying to do their part to help the environment an slow the eradication of the ozone layer. The Citrosa eliminates the need for aerosol sprays that are a leading cause of ozone depletion. And now, there’s no need to apply greasy chemical lotions to your skin." In Canada, this plant is marketed as "Citranium (Pelargonium x Blandfordianum [Andr])x", while in Australia it is sold as "Mossie Buster".
From published reports, the oil of Ceylon citronella grass (Cymbopogon nardus) has an average of 20% genial, 14% citronellal, and 12% citronellol and gernial acetate. The oil of Java citronella grass (C. winterianus) has, on the average, 22% gernial, 22% citronellal, and 16% citronellol and gernial acetate. By gas chromatography.mass spectrometry in our lab, the oil of ‘Citrosa’ geranium has, on the average, predominantly 39% gernial and 11% citronellol. The citronellal content is only 0.09%! Compare this, if you will, with the common rose geranium (Pelargonium ‘Rose’), which as 15% gerniol, 25% citronellol and gernial acetate, 10% cintronellyl formate, and no citronellal. ‘Dr. Livingstone,’ another rose geranium, does have 9% citronellal, though.
The ads also claim "During the tests it was further proven that also present was Citral which makes up 70% of the Cohcin Lemon Grass oil, a well known mosquito repellent from the East." Nor citral is actually two separate compounds, gernial and neral. We have not been able to find any neral, and the gernial content is only 0.34% in the essential oil.
Thus, ‘Citrosa’ does not have any unique compounds not found in other species of Pelargonium. Actually, if you wanted to grow a high citronellal plant, then selected forms of lemon balm (Melissa officinalis) may have up to 38% citronellal.
What about the claim that this is a hybrid of "an African Geranium with the Grass of China" from tissue culture? We cannot define any character of the current ‘Citrosa’ geranium which is unique to a Cymbopogon species. Actually, the morphology of ‘citrosa’ is indistinguishable form green reversion that we have collected from ‘Grey Lady Plymouth’. According to Dr. Barry V. Charlwood, the Director of Biotechnology at King’s College London and a leader in the tissue culture of Pelargonium, "Although protoplast fusion is easy to carry out, selection of the required heterokaryon would be extremely difficult, and protoplast regeneration of fragrant Pelargonium is in our hands impossible." Dr. Richard Craig, Professor of Plant Breeding at Pennsylvania State University, has also noted in a letter that gene insertion would have been impossible with the technology available in c. 1975.
What about the claims of ‘Citrosa’ as a mosquito fighter? Dr. G.A. Surgeoner and J. Heal at the University of Guelph in Ontario tested the effect of ‘Citrosa’ and lemon thyme (Thymus x citriodorus) against the biting activity of Aedes aegypti mosquitoes. They found that the whole plant of ‘Citrosa’ geranium DID NOT provide significant protection against mosquito bites (yet the ads state "The chemicals act to block the mosquito’s sensory apparatus so that it can not detect mammals. Mosquitoes may be in the area around the plant but they can’t detect you.") Crushing of ‘Citrosa’ leaves on the hand and wiping one’s hand through the ‘Citrosa’ plant appeared to provide about 30-40% repellency. However, Surgeoner and Heal found that crushed lemon thyme produced 62% repellency! Compare this with commercial Deep Woods Off, which produced 90.4% reduction in biting activity.
Peppermint (Mentha x piperita) has been shown by resynthesis and other intersecting evidence to be a hybrid of spearmint (M. spicata) with watermint (M. aquatica). Since this is a hybrid of two "good" Linnaean species with different chromosome numbers, the flowers are 99% sterile. Now, that is not absolute sterility, but 99% sterility is enough to prevent any company from offering peppermint seed commercially! Back in 1967 we grew all the "peppermint" seed that was offered by various sources on the international market. All these seeds grew to a rather rank form of spearmint. We wrote letters to all the companies. Those that did respond replied that their supplier in West Germnay verified that their "peppermint" seeds were true to type and the case was closed. Besides, who were we to challenger their authority? We wrote back that their seeds were still spearmint seeds and all they had to do was check it themselves. We also enclosed detailed botanical keys and copies of the herbarium specimens. Yet, we still see "peppermint" seeds listed in books, catalogs, and nurseries. When will they ever learn?
We had one company ask us how true peppermint seed could be offered. Well, that is possible by crossing a high-menthone clone of spearmint with watermint, but that would require a lot of hand labor and the progeny would be rather variable. Another possibility is to offer dehydrated, pelletized callus derived from tissue culture, but that would be very expensive and not really worth the effort.
"Doesn’t this have a wonderful chocolate aroma?" asked an herb grower. "No," we replied, "it’s ‘Mitcham’ peppermint and we don’t smell any chocolate." This is another example of good old-fashioned hype and the power of suggestion. The plant we call "typical" peppermint exists in two forms, white peppermint (M. x piperita var. officinalis) and black peppermint (M. x piperita var. piperita). ‘Mitcham’ is the leading cultivar of the latter and the one usually encountered in the herb trade, whether it be called "chocolate mint", "blue balsam mint", or whatever (we have also encounterred white peppermint offered as "chocolate peppermint"). Because of extensive propagation since black peppermint was first cultivate din 1750 near Mitcham, England, some very slight variability has occurred, and ‘Mitcham’ is not a clone. This is not unusual; slight variability is often encountered under identical cultivar names for many plants. However, none of this variation is significant enough to deserve a separate cultivar name (actually the term grex, a collective epithet from the Latin for swarm or flock, would be appropriate here). The A.M. Todd Co. has selected Verticillium wilt-resistant clones of ‘Mitcham’ (’Todd Mitcham’ and ‘Murray Mitcham’) by gamma-irradiation for commercial production, but these oils are similar to the original ‘Mitcham’ cultivar. In addition, the pyrazines and other compounds which typify chocolate aroma are just not found in significant quantities in peppermint. We think the confusion has arisen because many chocolate-mint candies and liqueurs prompt the consumer to associate a peppermint aroma with chocolate.
"Curly Mint" Seeds
Hmm, curly mint... now there’s a good case of caveat emptor. Crisped leaves in Mentha are under the control of at least one gene, and another gene probably controls the degree of crispness. Crisped mints are known in spearmint and peppermint, its hybrid. Both these have been called curly mint, but the former does not breed true from seed and the latter is intensely sterile. The best scam of "curly mint" seeds that we encountered was one packet labelled curly mint on the front and peppermint on the rear accompanied by a picture of the green pineapple mint, M. Suaveolens. It germinated to a rank, plain-leaved spearmint! Other packets of "Curly mint" germinated to M. Suaveolens. If you want to gamble, here’s a way that’s cheaper than Las Vegas or Atlantic City.
"Dr. Anderson’s Mint"
Another mint which has come to us is supposedly a hybrid of peppermint and spearmint. The story goes that this hybrid was originally made by one of the premier mint geneticists, Dr. Mabel Ruttle Nebel. Duplicates of her collection were sent from New York to the great Russian economic botanist, N.I. Vavilov, but unfortunately we have since learned that most of Vavilov’s collection perished during the same winter that Vavilov perished in a Siberian salt mine (his pioneer research on agricultural germplasm was not socially acceptable to Stalin). However, a peppermint-spearmint hybrid was supposedly sent to the Missouri Botanical Garden, where it acquired the name of "Dr. Anderson’s Mint". The plants that came to us, directly from Dr. Edgar Anderson at the Missouri Botanical Garden, were not a peppermint x spearmint hybrid but rather a selfed spearmint. Detailed chemical analysis also revealed no significant content of menthol, menthose, or piperitone or the isomers of these peppermint-scented compounds. Yet, we have people swear to us that they can smell both peppermint and spearmint in this plant after being told that it was supposed to be a peppermint-spearmint hybrid. Presented point blank, with no coaching, however, they first say that it is a spearmint. Funny what the power of suggestion can do... Now, peppermint is extremely sterile, and any hybrid would be expected to be extremely rare and probably rather weak. We suspect that the original plant was encroached upon by an adjacent plant or seed.
There is also another rule in essential oils that you cannot have both spearmint and peppermint odors in the same plant. One clone of M. x gracilis, called redstem applemint, has apparently never heard of this rule, though, and is really a "doublemint". This is a very rare exception to the rule because of a very high chromosome number that causes an apparent breakdown in the genes controlling the biosynthetic pathways.
"French Tarragon" Seed
Artemisia dracunculus is a circumboreal species. That is to say, this species is found in Asia, Europe, and North America. A species with a wide geographical range would be expected to have some variation, and A. dracunculus does not disappoint us. Seed-propagated plants from Asia (Russian tarragons) have been shown to have either sabinen and transisoelemicin or sabinene and elemicin, giving them a piney-balsamic odor. From the scant evidence that exists, we know that sometime around the Middle Ages someone found a form with a different scent, and this was eventually propagated throughout Central Europe. This has come down to us today as French tarragon. This clone is weak, hardly flowers, and never produces seed, but the oil is high is estragole (methyl chavicol), which is also found in basil (Ocimum basilicum). Since this is a manmade (or womanmade?) selection of A. dracunculus, it is given a cultivar name, ‘Sativa’. Have you purchased "tarragon" seeds? When we first started out growing herbs, we too fell prey to the seed catalogs. The plants really grew well, and not knowing from the text books of the time what true French tarragon was supposed to smell like, we accepted it as something for cooking. Yuck! Don’t buy tarragon seed to acquire plants for cooking! What you get are the Russian tarragons. These might be nice for formulating a new masculine cologne, but for cooking, well, old leather shoes would do just as well...
’Munstead’ Lavender Seed and Lavandin Seed
How many times have you encountered advertisements for ‘Munstead’ or ‘Hidcote’ lavender seed? Too many, we’re afraid! Like French tarragon, ‘Munstead’ and ‘Hidcote’ lavenders are vegetatively propagated clones. You must propagate these clones by cuttings or layerings; seed propagation would produce "Munstead-derived" or "Hidcote-derived" plants, not the true lavenders selected by Gertrude Jekyll or Major Lawrence Johnston.
’Munstead’ is even more of a problem. ‘Munstead’ lavender was never mentioned by Gertrude Jekyll in any of her writings, so we don’t have an accurate description directly from her. However, from period references and reliable nursery sources, the true ‘Munstead’ is a dark-flowered lavender similar to ‘Hidcote’. what is often pawned off on the Americans as ‘Munstead’ is ‘Compacta’. Why not substitute ‘Compacta’ for ‘Munstead’? Well, ‘Compacta’ has a much sturdier growth and is easier to propagate, but the flower color is a light lavender, not the dark purple that it should be.
We have also been asked to supply lavandin seed. Here is another interspecific hybrid: lavandin, Lavandula x intermedia, is a hybrid of lavender (L. angustifolia) x spike (L. latifolia). It has true hybrid vigor and is resistant to any of the scourges that plague lavender. However, being an interspecific hybrid, it just is not very fertile and rarely sets seeds. You cannot buy seed of ‘Dutch’, ‘Grosso’, ‘Grappenhall’, or ‘Hidcote Giant’, so be wary if it is offered.
Oregano seed is another great disillusionment for the beginning herb gardener. Yes, we’ll admit it... we fell prey to the propaganda too. Now that we are much wiser we want to preach: if your "oregano" has pink flowers and bracts and lacks the odor of the oregano on the grocery shelf, don’t bother to cook it. The true Greek or Turkish oregano is Origanum vulgare subsp. hirtum. This has white flowers and greenish bracts with the creosote-like odor of the real thing. The pink-flowered plant is really wild marjoram, O. vulgare subsp. vulgare. It’s fine for dried flowers and is extremely vigorous, but it just doesn’t hack it for pizza. Worse yet, we have purchased seed labelled Coleus amboinicus (correctly known as Plectranthus amboinicus), the oregano of the Caribbean and southeast Asia, only to have it germinate to wild marjoram. Beware!
Kazanlik Damask Rose
The damask rose, Rosa damascena, has been cultivated in Bulgaria and adjacent regions for a long time, possibly back to King Midas. Both seed and vegetative propagation have occurred repeatedly, as so the roses cultivated today in the Kazanlik Valley of Bulgaria are not ramets of one clone. The appellation of ‘Trigintipetala’ to designate on clone of the Kazanlik damask rose dates back to a description by Dieck in 1889.
Over 10 years ago we attempted to locate the Kazanlik damask rose in the nursery trade in North America and Europe. Every nursery sent something different. A leading nursery in California sent ‘Alika’, a cultivar which dates back to 1906, when it was brought back from Siberia by N.E. Hansen. Worse yet, it isn’t even a damask rose! Again, we received the curt reply that this nursery was right we were dead wrong. From Canada and Great Britain, we received ‘Prof. Emile Perrot’, a clone which was gathered from commercial field in Iran and introduced by Turbat in 1931. A similar rose is ‘Gloire de Guilan’, which was gathered from commercial fields in the Caspian provinces of Iran by Miss Nancy Lindsay and introduce by Hilling in 1949. Finally, from a nursery in Denmark, we found the clone matching Dieck’s original description. This is ‘Trigintipetala’, but it is only one of the Kazanlik roses (actually, like ‘Mitcham’ peppermint, ‘Tringintipetala’ damask rose might be better designated as a grex too).
Harriet Flannery Philips, in her monumental thesis on the genus Thymus, found that the thyme that most people want for cooking is a high thymol race that has the earliest legitimate name of T. vulgaris ‘Narrow0leaf French’. This is the same thyme sold variously as German winter or French summer thyme. The trouble is that this cultivar name designates a seed line and actually embodies a wide range of variation in morphology as well as thymol content. While commercial seed propagation of this cultivar should produce rather uniform seed, most plants are female, which promotes outcrossing to other thymes that bear fertile pollen. Like basils, thymes can be highly promiscuous and readily cross with races with different chemistry and morphology. We hope that, in the future, some enterprising herb grower will select vegetatively propagated cutivars of high thymol T. vulgaris. We have had plants sold to us as "French thyme" that had no business being in any kitchen, must less a French one.
Flowerless and Seedless Patchouly
Back about 15 years ago we attempted to locate patchouly in the trade. No North American nursery offered it. A scentless, large-leaved plant which hardly every flowers for us was offered in some catalogs; we have since identified this a Pogostemon benghalensis (P. plectranthoides). Many herb growers have a poor impression of patchouly as a plant because of this substitution.
In the seed list of a French botanic garden, we saw P. heyneanus, the false patchouly. We jumped at the chance to obtain seed and it germinated well. We introduced this via some favorite herb nurseries and later had it offered back to us by a scientist as the "true" patchouly "which never flowers". We replied, "Well, that’s strange, we grew it from seed ... we wonder where the seed came from if it never flowers..." Later on, at an extensive American houseplant nursery we found the true patchouly, P. cablin. Both the false and true patchouly flower well in the short days of fall/early winter and set seed for us. We suppose that the story of the flowerless and seedless patchouly has arisen because, near the Equator, many temperate to subtropical member of the mint family, Lamiaceae, refuse to flower under equal days and equal nights. A very rugose form of spearmint (offered in the trade as ‘Kentucky Colonel’) is like this. Wherever the Conquistadors trampled cultures, from Central and North America to the Philippines, they left this clone of spearmint behind in their footsteps. In Guatemala and the Philippines it refuses to flower and often appears as a sterile voucher for floras of the area.
We guess that the overall lesson of this is "You get what you pay for", so beware the offering of those very cheap herbs where no one knows one herb from another. Seek out reliable, knowledgeable suppliers. Be eternally vigilant. If the plant(s) do not agree in the flavor(s) and aroma(s) with what you expect, then question your source(s). If they look at you as if you were speaking a foreign language or tell you to "Get lost", then probably you know more than they do. Consult leading textbooks, and , if possible, search out period references to find accurate descriptions. Ask questions of leading researchers. Finally, write letters of concern to your supplier(s). Maybe if enough people write about "peppermint" seed, someone will finally get the message!
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