Botany Boy – Page 8 – Plant Encyclopedia

January 31, 2012April 4, 2018

Crocus sativus, the saffron crocus

The world’s most expensive spice, saffron, is produced by the saffron crocus, Crocus sativus. This intriguing and lovely flower’s story is intertwined with a human history that spans no less than 3000 years. In truth, it does not exist naturally anywhere, but rather is a sterile triploid cultivated through the centuries for its deep orange-red style and stigmata – the only part of the plant that is used to make the spice saffron. In addition, it is a welcome plant to any garden that meets its basic needs.

Crocus sativus flowers — Saffron crocus is an autumn crocus, flowering in October and November.

Crocus sativus bulbs are not true bulbs, but rather corms that closely mimic tunicate bulbs, complete with a dry outer sheath or tunic. In mid fall the leaves begin to sprout and grow just before the flowers emerge, or sometimes just after flowering. The blue-green leaves are long, thin and grass-like, growing up to 30 cm long, and have a lighter green vein down the middle. Each corm supports 5-10 of these. The leaves remain green throughout winter, dying back in spring. The above ground plant is fully dormant all summer.

The flowers open simultaneously. Each is around 6 cm across, and bears 5-6 broad lilac-purple petals with darker veins. The style is three pronged with each terminating in a stigma – the female part of the flower. The bright yellow anthers, also three in number, bear pollen, yet it is sterile, so no seeds can be produced. C. sativus is a autumn crocus, with flowering commencing in late October into late November depending on location and weather conditions.

The origins of C. sativus are not well known given its long history in cultivation. It is thought to be a selectively bred form of the naturally occurring C. cartwrightianus, a native of Greece and the Cyclades, an island group in the Aegean Sea. This species however has smaller flowers and the style/stigma lack the flavor of C. sativus. Unlike its triploid cousin, it is seed producing.

Today saffron crocus is grown across the world in any suitable climate. While it makes a lovely flowering bulb for the garden, it is mostly grown for the valuable spice, saffron. It has been grown for this purpose throughout much of Europe, the middle east, India, China, and even New Zealand and the USA. Today, Iran is the largest producer, yet Spain is the largest exporter. To this day no spice by weight is more expensive than saffron.

Like many natural herbal products, saffron contains a wealth of aromatic and volatile chemicals, giving its flavor and smell, as well as nonvolatile substances, such as carotenoids, that provide color and flavor. One of saffron’s most celebrated constituents is safranal, a volatile oil that furnishes most of its aroma. The spice is dried and must remain so to preserve this exotic cocktail of chemicals, therefore it must be kept in well sealed containers.

Crocus sativus corms — Crocus sativus bulbs are not true bulbs, but rather corms. Each lasts just one growing season, but can be replaced by many more.

Throughout its history saffron has been used as in dyes, in perfumes, in medicines, in body washes, as a narcotic, in aphrodisiacs, as an antidepressant, in potpourris, in make up, and of course as a spice, both coloring and flavoring all manner of foods and spirits. While historical use of saffron for a wide range of ailments is well documented, more recently it has been studied for possible anticarcinogenic and antioxidant properties.
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January 25, 2012April 6, 2018

A shield fern of southern Japan, Ctenitis maximowicziana

The warm temperate forests of southern Japan are home to a shield fern who’s most notable feature are the scales that cover its long stipes. This fern is so scaly in fact that they have earned it one of its Japanese names, the grey haired fern. The newly emerging croziers come up like a ball covered in so many of them that indeed it does look like the head of an odd white haired creature.

Ctenitis maximowicziana crozier — The emerging crozier of Ctenitis maximowicziana looks like some odd white haired creature on the forest floor.

Ctenitis maximowicziana is a medium sized to large evergreen fern growing from a short, creeping rhizome. The fronds are few (usually five or less) and ascend in a graceful arc. They are a light green color and three times pinnate. Each is from 50-100 cm long and 30-50 cm wide. The stipe accounts for one quarter of the length of the frond and is covered in large white and brown scales. These continue up the rachis nearly to the frond’s end, and also extend out onto the pinnae. The sori are round and are in pairs around the vein (called the costule) of each pinnule. Plants occur in small groups or singly.

This fern is found in the warmer regions of Japan from Honshu (most commonly in the Kanto region and westward, but with a northern outpost in Akita Prefecture), Shikoku, Kyushu, and the islands south of Kyushu including Okinawa. It is also reported from Taiwan and China. It seems to prefer moist ravines near water, but not at the water’s edge. This lovely woodland fern is found in both natural forests and in conifer plantations from 300-500 meters elevation on Kyushu.

Without a doubt, the most outstanding feature of this shield fern are its scales. From the time the croziers emerge in spring and throughout the frond’s life, the numerous lovely white and brown scales of the stipe and rachis are undeniably attractive. In spring the emerging crozier is brilliant lime green and literally covered with these, creating a unforgettable image. The scales brown with age and look best in the spring. Though not uncommon in Fukuoka, this fern is not frequently seen either, occurring in scattered areas. Without a doubt, this is one of Fukuoka’s most beautiful ferns.

Ctenitis maximowicziana in habitat — The fronds of Ctenitis maximowicziana hang in a graceful arc. The stipe and rachis are completely covered in white and brown scales that have earned it one of its names in Japan, the grey haired fern.

Ctenitis maximowicziana stipe — The scales up close.

The genus name Ctenitis means “comb” from the Greek word kteis. The species epithet, maximowicziana, is in honor of Carl Johann Maximowicz (1827-1891), a Russian botanist and curator of the Saint Petersburg Botanical Gardens. This fern is in the shield fern family, Dryopteridaceae, and is placed in the genus Dryopsis by some authorities. In the field it may be confused with another fern, Thelypteris torresiana, but that species lacks the tell tale scales of C. maximowicziana.

The Japanese name, kiyosumihimewarabi, means “noble princess bracken” from the words kiyosumi meaning “pure or noble”, hime meaning “princess”, and warabi the Japanese word for bracken fern. Yet again another obscure name. It also has an alternate name, shiragashida, coming from the word shiraga meaning “white or grey hair” and shida meaning “fern”, a reference to the white and brown scales found on the stipe and rachis. At least that makes sense!

Ctenitis maximowicziana spores — The sori of Ctenitis maximowicziana occur in pairs along the costa of each pinnule.

I’ve never tried this one before, but I suspect it shouldn’t be that challenging in a moist and shady garden. Given its distribution, it should be cold hardy to USDA zone 8-10 (perhaps a bit lower with adequate protection and careful siting).

As with many obscure Asian species, this woodland fern is virtually unknown in cultivation in the West. In truth, it is little known in Japan, except by fern enthusiasts, and is never seen as a garden subject. That is too bad since this graceful fern would be a great addition to warmer woodland gardens the world over.

January 23, 2012April 4, 2018

Two species tulips for hot climates

Central Asia is home to two species tulips that are remarkably resistant to hot summers and conversely cold winters. They are respectively, Tulipa ‘Little Beauty’ and Tulipa clusiana v. chrysantha. Moreover, both seem quite happy to grow and flower, and even increase over time with little maintenance in the hot, wet summers of southern Japan where I live. These two flowering bulbs are a must have in any suitable garden.

Tulipa 'Little Beauty' clump — *Tulipa ‘Little Beauty’* certainly lives up to its name. The flowers are borne in small clusters and open all at once, giving a stunning display despite this plant’s dwarf habit.

While both are commonly available in the trade, their naming is a bit confusing. T. ‘Little Beauty’ is a cultivar that has been listed as a form of T. hageri by some, T. humilis by others, as well as T. pulchella (a plant often considered a form of T. humilis). Variation within T. hageri and T. humilis is extreme, making the situation even more confusing.

T. clusiana has two color forms, white and yellow. The outer surfaces of the tepals are a lovely reddish-purple, giving flower even more interest. The yellow form is known as var. chrysantha and it is this plant I have experience with in the garden. Again, the naming of this tulip has been confusing with some considering it a yellow variety of T. montana, and sometimes it is sold under the name T. chrysantha.

Naming aside, both are lovely and rewarding garden plants. T. ‘Little Beauty’ is an extremely dwarf tulip, standing not more than 15 cm tall. Each growth offers a cluster of large, long lasting flowers borne on short, stout stalks. Each one is up to 6 cm across. The outer part of the tepals (the collective term for both sepals and petals) are a lovely reddish-purple suffused with varying degrees of pink. The center is a rich blue with white edging. Flowers open en masse and offer a stunning display.

T. clusiana v. chrysantha is no less stunning a flower, though the plant is taller, up to 30 cm or more. Each growth sports a single flower, but in a mass they are truly something to behold. While the outer surfaces of the tepals are strongly colored orange-red in this form, when the flower is fully opened and viewed from above it is the purest of yellows throughout, including the stamens and pistol. The flower stalks are quite a bit longer and thinner than in T. ‘Little Beauty’ and more subject to damage from high winds or rain.

Both plants are highly sensitive to sunshine, or the lack thereof. On overcast days the flowers close up totally. In the case of C. clusiana v. chrysantha that makes the red coloration more evident. Once the sun comes out, both open fully, showing their stark beauty.

The bulbs look much like any tulip bulb, but are much smaller, not more than 4 cm in diameter. These are true tunicate bulbs with a outer layer of dried sheath-like scales and embryonic tissues within that develop into the leaves and flowers. The leaves of both species are nothing special to look at – again, very tulip looking, light blue green color, but more narrow than the large hybrids. The leaves of T. ‘Little Beauty’ grow more prostrate to the ground than T. clusiana. The ornamental value of them is limited and their brief appearance (only about 2 months) doesn’t give you much time to see them anyway.

Tulipa 'Little Beauty' flowers — The flowers of *Tulipa ‘Little Beauty’* remain somewhat cupped even in the full sun.

Tulipa clusiana v. chrysantha flowers — *Tulipa clusiana v. chrysantha* is very responsive to the sun, opening and closing depending on its intensity. Here the flowers are half open in the weak morning sun, revealing the orange-red coloration of the outer tepals.

These plants are from south central Asia, an area with hot, dry summers and fairly severe winters. Flowering commences early in southern Japan, usually starting in early April. Depending on the weather, each flower can last for a week or more before fading. The leaves stay green for perhaps 6 more weeks and go totally dormant by late June, right in time with the onset of Japan’s intense monsoon rains. The plants remain out of sight until the following spring when they again make their brief appearance.

This does not mean they are totally dormant, just that the leaves are. While it is said that they prefer drier, hot conditions in summer to do well, in my experience, both weather out Japan’s monsoon without any trouble. Some years the monsoon can last up to nearly two months and over a meter of rain can fall in that short time. I have never lost any to rot during this period. I can’t say this is the optimal way of growing them, but they don’t seem to be adversely effected either. I have heard that they should not be planted in cold, wet soil since this invites rot.
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January 10, 2012April 6, 2018

Japan’s largest twayblade orchid, Liparis kumokiri

A close cousin to Liparis krameri is L. kumokiri. It shares many attributes with that species including its overall habit as well as habitat choice. I haven’t heard of any reported natural hybrids between the two, but it is quite likely, and such plants would be hard to distinguish from the parents. Their differences lay mostly in the flower shape and color, as well as L. kumokiri being on average a far larger plant with broader, ovate leaves. Out of flower though, one could easily be mistaken for the other.

Liparis kumokiri habitat with flowers — This flowering plant of *Liparis kumokiri* is growing on the top of a mountain overlooking Fukuoka City at an elevation of 730 meters. Fukuoka Prefecture, Kyushu, Japan.

Liparis kumokiri is a deciduous woodland perennial orchid. A pair of broad glossy leaves ascend from a pseudobulb that sits at ground level. The leaves are veined with the center vein being the most prominent. The leaf edges are flat or undulating, giving the false impression of serrations. They are a bright green and completely hairless; 7-15 cm long and 4-10 cm wide. The pseudobulb is round, but somewhat compressed, and 2-4 cm in diameter.

From the center of the leaves the branched less flower stalk grows to a height of 10-25 cm and supports anywhere from 5-20 bright green flowers. The flowers are typical looking for a Liparis, but give the impression of being rounded. They are about 1 cm across. The broad lip is strongly recurved. The sepals are arranged in a nearly perfect triangle while the petals are wispy almost hair like affairs and point backwards strongly. The column looks almost stalked. One interesting feature is the shape of the flower stalk – it has four distinctly flat sides so that the cross section would produce a square shape much like the stems of plants in the mint family. Like every other part of this plant, the seed pods are bright green and are held vertically.

Liparis kumokiri flowers — The flowers of *Liparis kumokiri* are unremarkable and not more that 1.5 cm across. Cultivated specimen.

Like its near relative, this twayblade orchid is found throughout Japan in moist woodlands and mountain forests, even up to the subalpine zone in grasslands and thickets. It flowers anytime from May in the south to July in Hokkaido. In the Fukuoka area it is limited to higher elevations, not below 650 meters or so. It is possible that L. kumokiri is a variant of the wide ranging L. campylostalix which is found from the subtropics of Indochina clear up to Siberia!

I first saw this orchid in a nursery in Fukuoka City. They had about 50 plants all just recently out of flower. Of course I couldn’t resist and I bought two. I had read that this species is actually quite common in Japan, but up to that point had I never crossed paths with one. In late July 2006 I finally got my chance. I was walking a high ridge line (about 850 meters elevation) and to my left was a lovely forest just screaming ORCHIDS!, so I went off trail for a hunt. I was soon rewarded with a large Liparis plant. At first I thought it was L. krameri, but closer inspection showed it to be this species instead. A search of nearby areas revealed several dozen plants, many of them in small clumps. Some individuals were huge for a Liparis with leaf spans up to 30 cm – I’d never seen such large robust plants before. I was stoked. Many had seed pods as well.
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January 9, 2012April 6, 2018

Kramer’s twayblade orchid, Liparis krameri

Japan is home to a handful of deciduous Liparis species, commonly called twayblade orchids. One of the more interesting in its leaf form is Liparis krameri, an unassuming herb who’s Japanese name speaks volumes about the flower’s showiness. Simply put, it looks like a small insect! Still, every time I find one of these little plants in the field my heart skips a beat – there it sits on the forest floor like some lost precious jewel.

Liparis krameri plant — Liparis krameri is an unassuming plant, but in my eyes, a little jewel of Japan’s forests.

Liparis krameri is a deciduous woodland terrestrial orchid. A pair of broad glossy leaves ascend from a pseudobulb that sits at ground level. The leaves are markedly veined with the center vein being the most prominent. The leaf edges are flat or undulating, giving the false impression of serrations. They are a bright shiny green, completely hairless, and tapering elegantly to a point; 7-12 cm long and 3-8 cm wide. The pseudobulb is round, but somewhat compressed; 2-3 cm in diameter.

From the center of the leaves the branch less flower stalk grows to a height of 10-25 cm and supports anywhere from 5-20 insect looking flowers. While the flowers are typical looking for a Liparis, they are even more spider-like in appearance than most. Each is about 2 cm long. The broad lip is strongly recurved ending in a point. The long sepals are held in a triangle and are undulating. The hair-like petals are held directly backward The column is long and arching. The flower color is variable from pure bright green throughout to deep purple-brown, and every shade between. Many plants have a complex purple veined lip. The flowers are born sequentially, thus the plant can bloom for weeks.

This twayblade orchid is found throughout the cool temperate regions of Japan as well as the Korean Peninsula, China (Manchuria), and the higher elevations of Taiwan. It lives in moist woodlands in mountain forests. In the mountains of southern Japan it seems to prefer somewhat higher elevations (500+ meters) where night time temperatures are cooler, thus revealing its true nature – a cool temperate climate species.

Liparis krameri flowers — The flowers of Liparis krameri give the plant its Japanese name, jigabachisou, which means “sand digger wasp plant” since the flowers resemble the wasp species Ammophila sabulosa.

This plant is very similar looking to Liparis kumokiri, however, when not in flower L. kumokiri is a larger plant with more broad leaves while L. krameri has more elegantly tapering leaves. The later seems to have more intricately veined leaves as well creating a complex and lovely pattern. While in both species the leaf margins are crimped or frilled, those of L. krameri are to the point of looking serrated from a distance. The flowers, which are born in late spring or early summer, are commonly marked with purple and purple veins, but some have nearly pure green flowers.
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January 8, 2012March 26, 2018

Pinus thunbergii, the Japanese black pine tree

Along the coastal beaches and low mountains of Japan lives a stout and elegant pine species, Pinus thunbergii. This iconic Japanese tree is known for its beauty as a garden specimen, as a bonsai subject, and also a protector of coastline communities throughout the country. It also is well known the world over as Japanese black pine, a versatile and resistant tree, but also a plant with disease issues. It is a lovely tree regardless, and Japan’s gardens and coastlines wouldn’t be the same without its resolute presence.

Pinus thunbergii dunes — Japanese black pine seedlings planted by the thousands are a common sight along Japan’s seashores.

Pinus thunbergii is a large coniferous tree growing to 40 meters under good conditions, but is usually much smaller, particularly when growing on beach dunes, a common habitat for this tree. Specimens found at some Japanese shrines can be even taller with the tallest on record being an incredible 66 meters! This tree often sports a broad dome shaped crown on very old specimens. The bark is silvery to black and deeply fissured. The evergreen needles come two per fascicle (or bundle), are a dark green and up to 12 cm long. Healthy trees are densely needled and bushy looking, especially when young. Pollen cones appear in early spring, are conical and elongate and orange-yellow in color. The seed cones initiate at the same time starting out a rich magenta, and grow in size as they mature over the summer and are nearly round at maturity. Seed is released in winter.

This tree is widespread on or near the coasts of the warmer parts of Japan on Honshu, Shikoku, and Kyushu islands. It is also found in South Korea. It grows most commonly along seashores starting just behind the newest line of dunes and extending inland for a kilometer or more forming the bulk of the canopy of such forests. More inland it prefers rock outcrops and dry ridge-lines in the mountains up to a 1000 meters or more elevation. On occasion it occurs on dry rock barrens in the mountains. Where this species is found in mixed stands with Japanese red pine, Pinus densiflora, the unusual hybrid called akakuromatsu (red-black pine) sometimes results (known under the Latin name, P. x densi-thunbergii). These hybrids have the red bark of P. densiflora while retaining the darker, more stout needles of P. thunbergii.

Pinus thunbergii on dunes — Pinus thunbergii growing on the tops of dunes are typically shaped by the persistent winds.

This is the famous Japanese black pine tree that has been planted throughout much of the temperate world. Historically it was an important lumber species, but these days forests are highly diminished in size, so they are rarely used for building material anymore. It’s wood was traditionally used to build shrines in Korea in particular.
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December 21, 2011April 4, 2018

Lycoris radiata, Japan’s red spider lily

Each fall right at the time of the equinox splashes of brilliant crimson appear along the roadsides and rice patties of southern Japan. These are the flowers of the red spider lily, Lycoris radiata. Like many plants associated with Japan and its people, this flowering bulb is another transplant from China. In Japan it has become culturally significant for religious, cultural, and even practical reasons. Like many members of this small genus, it has an odd genetic history and apparently much of its distribution is the result of human hands.

Lycoris radiata in habitat — Lycoris radiata flowers in sync with the ripening of rice, making a wonderful display. Earthen berms around rice patties are the most common habitat for this species in Japan.

By the 2nd or 3rd week of September, the flower stalks of this plant arise to the height of 30-50 cm and are crowned with a circular cluster of bright red flowers. These are indeed spidery in appearance since all of the flower parts are relatively thin and long. The sepals and petals are essentially identical in shape in size and recurve backward. Their margins are either flat or slightly undulating and are 4-6 cm long and about 1 cm wide. The pistol and stamens are long, curving upward in graceful arcs, each between 6-8 cm long. As the flowers age the red color fades a bit and pink striations form giving them a peppermint striped appearance.

The flowers fade within a week or so, and almost immediately new leaves emerge from the subterranean bulbs. The leaves look much like a daffodil’s and are a dark green color with a hint of blue. They take some time to form but eventually can reach up to 30 cm or more and are 1-2 cm wide. These persist all winter long, fading sometime in late spring. As mentioned, these plants grow from bulbs that are typical looking with a scaly outside covering and are anywhere from 5-8 cm long and 3-5 cm wide. They readily form offsets, so plants left alone quickly form large clumps. Virtually all plants found in nature exist as clumps rather than as single individuals.

Lycoris radiata leaves — The leaves of Lycoris radiata look much like a common daffodil, but they grow in the fall just after flowering and persist all winter.

This common plant is found in the warmer regions of Japan, but in fact is a transplant from China. It is also found in Korea where it is equally exotic. Habitats range from fields, roadsides, river banks, to bright wooded groves, but it is most commonly found on the berms of rice patties in full sun. It has naturalized in some parts of the southeastern USA, but I suspect these plants were put there by people years ago and persisted after their owners left.

What a strange plant this is in nearly all respects. One common English name for Lycoris is “surprise lily” since they come out of the ground in mid to late summer with gaudy clusters of flowers perched on top of leafless stalks (for the same reason they have earned the name “naked lady”). The leaves follow the flowers after they fade and last all winter long only to go dormant in late spring. What is more curious is that virtually all Japanese and Korean plants are sterile triploid plants that can only be reproduced through vegetative propagation and presumably were distributed over a wide geographic region by humans exclusively.

Here is a video of L. radiata and L. albiflora in habitat along the Inunaki River near Fukuoka City, Kyushu, Japan:

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December 13, 2011April 6, 2018

Naturally Occurring Cypripediums in Cultivation – Part II

As you can surmise from these entries, many Cypripediums have yet to be artificially produced in large numbers, especially by means of micropropagation techniques. Of the 59 species, recognized varieties, and naturally occurring hybrids listed here, only 14 of these have been propagated in any quantity over the last two decades.

Moreover, 11 of these are either from the subsection Cypripedium or are hybrids of that subsection, and out of those, three are varieties of one species, C. parviflorum. Clearly, this group is the easiest to cultivate with known propagation techniques. Indeed, only 3 species outside this subsection have been mass propagated to adult size, C. californicum, C. guttatum, and C. reginae. In truth, of these only C. reginae has been truly mass produced to date. Regardless, lady slipper orchids remain some of the most sought after of all terrestrial orchids to this day – hence, there is a big disconnect between demand for them and the supply.

The most widespread of all the North American Cyps is Cypripedium parviflorum v. pubescens. It is one of the easiest species to grow. Grown and photographed by Paul Perakos.

So, this begs the following questions, why is this the current situation and where are plants in cultivation coming from? The second question is easy to answer – many if not most are coming from the wild. The first question is more difficult. The bottom line is that most species are either tricky to germinate and/or they do not grow well afterwards. Others are simply slow growing, taking many years to bloom. Still others have high mortality rates from seed to adult size.

The simple truth is that before 1990 only a handful of expert growers such as Carson Whitlow and Werner Frosch were even attempting Cypripedium micropropagation. In the mid 90s that began to change with quite a few growers world wide getting in on the game. Dr. Bill Steele helped wax the wheel by making his nutrient formulations free and public to all. By late in the decade many thousands of Cyps, both naturally occurring and artificial hybrids, had been produced and sold. Recently, the focus of many propagators has been on artificial hybrids since they offer more variety and most are much easier to grow than the species. The upshot is, there is still a lot of work to do in effectively growing most of the known Cypripedium species.

For these reasons and others, Cyps remain a niche market in the horticultural trade. This situation also brings the inevitable – high prices for even the easiest and most commonly produced plants. All of this goes beyond the scope of this article though, so perhaps this discussion should handled at another time.

Here are the remaining plants. The names highlighted in blue are clickable links to more comprehensive pages about that plant:

japonicum – a widely kept species that remains difficult to grow and apparently very difficult to flower even after being firmly established. It is found throughout much of central China, the Korean Peninsula, and virtually all of Japan. As such it is fairly indifferent to temperatures enduring both severe and mild winters, and cool to very warm summers. It needs a lot of room to range since the distance between growths can be 15 centimeters or more. It is completely intolerant of dry conditions and is also a heavy feeder. Best grown in the ground in acidic conditions in a decidedly organic compost. Production from seed has been very difficult, so plants in the trade are virtually all wild sourced. When happy it forms formidable colonies with thousands of flowering stems. Not an easy species. USDA zones 4-9.

Cypripedium lichiangense is perhaps one of the most spectacular of the spotted leaf Cyps. Grown and photographed by Rogier van Vugt.

December 8, 2011April 6, 2018

Naturally Occurring Cypripediums in Cultivation – Part I

The following is a list of all known generally accepted naturally occurring lady slipper orchids, genus Cypripedium, and their cultivation status. No doubt in the coming years more hybrids will come to light, especially from China’s vast western mountains. Each year new plants are being found there that suggest hybrid origin, but as yet remain undescribed by science. There indeed is even a chance that a few unknown species yet reside there, tucked away in some inaccessible niche. The focus here is on Cypripedium availability on the world market, how challenging their cultivation has proved, what their specific needs are, and where plants have been sourced to date.

Since information is constantly changing and many growers are tight lipped about their doings, the following cannot be inclusive of all plants in cultivation. What is offered is a product of my own discussions with growers, scientists, “stuff off the grape vine”, and my own personal experience. I have avoided addressing the legality of any particular species, but suffice it to say that many plants have made it into the trade via illegal smuggling. This leaves a big question mark on the status of plants in countries that are signees of CITES since all are covered under this treaty.

Cypripedium acuale — Cypripedium acaule – one of the most unique and difficult to grow ladyslippers.

The USDA zone recommendations given are not to be taken as a strict guideline. In cooler summer climates such as the Pacific Northwest of the USA or most of the British Isles, many species can be grown even in what qualifies as zone 9. Like other temperate terrestrial orchids, Cypripediums as a rule do not like hot roots, so areas with hot summer nights are unlikely to be good places to grow any of them, but a few might persist if grown optimally.

So, without further adieu, here is the first half of the list. The names highlighted in blue are clickable links to more comprehensive pages about that plant.

acaule – this species is widely cultivated from both wild and artificially produced plants. This plant cannot grow in typical garden soil, requiring very high acidity (pH <4.5). Sandy, open, pine humus rich composts have been effective, but still have to be watched very carefully for increases in pH. The best method devised so far is watering regularly with a solution of acidified rainwater (household vinegar is fine – 1 or 2 teaspoons per gallon). Use only clean rainwater, RO water, or distilled water since the plants cannot endure salt build-up in the growing medium. Avoid planting in the ground in regions with sweet soils since keeping pH down is nearly impossible. If fertilizer is used, use a very dilute solution or add nutrients via natural matter such as composed pine needles. A very difficult plant to maintain in the long term even within its native range, but possible. USDA zones 2-7.

x alaskanum – the natural hybrid of C. guttatum and C. yatabeanum from the Aleutian Islands of Alaska. Grow as per C. guttatum. Occasionally offered. USDA zones 2-5.

Cypripedium x andrewsii – an easy to grow natural hybrid between C. candidum and C. parviflorum v. parviflorum. Grown and photographed by Paul Perakos.

x andrewsii – the natural hybrid between C. candidum and C. parviflorum v. parviflorum. Seems to enjoy quite a bit of sun, at least in the morning, and any near neutral soil will do nicely. Widely cultivated from lab propagated plants. Easy. USDA zones 3-7.

arietinum – widely cultivated, but difficult and rare. Sandy compost with conifer humus will do provided it remains open and free draining. Acidity should be between pH 5 to 7. It is susceptible to rots, so avoid saturated conditions. While it is very cold tolerant, it is also incapable of enduring long periods of summer heat. Plants tend to reach flowering age much quicker than most species or hybrids. USDA zones 2-5.
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November 16, 2011March 23, 2018

Cycas revoluta v. aurea, an odd type of king sago

In the islands around Amami Oshima, just north of Okinawa, Japan, there exists an odd type of Cycas revoluta known in the west as variety aurea. This is not your typical king sago, nor is it the result of poor growing conditions, bizarre horticultural techniques, or a virus. It rather is a consequence of a genetic anomaly, as we’ll see in the following picture sequence.

Cycas revoluta v. aurea is a naturally occurring form that boasts an interesting color pattern on its otherwise normal fronds – each pinna is tipped in gold. These yellow tips are attractive to some while others think it makes the plant look diseased or ill treated. To my eye, the regular pattern of yellow against the dark green of the inner pinnae is indeed attractive, particularly at a distance. In Japan it goes by the names kogane sotetsu (gold cycad) and kinbuchi sotetsu (gold rim cycad). The following is the growth cycle of a plant over the past year here in southern Japan.

In June the plant begins its flush and by early July the new fronds have matured and hardened, but remain a bright green color. If you look closely, you can see that already the very tips of the pinnae are turning yellow.

By early August the yellowing process is in full swing and the inner segments of the pinnae are now fully mature and taking on the characteristic deep green of this species.

A couple weeks later the yellow has deepened further and the plant is at its best, with little or no browning of the tips yet.

Cycas revoluta v. aurea 8/17 — 8/17/2011