Hoverfly visiting a flowering Escobaria vivipara (Alberta, Canada) cactus

While preparing a post on the cold-hardy cacti I'm growing in flower boxes on my balcony I stumbled upon this high-speed video I shot last summer. The video shows a hoverfly visiting a flowering Escobaria vivipara (Alberta, Canada).


Hoverflies, sometimes called flower flies or syrphid flies, make up the insect family Syrphidae - a group of superbly beneficial insects, the adults being pollinators and the hoverfly larvae being predators of aphids and other damaging insect pests and their larvae. The coloring and movements of most species mimic bees or wasps giving them some protection against being eaten by birds.

I’m by no means an entomologist and to my untrained eye the flower fly in the video looks like a Scaeva selenitica (a common European species of hoverfly) with its three pairs of yellow comma markings on the abdomen. If you are an expert on insects and recognize the fly I would be happy to know the exact species.

If the above video doesn’t embed properly you can open it in a separate window by clicking the image below.


Hoverfly (Scaeva selenitica?) visiting flowering Escobaria vivipara (Alberta, Canada)

The high-speed video was filmed at the end of June 2012 using a Nikon 1 J1 camera.

TimeScapes: Death is the Road to Awe

I'm fascinated by time-lapse videos - especially the ones that include cactus related footage. Tom Lowe is a great inspiration when it comes to time-lapse filming and has recently released the movie TimeScapes that features stunning slow-motion and time-lapse cinematography of the landscapes, people, and wildlife of the American South West.

Tom has made several clips available on Vimeo including the one below featuring giant saguaro cacti (Carnegiea gigantea) reaching for the soaring night sky.



If the video doesn't embed properly you can view it in a separate window by clicking the picture below.


Saguaro cactus (Carnegiea gigantea) lit by a military drop flare

A particularly epic sequence is filmed on the East side of the US Air Force's Goldwater bombing range near Ajo, Arizona, and shows a saguaro cactus (Carnegiea gigantea) towering in a desert landscape painted by the lights from military flares dropped from planes.

The above picture is courtesy of Tom Lowe @ Timescapes' photostream (where you can find a lot more beautiful photos).

Time-lapse video of a flowering Ariocarpus kotschoubeyanus var. macdowellii cactus

Flowering Ariocarpus kotschoubeyanus var. macdowellii (SB 100; El Pilar, Coahuila) - please note that the time-lapse video is generated with a fairly high frame rate meaning that you can slow down the video to 0.5x its speed (or even 0.25x) with good results - the playback speed is controlled via the settings for the YouTube video.

As mentioned in the previous post I broke the shutter of my old faithful Nikon D70 SLR camera while capturing photos for a time-lapse video of a flowering peyote. A time-lapse video of just a few seconds duration requires hundreds of photos and thus imposes a considerable wear on SLR cameras with mechanical shutters. Consequently I have avoided using my new SLR for time-lapse shooting and instead experimented with alternative solutions. One of these being iTimeLapse Pro for the iPhone - an app that allows you to control basic settings like the capture interval, when to stop and start capturing images, and the capture resolution.

The app was used for shooting the images for this video and as such functions just fine, but I still need to work on enhancing the steadiness of the phone (it slid slightly on its stand during the capture sequence), and on tuning the focus (which is slightly behind the center of the flower, making the flower itself look blurry). Also the images are taken in natural light that changes continuously giving the video a flickering appearance - on the other hand the change in light is also responsible for the flower closing again, adding to the video.

I also shot photo sets for a flowering peyote ( Lophophora williamsii var. echinata) and a Gymnocalycium calochlorum and will generate and upload time-lapse videos for these as time permits.

For the technically inclined it must be mentioned that the video was generated using FFmpeg, a free set of tools to record, convert, stream and play multimedia content. FFmpeg can be downloaded here. The photos used in the video were shot one every 15 seconds and is played back at a rate of 25 images per second. The time-lapse video comprises 1001 still images.

If the video doesn't embed properly you can view it in a separate window by clicking the picture below.

Peyote in the sky...

Time flies... as do the clouds in the above video. 8 years ago today this blog was started off with a test post featuring a picture of a field of Cylindropuntia bigelovii photographed in Joshua Tree National Park (maybe I should do another C. bigelovii post as I have lots of beautiful pictures from that and later visits to the park ;-)

As a curiosity it can be mentioned that I broke the shutter of my old Nikon D70 doing the above time-lapse video a couple of years ago. The video is rather short (as the shooting ended prematurely) and doesn't show the flower unfold, but I thought it would fit nicely with this post, illustrating the passing of precious time.

If the video doesn't embed properly you can view it in a separate window by clicking the picture below.


Peyote in the sky...

Lophophora diffusa swelling with water, time-lapse video

I'm keeping my plants completely dry during their winter dormancy and consequently they are rather flaccid come spring. The following time-lapse video shows a couple of my larger Lophophora diffusa plants growing turgid after having their first drink of water in several months.



In a fit of thoughtlessness I also watered the Bowiea volubilis visible in the background. This plant also started to expand generating visual “noise” that makes it harder to see exactly what moves when and where. To amend this mistake I inserted the white markers that act as fixpoints showing how much the cactus will have expanded by the time the video ends.

The pictures used for the time-lapse video were taken over a period of 88 hours starting March 6, 2009 in the afternoon through March 10 in the morning. A picture was taken every 15 minuttes giving a total of 352 photos; these are played back at 24 frames per second resulting in a video lasting slightly less than 15 seconds. Another piece of technical trivia is that each second of the time-lapse video corresponds to 6 hours real-time.

The pictures used for the high-definition (1280x720) version of the video above were cropped to obtain the 16:9 aspect ratio. A time-lapse video based on the uncropped and unmanipulated photos (without white markers) is shown below.



The swelling of the plants is not as evident as I had hoped for so I might try doing another “swelling with water” time-lapse video again next year – this time starring some of the plants from my coldhouse (as they are drought dormant for a longer time than my windowsill grown plants). Also the flickering, caused by the shifting light conditions during the day, is a bit disturbing. If I do a video like this again I'll see if I can avoid ambient light completely.

Flowering Lophophora diffusa, time-lapse video

I took the pictures for this time-lapse video of a flowering Lophophora diffusa in early May, 2008. I can't quite remember why I decided to not publish it back then – I was probably disgruntled by the glitches (a couple of seconds into the movie you can see the plant shift a bit, and after 14 seconds there's an abrupt change in focus) and decided I could do better. Anyways, I never got around to doing that and now, after all these flowerless winter months, the small errors don't seem to matter ;-)



The L. diffusa flower opened amazingly fast. The time-lapse video covers a time span of only 45 minutes and is made from 154 still photos taken at intervals of 15 seconds; the photos are played back at a rate of 10 photos per second (the attentive reader will notice that the above numbers don't add up – the focus change 14 seconds into the video indicates a problem that resulted in loosing images for a period of approximately 6 minutes)


Flowering Lophophora diffusa, time-lapse video

The plant was bought just a couple of months prior to these pictures being taken, as described in my post on a Lophophora bargain.

Update - March 28, 2009
You can now watch the flowering Lophophora diffusa in blazing high-definition ;-) I cropped the photos used for the time-lapse video to a size of 1280x720 in order to make the 16x9 HD movie shown below.

Time-lapse video of a flowering Lophophora williamsii

I've been away on a short vacation and it seems my grafted Lophophora williamsii (SB 854; Starr Co, Tx) has spent its "lone time" wisely and grown three flowers.


Lophophora williamsii displaying three flowers

Even though the flowers were already quite open when I returned home, I decided to attempt a time-lapse video showing the flowers open fully. Unfortunately I forgot to disable the cameras autofocus function which gives the video a shaky appearance as the camera continuously changes focus slightly.



That being said, I'm impressed by the agility of the Lophophora stamens - they seem almost to be dancing around the style. A dazzling display of thigmotropic behavior is shown 50some seconds into the video; the stamens are disturbed and fold rapidly in around the style only to resume their perpetual wiggle shortly after. In contrast to this Epithelantha micromeris v. greggii stamens never seem to move during flowering.

I yet haven't managed to create a time-lapse video that is fully satisfying (the flower must be shown from bud to full bloom, the image must not shake/autofocus, no drop outs must occur in the stream of images, etc). I'll keep trying though, but I'll bet that when everything is set for the perfect time-lapse the shutter of my good old D70 gives up the ghost just before the shoot is finished ;-)

The photos for the time-lapse were shot at intervals of 15 seconds during a period of 160 minutes. The pictures are played back at a rate of 10 frames per second, i.e. the flowering is speed up by a factor of 150 resulting in a video running for 64 seconds.

Time-lapse video of a flowering Epithelantha micromeris v. greggii

Most of my coldhouse grown Epithelantha micromeris v. greggii (Cuesta la Muralla, Coahuila, Mexico) flowered big time this week. The plants were started from seed in 2004 and are flowering for the first time.


Flowering Epithelantha micromeris v. greggii

The small creamy, off-white flowers are not spectacular but still quite a beautiful sight, especially when several are blooming at the same time. The following time-lapse video shows a flower going from bud to full bloom.



The pictures used for the time-lapse were taken every 15 seconds over a two hour period. The pictures are played back at a rate of 10 frames per second, i.e. the flowering is speed up by a factor of 150 resulting in a 48 second video. The camera was placed on an old wooden floor resulting in a couple of "wobbly" sequences. The photos were taken using natural light only, the shifting light levels are caused by drifting clouds.

I attempted to cross-pollinate several of the plants and are hoping for seeds next year.

Time-lapse videos of a flowering Lophophora jourdaniana

I’ve previously made an attempt at a stop-motion video showing the thigmotropic behavior of Lophophora stamens. It so happened that the Lophophora williamsii var. jourdaniana plant flowered again during my summer vacation, leaving me plenty of time to experiment with time-lapse videos.

The first video shows the Lophophora williamsii var. jourdaniana flower unfold (I’m not exactly an early bird so I missed the first part of the unfolding ;-)



The above video covers a time span of approximately 90 minutes, i.e. playback is sped up by a factor of 150. This is my first attempt at a time-lapse “flower movie”, as can be seen by the quality of the film. The first 11 seconds were shot while the camera was in auto-focus mode, resulting in a “wobbly” feel. I then disabled auto-focus (and lost a couple of frames in the process, which can be seen as a “jump” 11 seconds into the video) and later had to re-focus (28 seconds into the video), so it's not perfect, but not bad either. The frames were shot with the sun as the only source of light.

Next, I wanted to make a better (i.e. more frames per second) version of the thigmotropic stamens video but ended up with a version looking a lot like the original one.



The playback of the above video is sped up by a factor of 12. Unfortunately I stopped taking pictures just as the stamens started to revert to their original position. In an attempt to achieve more frames per second I played around with my cameras continuous shooting mode. Suddenly the flower was visited by an industrious bee beautifully illustrating the purpose of the touch sensitive stamens ;-)



I guess the last 2 clips would be more illustrative if they had been filmed with a regular video camera instead of an SLR, but they’ll have to do for now. Unfortunately my camera ran out of power effectively putting an end to the filming of this particular flower.

Finally I have to mention the Hydrocactus – cactus video page as the main inspiration for these experiments and the best source of cactus videos I’m aware of.

Flowering Lophophora jourdaniana, take two.

One of my Lophophora williamsii v. jourdaniana plants is flowering again – this time with the full cooperation of the sun, resulting in a much more well-developed flower compared to the previous one.


Flowering Lophophora jourdaniana

My two Lophophora williamsii v. jourdaniana plants are almost in full compliance with Habermann’s description (rose-violet perianth, pistil, and filaments; persistent spines on young areoles) but the open flower clearly contradicts Habermann’s claim of cleistogamic flowers (i.e. flowers that do not open and are self pollinated). Apparently Habermann misunderstood or used this term incorrectly as the photo accompanying the type description also shows a plant with an open flower ;-)


Lophophora jourdaniana – thigmotropic stamens

Like many other species of cacti (including the other Lophophora species/varieties) L. jourdaniana has thigmotropic stamens, i.e. stamens that when touched fold in around the style (as is evident for the front stamens in the rightmost picture).

The following stop motion video provides a better illustration of the thigmotropic mechanism - I'll try to make a higher quality movie the next time the plant flowers.



References
Vlastimil Habermann (1975), “Lophophora jourdaniana Habermann species nova”, Kaktusy 11 (1), 3

Flowering Ariocarpus fissuratus var. hintonii

None of my Ariocarpi have flowered yet, but this video (1.1MB) of a flowering Ariocarpus fissuratus var. hintonii gives a good impression of what to expect.


Flowering Ariocarpus fissuratus var. hintonii

More amazing videos of flowering cacti can be found at the Hydrocactus video page.