Showing posts with label Experiments in cold hardiness. Show all posts
Showing posts with label Experiments in cold hardiness. Show all posts

Thursday, February 21, 2013

Peyote purple from extreme cold

Purple peyote seedlings - a sign of extreme conditions
Purple peyote seedlings - a sign of extreme conditions

A purple colored epidermis is a common stress indicator for a number of cacti - stress caused either by cold or draught - and consequently can be seen as a sign of extreme growing conditions.

The peyote seedlings in the above photo haven’t seen a drop of water since late August/early September, i.e. they have been without water for almost half a year. And the last time I checked, the temperature in the coldhouse where the seedlings grow had been as low as -10C (14F). Extreme conditions for peyote seedlings indeed! And the explanation for their purple hue.

The plants are grown from seed originating from El Oso, Coahuila, Mexico. Given the locality and the seedlings’ ability to endure extreme cold and dry conditions I expect them to be Lophophora williamsii var. echinata.

Speaking of purple Lophophora williamsii var. echinata the below photo was posted a while ago by Keeper Trout. The picture shows a patch of mature peyote turned purple by the cold. According to Trout, the area in Texas where the plants grow had experienced a "hundred year freeze" including three days where the highest temperature measured at a nearby locality was 10F (less than -12C).

Purple peyote in habitat in Texas
Purple peyote in habitat in Texas

The frost in western Texas killed off a lot of things considered freeze-hardy - including the dead peyote pictured below. This plant was from a different population than the purple patch pictured above and might have seen slightly colder temperatures, but still it’s a good indication that the freezing temperatures these plants experienced are at the limit of what Lophophora williamsii var. echinata will stand.

Dead peyote in habitat in Texas
Dead peyote in habitat in Texas

As mentioned at the beginning of this post a purple tinted epidermis is a common sign of stress in many cacti. Another example from my coldhouse is the purplish-hued Ariocarpus retusus pictured below.

Ariocarpus retusus (SB 310; Cuesta la Muralla, Coahuila)
Purple tinted Ariocarpus retusus (SB 310; Cuesta la Muralla, Coahuila)


The mature peyote photos are courtesy of Keeper Trout and the Cactus Conservation Institute and originate from this post on The Corroboree.

Tuesday, February 12, 2013

Peyote, Ariocarpus and Normanbokea in the depth of winter

Winter dormant peyote cactus
Winter dormant peyote cactus

Following a relatively mild period the last couple of years have seen freezing cold winters here in Denmark - winters that have been tough to my coldhouse grown plants, and especially the deep frost of 2009/2010 killed off a significant number of my coldhouse collection. But it also separated the wheat from the chaff leaving a pretty cold-hardy assemblage of plants, the dormant Lophophora williamsii var. echinata (JJH 8608293; Pecos River area) pictured above being a majestic example.

Ariocarpus kotschoubeyanus var. macdowellii (SB 100; El Pilar, Coahuila)
Ariocarpus kotschoubeyanus var. macdowellii (SB 100; El Pilar, Coahuila)

Most of the cacti growing in the coldhouse are selected for their (sometimes assumed) ability to survive freezing conditions. For example I prefer the Trans-Pecos variety of peyote as it is more frost hardy than the tender regular variety - and the different Ariocarpi all originate from the northernmost part of the species’ respective ranges.

Ariocarpus fissuratus (SB 403; Crockett Co, Texas)
Ariocarpus fissuratus (SB 403; Crockett Co, Texas)

Even though the cacti already have survived several cold winters I can’t deny that I still worry what plants will die off during winter (as some inevitably will).

The pictures appearing in this post were taken between Christmas and New Year - at that time the plants had already been exposed to temperatures in the vicinity of -10 C (approximately 14 F). Since then they have seen both mild and humid weather and long periods of frost - I expect that these fluctuations in temperature are harder to cope with for the plants than uniform periods of cold, but it’s just a hunch. Anyway I’m eagerly looking forward to spring :-)

Ariocarpus retusus (SB 310; Cuesta la Muralla, Coahuila)
Ariocarpus retusus (SB 310; Cuesta la Muralla, Coahuila)

But it is not just the cold that poses a threat to my plants. Previously critters have eaten large bites out of some of my peyote plants and now several of my Normanbokea valdeziana plants have met the same destiny... I still haven’t figured out what culprit is eating my cacti (or at least tasting and spitting out again)!

Normanbokea valdeziana (SB 1468; Ramos Arizpe, Coahuila, Mexico) eaten into by some unknown critter
Normanbokea valdeziana (SB 1468; Ramos Arizpe, Coahuila, Mexico) eaten into by some unknown critter

Sunday, April 11, 2010

The killing frost – casualties and survivors

First a bit of background information so that you guys won’t believe that I am completely stupid growing Lophophora and the likes in an unheated greenhouse in Denmark: 1) Most of these plants are “surplus”, i.e. I don’t have room for them anywhere else – lately several plants have been bought specifically for the cold house, though. 2) The greenhouse is located at my summerhouse, left mostly desolate throughout winter, making it difficult to keep it reliably heated. 3) Many cactus species tolerate more frost than is generally assumed; I’m curious which. 4) The winters in Denmark have been rather mild lately, inviting experiments like this.

With this in place I’m ready to recount how the harsh winter, that has just released its cold grip of Denmark, helped me separate the wheat from the chaff (a blatant euphemism for “killing off alarmingly large parts of my collection”). Just to give an understanding of the severity of the winter, the plants saw almost constant frost for more than 10 weeks, with temperatures measured as low as -15 C (5 F) in the area where the plants grow.

Lophophora williamsii var. echinata coming out of winter
Lophophora williamsii var. echinata coming out of winter

Let’s start with one of the success stories. My Trans-Pecos peyote plants are doing quite well, approximately one in eight died and the surviving plants are not too marked by the frost. The plants I'm growing are descending from material originally collected in the Pecos River area, Val Verde County, Texas (JJH 8608293). The Trans-Pecos peyote is the northernmost form of Lophophora williamsii and is also known as Lophophora williamsii var. echinata.

Trans-Pecos peyote surviving the frost
Trans-Pecos peyote surviving the frost

My regular (Mexican and south Texan) Lophophora williamsii plants fared much worse, less than one in ten of the larger plants survived the winter.

One of the few surviving Lophophora williamsii var. williamsii
One of the few surviving Lophophora williamsii var. williamsii

This corresponds well with Del Weniger’s observations:

[Lophophora williamsii var. echinata] can also survive the much more severe cold of the Big Bend. I have several times had the smaller form from south Texas [L. williamsii var. williamsii] freeze in San Antonio, while this form [L. williamsii var. echinata] growing in the same bed showed no ill effects.

In the future I'll focus more on the extreme northern forms of peyote, i.e. plants grown from material originating from Shafter, Val Verde, Big Bend and other Trans-Pecos, Texas locations. The Cactus Conservation Institute has an informative page on the differences in traits between Lophophora williamsii var. echinata and var. williamsii.

Frost killed Lophophora williamsii, Starr County, Texas
Frost killed Lophophora williamsii, Starr County, Texas

As mentioned the majority of my large “regular” Lophophora williamsii were killed by the frost. But many medium sized seedling plants actually survived while the larger plants (of the same variety) and yearling seedlings succumbed. As this pattern seems to be rather consistent for plants of the same variety, I guess I can’t write all “regular” Lophophora williamsii casualties off to genetics. My theory is that this “size-conditioned” difference in survival must be related to how well the plants were prepared for the winter, which again may be closely related to the surface-area-to-volume ratio of the plant.

The surface-area-to-volume ratio (SA:V) decreases with size, i.e. a large plant will have less surface per unit of volume than a smaller plant. If we use a half sphere as a model for a globular cactus we get a SA:V of 3/r, where r is the radius. Consequently a large plant will need relatively longer time (per unit of volume) to go flaccid and prepare properly for the winter (as all excess water needs to be evaporated through the surface (the epidermis)). Similarly seedlings are more prone to die of drought as an increased SA:V means increased exposure to the environment in general.

To play it safe the coming growing seasons I'll stop watering my large plants well before I let seedlings go drought dormant in preparation for the winter, and in general start winter preparations earlier than I have used to in the past.

I might consider crossing the surviving mature (non Trans-Pecos) plants and name the cultivar Lophophora williamsii 'Borealis' ;-)

Frost killed Leuchtenbergia principis – outside the rain is weeping
Frost killed Leuchtenbergia principis – outside the rain is weeping

My largest Leuchtenbergia principis is dead (pictured above next to a surviving saguaro) while 3 out of 4 of my smaller Leuchtenbergia principis plants (GL 770; Sierra de la Paila) are looking happy.

Ariocarpus has turned out to be an unconditional coldhouse success. I expected my Ariocarpus fissuratus plants to make it safely through the winter as they originate from locations like Fort Stockton, Texas (JM 122) and Crockett County, Texas (SB 403), but I had doubts about my Ariocarpus kotschoubeyanus var. macdowellii plants (SB 100; El Pilar, Coahuila), and had accepted that I would probably loose my Ariocarpus retusus (SB 310; Cuesta la Muralla, Coahuila). Amazingly they all survived the winter in great style almost looking lush and vigorous, like a winter swimmer surfacing with renewed energy after a cold plunge.

Surviving Ariocarpus, Epithelantha, and Leuchtenbergia plants
Surviving Ariocarpus, Epithelantha, and Leuchtenbergia plants

Epithelantha is another seriously cold tolerant genus. My Epithelantha micromeris var. greggii plants (Cuesta la Muralla, Coahuila, Mexico) all made it; one is seriously damaged, though – it looks like the root is dead while the crown looks fine, so I hope to be able to re-root it. The Epithelantha bokei plants (SB 416; Brewster Co, Texas) also look fine, but due to the extremely dense spination it is hard to say for sure if they are completely undamaged. Strangely the cold has taken the hardest toll on my regular Epithelantha micromeris (SB1327; near Belen, New Mexico) – this variety of E. micromeris is from the northernmost known locality of the species so I had expected the plants to cope better with the frost.

Surviving Obregonia denegrii plants
Surviving Obregonia denegrii plants

Last summer I moved a handful of Obregonia denegrii seedlings (VVZ 163; San Vicente, Tamaulipas) to the coldhouse. I really didn’t expect these plants to be cold hardy, but didn’t have room for them anywhere else. Surprisingly approximately two thirds of the plants survived as illustrated in the above picture (the surrounding pots are not empty, each contain a rather large L. williamsii killed by the cold).

Other success stories are Normanbokea valdeziana, Homalocephala texensis, and Mammillaria meiacantha which all made it through the winter without casualties – the Normanbokea plants are even budding. Acharagma roseana is another species that’s shaking off the winter blues and getting ready to bloom – in general Acharagma seems to handle the cold pretty well, even most of my yearling Acharagma aguirreana seedlings survived. Most Escobaria and Echinocereus obviously had minimal problems with the frost.

Frost killed Lophophora williamsii turning to mush
Frost killed Lophophora williamsii turning to mush

As mentioned above the majority of my larger, regular Lophophora williamsii plants were killed by the frost, but the more tender Lophophora species like Lophophora diffusa and L. fricii are completely eradicated – I’ll probably not experiment further with these species in the coldhouse, the exception maybe being montane varieties of Lophophora fricii.

Dead Lophophora diffusa
Dead Lophophora diffusa

Other species that are completely wiped out include Matucana madisoniorum, an unknown Echinopsis hybrid, Ferocactus glucescens (PP 1354), Lithops lesliei (not exactly a cactus, I know ;-), and Harrisia jusbertii. Surprisingly all my Mammillaria grahamii also died – I had expected this species to be more cold hardy.

Most of my saguaro cactus (Carnegiea gigantea) also succumbed to the frost – 4 plants look like they might survive, most of them badly damaged, but it is too early to say.

I need to start building a new collection of grafting stock – all Trichocereus plants that I grew in the coldhouse are dead, including Trichocereus pachanoi, T. peruvianus, Trichocereus 'Tom Juul’s Giant', and a Penis Cactus… they are all gone. Even plants that were well prepared for the winter died, so Trichocereus is definitely not as tolerant to frost as I had expected.

Decomposing Trichocereus plants
Decomposing Trichocereus plants

To put the death toll into perspective this is the coldest winter in 14 years in Denmark (followed by March, a month with the most extreme temperature fluctuations in 14 years, which were not very becoming to my struggling plants either). The frost set in just before Christmas and only lifted again in the beginning of March. The lowest temperatures measured in the area were as low as -15 C (5 F).

Outdoor temperature in late January
Outdoor temperature in late January

Once in a while short bursts of thaw set in quickly followed by frost (as indicated by the above graph), making the conditions even harder for the plants.

Outdoor temperature in mid February
Outdoor temperature in mid February

The temperature measurements come from a semi-professional weather station located approximately 1.5 km (~ one mile) from where I grow my plants, so these temperatures are representative for those that my plants where exposed to.

To end on a positive note I expect the frost to have killed off many pests also (including red spider mites). Also, I got an affirmative confirmation that it is actually possible for peyote to survive rather extreme conditions in an unheated greenhouse in Denmark... and I got plenty of room for new plants ;-)

Tuesday, December 29, 2009

The killing frost

The fact that the last many winters have been mild in Denmark has made me act with presumption, ignoring several basic rules for growing cacti in freezing conditions. The week before Christmas Denmark was hit by an early cold spell, bringing hard frost that made many of my coldhouse grown plants suffer the consequences of my folly.

Frozen Lophophora williamsii (SB 854; Starr Co, Texas)
Frozen Lophophora williamsii (SB 854; Starr Co, Texas)

The family spent the Christmas holidays in the summerhouse arriving late December 21, the day of the winter solstice. Of course I had to check up on my plants in the coldhouse first thing, but was met by a disheartening sight: The beautiful turgid, dark jade green Lophophora williamsii plants pictured above are frozen solid.

Lophophora williamsii draped in horticultural fleece
Lophophora williamsii draped in horticultural fleece

The greenhouse walls are covered with curtains and the plants are draped in horticultural fleece to protect them from the cold, still the temperature was measured to slightly less than -7 C (~ 19 F) just next to the plants. The temperature alone shouldn't be a problem as these plants have endured conditions in the coldhouse since 2004 (actually these very plants started my experiments in Lophophora cold hardiness so I'm double sad to loose them), but freezing conditions combined with plants that haven't had the time to go flaccid before subjected to the frost is a deadly cocktail. I'm sad to admit that I watered the above Lophophora williamsii plants along with a couple of Gymnocalyciums and two large pots of 3 year old L. williamsii seedlings very late in the season (late September). To make things worse October and November came with a perpetual overcast sky and constant, high humidity levels, leaving the plants no chance to dry out thoroughly. Finally, to top things off, December brought very early and double digit freezing temperatures (measured in celsius) killing off the plants still bloated with water. I have learned my lesson and will never water any of my coldhouse plants later than the end of August (the exception being very young seedlings that might otherwise succumb to drought).

Thawed Lophophora williamsii (SB 854; Starr Co, Texas)
Thawed Lophophora williamsii (SB 854; Starr Co, Texas)

Come Boxing Day the frost went away, leaving me with thawing plants and the possibility to asses the damage – unfortunately I had to leave for home the day after, so the exact casualty figures will follow in a later post.

The thawed Lophophora williamsii plants pictured above felt soft and slightly mushy to the touch but I didn't have the heart to squish them to see if they were fluid inside.

Thawed Lophophora williamsii seedlings
Thawed Lophophora williamsii seedlings

The two large pots of 3 year old Lophophora williamsii seedlings are gone for sure. Upon thawing the seedlings first felt like small bags of slush ice before the interior turned completely fluid. Subjected to a light pressure the epidermis broke and liquid oozed out, indicating that the cell walls are lacerated by the frost.

Frost killed Lophophora diffusa
Frost killed Lophophora diffusa

Another mistake I made was to move new plants into the coldhouse without leaving them sufficient time to acclimatize properly for the winter – the plants were moved to the coldhouse in late September/early October. On that account I lost 3 large Lophophora diffusa like the one pictured above.

As is evident from the flaccid (and very much alive) L. diffusa pictured below, these plants are able to survive the cold conditions if treated properly. The two plants are from the same batch, are growing under the same conditions (and the pictures were taken the same day). The only difference being that the survivor was given proper time to adjust to its harsh environment.

Alive Lophophora diffusa
Alive Lophophora diffusa

I also recently introduced a handful of new Ariocarpus plants to the coldhouse – they had me somewhat worried but seem to cope.

Frost damaged Penis Cactus
Frost damaged Penis Cactus

My last mistake was to leave a collection of columnar cacti out on the terrace until mid October, exposing them to precipitation and moisture for much longer than what's healthy for plants that must winter in freezing conditions. This has taken its toll on my formerly so erect Penis Cactus - I'm not sure if the plant is completely killed off by the frost but it is certainly damaged. I'm worried for the rest of my Trichocereus collection also; many of the plants felt completely frozen to the touch but are not showing any evident signs of damage yet – time will tell, though.


The lesson I have learned from this experience is to always expect the worst from the weather and prepare accordingly (which should have been evident in the first place!). Even if the last many winters have been mild, I should have known that frost can set in suddenly and quite early in Denmark – instead of being lulled into the assumption that most of the winter would be mild with hard frost arriving late, as the situation has been the last few years. I won't be that careless in the future.

After a couple of mild days the weather reports again predict a period of hard, day- and nighttime, frost extending into the new year.

Update, April 11, 2010
Read more about the casualties and survivors of the frost.

Thursday, April 23, 2009

Spring awakening in the coldhouse

All of the photos in this post were taken at the beginning of April to illustrate some of the spring activity in my coldhouse. The plants have been kept dormant all through winter and received their first drink of water only a few days before these pictures were shot.

Flowering Lophophora williamsii (El Huizache, San Luis Potosí)
Flowering Lophophora williamsii (El Huizache, San Luis Potosí)

The first plant I want to show off is a flowering Lophophora williamsii grown from seed originating from the El Huizache, San Luis Potosí, Mexico population (the population Anderson assigned as the neotype for the species). These plants are from a more southerly location than the ones I'm usually growing and I'm happy to see they are coping so well with the cold conditions during winter. I was getting used to thinking of all L. williamsii varieties as self-fertile but according to the Cactus Conservation Institute, greenhouse breeding experiments by Bohata and colleagues in the Czech Republic and by Köhres in Germany have shown that plants from the El Huizache population are self-sterile and therefore obligate outcrossers (leading one to suspect a great deal of genetic diversity within plants from this population – in contrast to the self-fertile populations that have little to no genetic diversity among individuals as they outcross very little).

Lophophora williamsii (El Huizache) flower with long style
Lophophora williamsii (El Huizache) flower with long style

The flowers of the El Huizache plants also seem to have a very long style that raises the stigma well above the stamens, making it hard, if not impossible, for the plants to reproduce without the help of a pollinator.

Bumble bee having fun with a Lophophora williamsii flower
Bumble bee having fun with a Lophophora williamsii flower

Speaking of pollinators a bumble bee visited while I took these pictures – unfortunately only this one Lophophora flowered at the time making it impossible for the bee to fertilize the plant. The bumble bees that are active in early spring are huge; I don't know much about bees but am told that these large slow individuals are queen bees looking for nectar and pollen to feed their newly hatched brood.

Lophophora williamsii (SB 854; Starr Co, Texas) with fresh fruit
Lophophora williamsii (SB 854; Starr Co, Texas) with fresh fruit

One of the Lophophora williamsii (SB 854; Starr Co, Texas) plants that I recently repotted has spawned a fruit. This variety of Lophophora williamsii is self-fertile to an extent where it happily sets seed if you just shake the flower a bit.

Flowering  Acharagma roseana (LX 578; Ramon Arizpe, Coahuila)
Flowering Acharagma roseana (LX 578; Ramon Arizpe, Coahuila)

My Acharagma roseana plants (LX 578; Ramon Arizpe, Coahuila - “Ramon” should probably read “Ramos” but I'll stick to the information from the vendors seed list) are coming of age. The plants were started from seed 4 years ago and are all ready to flower, displaying a wealth of flower buds. Only one, shown in the picture above, flowered when I took the pictures. Unfortunately it will be a while before I can visit my summerhouse (and coldhouse) again – I hope at least a few of the flowers will be saved for then. My Echinocereus reichenbachii plants are also growing a multitude of buds, getting ready for a flower fest I would hate to miss.

Frost damaged Matucana madisoniorum
Frost damaged Matucana madisoniorum

Until now I have focused entirely on the success stories but a few of my plants didn't like being without heat during winter. My Matucana madisoniorum definitely didn't like the cold conditions (even being wrapped in multiple layers of horticultural fleece). The plant is heavily marked by the experience but survives.

I also lost a few plants: a couple of Carnegia gigantea (saguaro cactus), a Cylindropuntia bigelovii (teddy-bear cholla), and a Cylindropuntia tunicata (thistle cholla); I managed to save cuttings of the chollas though. These plants were kept out on the terrace all summer and I probably left them out for too long, exposing them to the autumn storms so the plants were not able to dry out completely before winter. I'm especially sad about the Carnegia gigantea plants as they were great specimens and are now completely reduced to mush.

Sunday, March 15, 2009

Repotting Lophophora williamsii in the coldhouse

Since 2004 I have experimented with growing Lophophora williamsii in an unheated greenhouse in Denmark. During this period the plants have been repotted only once a couple of years ago.

Coldhouse grown Lophophora williamsii (SB 854; Starr Co, Texas)
Coldhouse grown Lophophora williamsii (SB 854; Starr Co, Texas)

The plants are growing in 11 cm (4.33'') clay pots and it might not be apparent from a superficial inspection that they are in need of being repotted again. But on closer investigation it turns out that the taproots are visible through the drainage hole in the bottom of the pots.

Taproot visible through drainage hole
Taproot visible through drainage hole

I consequently decided to repot the plants. I'm usually not repotting plants in the coldhouse this early in the year as we still might get the occasional night with sub-freezing temperatures, but I figured that the plants are completely dormant – i.e. there are no actively growing roots to harm – and if repotted in bone-dry soil the plants will not notice they have been disturbed when the growing season starts in a few weeks. Anyway, that's my theory ;-)

Lophophora williamsii plants removed from the pots
Lophophora williamsii plants removed from the pots

Close-up of three Lophophora williamsii crowns
Close-up of three Lophophora williamsii crowns

Close-up of exposed Lophophora williamsii taproot-ball
Close-up of exposed Lophophora williamsii taproot-ball

After removing the plants from their pots I could smell that some of the roots had been damaged; a broken Lophophora root gives off an easily detectable smell reminiscent (to me anyway ;-) of that of fresh green peas. This stressed the fact that the soil really had to be bone-dry before potting the plants, so I let them sit for a day in order for the broken roots to dry out a bit, and shoved the soil into the oven to remove every last bit of moisture it might hold (this gave off an... let's call it interesting... smell and I weren't popular at all with the rest of the house).

The soil ended up being so dry that I was literally working in a cloud of dust while repotting – my throat was still irritated the day after so I'll probably buy a dust mask to avoid this situation in the future (not that I expect to get pneumoconiosis or anything but it's annoying to go “ahem”, “hrmph”, “cough” for a day when it can be avoided ;-).

Freshly repotted Lophophora williamsii plants
Freshly repotted Lophophora williamsii plants

The dry and dusty soil is also evident by the dusted fingerprints on the pots (12 x 12 x 20 cm, ideal for plants with large taproots) in the picture above.

Lastly I would like to make a note on the soil. I am adding unperfumed (and unused ;-) cat litter made from baked “moler” to my soil as this material is very lightweight and retains water easily without the soil getting soaked. I'm not quite sure how to translate “moler” into English but it is a diatomite deposit that Skamol, a “moler” processing plant, defines as:

Moler - a diatomaceous earth
Diatomaceous earth is a naturally occurring, soft, chalk-like sedimentary rock that is easily crumbled into a fine white to off-white powder. This powder has an abrasive feel, similar to pumice powder, and is very light, due to its high porosity. Moler is a special mixture of diatomaceous earth and bentonite clay, ca. 60% diatoms and 40% clay. The clay gives the raw moler a brownish colour, and due to a high iron oxide content the materials become pink, when baked.

The pinkish granules visible in the topsoil in the photo above is “moler” cat litter.

As I live within driving distance of where the “moler” is quarried I decided to get some raw and unbaked “moler” to mix into my soil. Last summer I collected a few bags in the, now defunct, quarry pictured below; the plants described in this post are the first to be planted in soil with chunks of raw “moler” mixed in (visible as large, grayish flakes in the above picture), so I'm eager to see how the plants agree with this new additive to their soil. Even though “moler” contains large fractions of clay (the Danish word “ler” means clay, i.e. a literal translation of “moler” would be mo-clay) it's a relatively stable material that doesn't dissolve in water, so it will not clog up the soil when watered.

Old moler quarry on the island of Mors
Old moler quarry on the island of Mors

I'm a bit curious as to what effect diatomaceous earth has on insects. According to Wikipedia “diatomite is also used as an insecticide, due to its physico-sorptive properties. The fine powder absorbs lipids from the waxy outer layer of insects' exoskeletons, causing them to dehydrate”, i.e. the diatomaceous earth in the “moler” might actively help me control pests.

Monday, February 02, 2009

Flowering Lophophora decipiens

Flowering Lophophora decipiens
Flowering Lophophora decipiens

In 2005 I sowed my first Lophophora decipiens seeds bought from Pavel Pavlicek. The plants grow in my coldhouse and flowered for the first time in the summer of 2008 where these pictures were taken.

Flowering Lophophora decipiens viewed from above
Flowering Lophophora decipiens viewed from above

I'm not quite sure what to make of the long, flimsy, pink petals, and the plants are still too young to tell what the adult body morphology will look like so for now I can only say that the plants live up to their name (decipiens meaning “deceiving” ;-)

Leon Croizat's description of Lophophora williamsii var. decipiens stated that the vegetative body of this variety was basally tubercled or with distinct podaria rather than ribs, and that the flower extended out of the top of the plant to a greater extent. This description was based entirely on an illustration in Britton and Rose, The Cactaceae volume 3, plate 10, figure 4 (see below). Some researchers, e.g. Anderson, have argued that these characters are not consistent enough in occurrence to justify separate taxonomic status while others, including Gerhard Köhres, state that plants corresponding to Croizat's description grow near El Amparo in the state of Coahuila, Mexico and should be counted to the Lophophora fricii complex.

Britton and Rose, The Cactaceae, Volume III, Plate X
The Cactaceae, Volume III, Plate X

I have recently bought some Lophophora decipiens seeds from Steve Brack and look forward to see how they develops.

Tuesday, September 30, 2008

Fruiting Epithelantha micromeris, take two

A few weeks ago I posted on my fruit bearing Epithelantha micromeris (SB1327; near Belen, New Mexico) plants. The color of the fresh fruit is a bright pinkish red that changes to a deep, warm, saturated blood red color as the fruit dries.

Epithelantha micromeris with dry fruits
Epithelantha micromeris with dry fruits

In close-up the Epithelantha micromeris fruits are strangely reminiscent of small (weirdly colored ;-) cacao pods.

Close-up of dry Epithelantha micromeris fruits
Close-up of dry Epithelantha micromeris fruits

When the last rays of the setting autumn sun shine on the fruits they assume an out of this world, glowing warm red color. I tried to capture it in the photo below but it doesn't quite do justice to the shimmering, radiant quality of the color (as should be evident by now I'm a sucker for the amazing palette of red nuances displayed by these little fruits ;-)

Fruits lit by the setting sun
Fruits lit by the setting sun

Monday, August 11, 2008

Coldhouse grown Lophophora williamsii - the next generation

Four years ago I started my first batch of coldhouse grown Lophophora williamsii (SB 854; Starr Co, Texas) from seed. I've lost a few plants to frost during the years but the survivors have coped surprisingly well, enduring the Danish winters in an unheated greenhouse without problems (that being said, I still worry a bit for the plants every winter ;-).

Flowering Lophophora williamsii (SB 854; Starr Co, Texas)
Flowering Lophophora williamsii (SB 854; Starr Co, Texas)

The plants are now old enough to flower and have been doing so freely all summer. The above photo was taken late June and today the plants are still flowering.

I have pollinated as many flowers as possible - if more plants flower at the same time the flowers are cross-pollinated, otherwise selfed. A cotton-tipped swab can be used for transferring the pollen from the anther and deposit it on the stigma.

Lophophora williamsii pollinated with the help of a Q-tip
Lophophora williamsii pollinated with the help of a Q-tip

Lophophora williamsii with pollen deposited on the stigma
Lophophora williamsii with pollen deposited on the stigma

The plants have already set the first fruits (the picture below was taken at the end of July) - I can't say if these fruits are the result of the flowers being pollinated 5 weeks before, but I'm currently conducting some experiments to get a better understanding of how much time passes between a flower is pollinated and the resulting fruit appears.

Fruiting Lophophora williamsii
Fruiting Lophophora williamsii

As mentioned above I cross-pollinate my Lophophora williamsii plants when possible (I don't cross plants from different locations though). This might be a waste of time as preliminary studies by Martin Terry indicate that outcrossing is close to zero (i.e. selfing is virtually 100%) in natural populations and all individuals in a given population are clones. The study is based on data from three Texan populations, including Starr County, and the results are not definite - but if the results are correct it would also mean that my surviving (Starr County) plants are not more fit for the coldhouse, genetically speaking, than the ones that died off as they are/were all clones... and I thought I was witnessing a live "selection of the fittest" drama. Anyway, I'll harvest the seed soon to start the next generation of coldhouse grown Lophophora williamsii ;-)

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Read the comments for a discussion on the use of the word "clone".

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