Saturday, July 19, 2008

Testing Encephalartos Pollen

Testing Encephalartos sp. Pollen Viability  with Hang Drop Technique

I. Test setup, five samples per person at one time


  • Prepare spread sheet with information of specific species, year collected and specific plant number
  • Remove Pollen from freezer, where it has been stored at -15° Celsius.
  • Prepare Petri dishes, one nesting pair for each separate pollen package, washed with soap, rinsed and completely dry.
  • Ethanol to wipe inside of Petri dishes, then close immediately.
  • Prepare testing media, a germination solution of 65% sucrose and 15% boric acid in distilled water and store in fridge until used.
  • Glass pipette for pipetting solution drops into Petri dish
  • Distilled water, provide enough to seal Petri dishes and to soak paper towel in incubation tray
  • Set up ethanol in a small glass column for cleaning brushes between different pollen samples
  • 3 small brushes # 2
  • Colored permanent marker for labeling Petri dishes


Prepare a large tray, line it with paper towels and wet slightly with distilled water. Label the smaller of the nesting Petri dishes, abbreviating the species name, the year collected and the plant number (if applicable).

Start lamina flow cabinet, and place tray and all materials inside. From now on all work is done inside the cabinet to avoid contamination, which encourages growth of fungi and other problems, resulting in defective tests. Use latex gloves when working, and proceed methodical and as clean as possible. Lay out 5 nesting Petri dishes inside the tray in the right order and open them. Fill larger dish with small amount of distilled water, just enough to create a airtight seal when the small dish is placed inverted inside.

With pipette carefully place three drops of germination liquid in each one of the labeled smaller dishes, such setting up three tests per sample. Do not touch the tip of pipette with anything, as it goes back into the solution and could contaminate it. Do not make the three drops too large as they might ‘roll’ to the edge when turned over and placed in the larger one.

Fig. 1  Placing of pollen on to drops of germination solution

Open pollen package carefully and with brush remove small amount of pollen. Carefully tap brush one over each drop, making sure to have placed some pollen, but also avoid too much as this will result in a density of pollen in the solution that is very hard to count later on.

Then carefully turn Petri dish with the three drops upside down, and place inside larger dish with the distilled water. This is to seal the drops with the pollen from the outside so they won’t dry out during incubation.

When all Petri dishes are set up, cover with a second tray, remove very carefully from lamina flow cabinet, and place it into an incubator set at 28° Celsius for 48 hours.

Fig 2. Working inside lamina flow cabinet

II. Counting of Developed Pollen under Microscope


  • Incubated pollen in Petri dishes
  • Pipette for transferring pollen in solution
  • Slides and slide covers
  • Microscopes, set at a 40x magnification

Fig 3. Counting germinated pollen with 40x magnification


Carefully remove tray with Petri dishes from incubator. Open Petri dish with hang-drops, and turn over carefully. With clean pipette remove small amount of liquid from center of solution drop, make sure to pick up some of the wetted pollen, but nothing outside the drop. Pipette on to the center of slide and add cover slide over it.

Place prepared slide under microscope, a 40x magnification seems ideal.

Visual grid sample counting method is used as following. Start in one corner and move over sample in a systematic order, e.g. down and over, up and over, down and over, and so forth. Randomly choose 10 spots with at least 10 but ideally no more then 50 pollen grains.

Count all pollen that clearly developed from the perfectly round shape and clear center of undeveloped pollen, to an uneven shape showing a pollen tube protruding out from a darkened center. Then count all undeveloped pollen, and note all numbers on spreadsheet.

Fig. 4.  fully germinated pollen with long tube protruding. 

Fig.5.  pollen with darkened center and tube development starting, as well as completely circular undeveloped pollen with clear center

 Proceed with new slide and pipette to the next drop until all three tests in Petri dish are counted out, then continue with next Petri dish containing new pollen sample. Enter all results for the three replicate samples for each species sample into spreadsheet, combine and calculate an average percentage of developed pollen for each species.

Developed by Phakamani Xaba and De Wet Boesenberg 

Technicians: Karen Wall, Enrique January, Dodo Loechle

Tuesday, July 15, 2008

Wine Country and other Botanical Adventures

Wine Country and other Botanical Adventures

This weekend I spend in Winelands, in and around Stellenbosch as guest of fabulous Wim Tijmens, Emeritus Praefectus Horti, Hortus Botanicus and Landscape Architect, and old friend of even more fabulous Betty Scholz, Director Emeritus of Brooklyn Botanical Gardens. (I put their name in italics because I believe they are truly their very own species, and quite possibly in danger of extinction. Betty is of course endemic to this Cape region and now a beloved transplant to Brooklyn.)

After getting an hour late to Wim’s house because I did loose his phone number again and having only fragments of his address with me, I finally met this charming, lean, energetic and charismatic Dutch man. He immediately took me in his car to our first destination, Rustenberg, an immense and sprawled out estate, that grows famed wines and raises award winning jersey cows.

I had no idea this place is sooo beautiful! Driving through the gate Wim told me about his 13 years of living on the estate, caring for the wild part and the woodlands, and also having his hands in the gardens. As we entered the immaculate renovated and kept buildings where the wine tastings are held, people greeted him, and the current owner Simon Barlow came to meet us briefly. Wim is fond of telling everybody that he knew him as a puppy… We got to try some of their top wines, and they were delicious. Then we walked through the newly developed garden by Rozanne Barlow that stretches gracefully towards the river on the right, with grand views towards the mountains and False Bay. There was snow on top of these rocky mountains in the not so far distance, something that very rarely happens, and which made for some very special pictures, but also was the source for the very low temperatures! But the skies stayed without a single cloud, and the air was so clean and crisp, it seems completely devoid of pollution. Yes, the quality of the light here is very different, sharp and very bright, but also three-dimensional.

There was a gigantic labyrinth, and a reflecting pool with huge koi in all colors. They did have a rather sturdy black net covering the entire square, which is I would think a very good idea as those African Fish Eagles I saw before are perfectly capable of carrying away quite sizable pray!

We just strolled around, and other then Kirstenbosch where there is almost only Southern African plants, here you saw all the familiar cultivated Europeans, Americans, and Asians. Roses, hellebores, salvias, lavenders, ginkgo and boxwood, e.t.c, but the real freaky thing is that right between these grows a palm tree and snowdrops are in bloom next to the wild dagga, Leonotis leonurus and scabiosa, mid summer annuals in our parts of the world. This is wrong – and very irritating!

From there we drove on over the small Helshoogte Pass towards Franschhoek with more enchanting panoramic views of these rolling valleys, and snow covered peeks.

We stopped briefly at George’s, who is the horticulturist in charge of the small botanical garden belonging to Stellenbosch University, which is Wim’s work. Wim invited him to join us at Boschendal, another picture perfect wine estate, where we had a lovely lunch with some more wine, sitting outside in the courtyard under the old oak trees. The sun was out, but the air had very much bite to it, and looking at the snow in the distance did not really help that much! George had accompanied Wim on one of his guided botanical trips to China, and knew Betty from various occasions; a nice man with the very mellow disposition of a longtime gardener.

Wim and George

The story with the oaks here is very interesting! The colonists, after quickly chopping down most of the local Yellowwood (Pododcarpus latifolius) and Stinkwood trees (Ocotea bullata), and even burning Protea bushes for firewood, found themselves in desperate need of more trees. They appreciated these indigenous trees for their very durable and fine-grained wood, prized for furniture making and used extensively for floor and ceiling boards, but found them to be growing very slowly. So they thought of the most desirable tree they knew from back home, and shipped a large number of oak seedlings in little wooden caskets across the oceans. These oaks grew fantastically well and fast, but right there was also the problem. With the winters here being so mild, the oaks have a very short dormant period, barely loosing their leaves before pushing out new ones, which results in fast growth and very weak and lousy wood not suitable for building nor furniture making. And the infamously strong cape storms do easy damage to these, often decapitating and severely injuring the trunks, resulting in hallow and rotting specimen. On top of all this the oaks produced a large amount of seeds that readily germinated in this mild climate, resulting in a wide distribution of a basically useless tree. Kirstenbosch used to have a lot, planted by the previous farmers and even the first director, and the sale of acorns as pig food was a quite important source of income for the garden at the time. There are still quite a few left, and some are rather healthy and large specimen, but they are not being replaced once the wind and age take them out. So that’s the story of oaks in South Africa. 

After lunch we drove around Stellenbosch a little, and I realized the size of the University this otherwise small place has. The campus is very beautiful, and there are more than 23,000 students enrolled at the moment!  This university traditionally was very Afrikaans (meaning white only), but this is changing slowly with a colored (permissible language here) dean, and an increasing mixed student body. Of course being allowed to study does not mean at all being able to do so, many young and gifted people from the townships obviously have too much pressure to make money and contribute to the household, instead of accumulating student loan depths. And we did not see very many students as they have their winter vacation until the end of the month.

Back at the house it was time for a nap, and I browsed in the many interesting plant books that were lying around (I came across a fascinating book on SA parasitic plants). A small dinner, some wine and the burning wood in the open fireplace helped to take off the edge of the chilly night, and the stories about people and places that Wim knows from his work and travels kept me awake past midnight. Illustrious is a word that comes to mind!

Next day Sunday Wim took me to Vergelegen (meaning ‘out of the way’). This is yet another mind-blowing estate near Somerset West, and is considered one of the most beautiful estates in the world! Build in 1701 by many slaves from all over the territory of the Dutch West India Company, it has orchards and vineyards filling a whole valley.

The main axis allows your view to go all the way from the mountains, through the orchards, cutting the octagonal main corral (now the main garden) in half, right through the center of the symmetrical house and past the old camphor trees, into the Camellia collection and the woods with the river flowing by…Grand!

The 300 years old camphor trees (Cinnamomum camphora) in front of the main homestead are declared National Monuments, and they are truly monumental! These are not indigenous, but originally from Asia, where they are cultivated for camphor and timber production.

Walking around further we admired a moderately old but very hallow oak, and an absolute magical Podocarpus. This tree’s age is also estimated around 300 years, and its multiple stems, and branches wind and twist and bend along the ground. And further out, a perfect circle of seedlings surrounds the old tree, forming the most magical fairy ring you can find.

The buildings in comparison are rather small and modest in dimension, and simple in layout and design but exquisite and filled with many valuable antiques the different owners acquired throughout the centuries.

This is the old farm/slave bell under the camphor trees - a not so distant reality.

Now the estate belongs to a large mining company, the Anglo American plc group, which has some Oppenheimer sitting on his main board of directors, who took special interest in this place. On the guest list one will find (besides of the Oppenheimers) the Queen, Nelson Mandela, the Clintons, and me.

Again Wim knew almost everybody, and introduced me to the chief horticulturist who happened to lunch with the camellia hybridizer who had donated his collection a couple of years earlier to Vergelegen. With them was an American woman microbiologist who I had an interesting exchange about chromosome counting.

We had a lovely and elegant lunch on the terrace (more wine of course), talking more travels and plants, and when I took off to head back towards Cape Town I felt positively elevated and inspired.


Thursday, July 10, 2008

Weekend Road Trip

Weekend Road Trip

Friday I was supposed to drive behind Sija and Thumeka, along the N(ational)1 to Beaufort West, where we wanted to stay overnight with a friend of theirs, I wanted to visit the Great Karoo National Park, and they wanted to go on to Kimberly for the week. I was scrambling all afternoon as I was moving into a new room at Fynbos Lodge, and then it took really long until Thumeka got back from work. When we finally took off she then needed to do some more shopping for her family and son in Kimberly, after that something had to be picked up in town, and then we also did a detour via a township in Stellenbosch. As it was night by then, and heavy rainfall set in, driving on this to me unknown busy main road with oncoming traffic, became a very challenging thing.

But when traveling, the way I like it, plans are often made to be aborted. So it is always good to have a plan B, or come up with one if necessary. Reaching Laingsburg, about 300km from Cape Town, I happily checked myself into Laingsburg Lodge, leaving those two guys driving on through the night. Drinking a beer from the mini bar, live improved despite reading in a brochure all about the town’s unfortunate claim to fame, a catastrophic flood in 1981 that took 103 lives. I nevertheless had a good night sleep even with the rain going on nonstop outside.Next morning the rain was somehow lighter, and there were short moments of much brighter skies. After a few inquiries about road conditions I decided to trace my way back until R314, heading south towards Montagu, thus cutting through the western end of the Little Karoo. 

Now I was starting to have real fun! A small but decent road with hardly any traffic (I actually counted about 8 cars in 2 ½ hours), rolling through a stunning landscape, all succulents and small leaved low fynbos shrubs, and a handful of farms very thinly spread out. Lots of birds everywhere, from a Black Shouldered Kite to Blue Cranes, rivaling the diversity of the plant world.

I took my time rolling along, and whenever I stopped and got out of the car, the quietness was breathtaking. This truly is a large country as soon as you get out of the densely populated metropolitan areas, and this sense of space and solitude is what I was always associating with the continent.

Getting closer to the town of Montagu the farms became a little more frequent. Mostly vineyards with citrus and other not identified, because leafless, fruit tree orchards. Just outside the town I saw a sign for a place called ‘Die Stal’, a very homey little restaurant on a farm, where I was the only guest on this rainy winter Saturday. I had an incredible spinach quiche, possibly the best in my life, and enjoyed the peaceful rain-free moment. Definitely one to come back for more food!

I really liked this town after driving around a little, seeing lots of inviting restaurants, a really hip B&B, and realizing the hiking potential in the surrounding mountains. Ö…mental note!

Continuing on small roads along more vineyards and denser cultivated land, via Ashton and Bonnievale towards the N2. Lovely!

On the N1 I turned back west and headed into the sunset. No – seriously – the afternoon was getting late, and I was making a b-line towards Kleinmond on the coast. The road lead along more inspiring landscape with the white cloud shrouded blue mountains to my right, and the occasional rainbow appearing to my left. Honestly true!

Kleinmond is the town just before Betty’s Bay, where I was planning to visit the Harold Porter National Botanic Garden the next day. But what a strange place! Mostly weekend houses, and permanent residences for retirees, living in rather unattractive houses arranged in square streets, reminding me of low income American suburbs, or German 50’s ‘Wohnsiedlungen’. And then the B&Bs I checked out – so depressing I drove right past them, including one ‘House Bavaria’ that reminded me of a neighbor’s house just north of the train rails on Muenchner Strasse, in my home town in Grafing. Horror!

Finally a found ‘Villa le Roc’, just a few meters from the rocky fynbos shore, which redeemed any human atrocities, and I took a late stroll sticking my hand

 into those waters already warmer from being a mix of Atlantic and Indian ocean. I guess I can’t claim yet to have touched the Indian Ocean, as it officially starts only beyond Cape Agulhas.

The lovely hostess suggested to offer the other party that had just arrived from a long hike a ride to the restaurant in the harbor, so I ended up dining with a father, his teenage son and his school friend. He is an ex opera singer, that was living/working in Germany for some years, who has a sculptor brother living in Brooklyn, we had a friendly chat, and then went back to the B&B. I don’t quite get people here yet…

I was not ready to call it a night, so I went walking to the ‘main drag’ (= 1 video store, 1 grocery, 1 bar) on the look for a bottle wine to bring back for a relaxed evening in front of the TV. Instead I ended up having a whisky-pit-stop in the local bar, and buying more Rooibos tea for the lodge.

In the morning it was raining like crazy, and it did not want to stop. Big deal; it was Sunday, so just perfect to brew another thermos of tea and stay in bed reading, waiting for better weather. I actually had to take a little late morning nap just because…then around noon it actually started to clear up. A long walk through that coastal rocky Fynbos madness (did anybody mention the insane diversity yet?) took me back to the harbor, where all the cafes and stores were open, and had about 1 ½ visitors, and I enjoyed a fine Latte at Potter’s Garden.

Then I got the car and took off to Harold Porter NBG in Betty’s Bay. This garden is so much smaller then Kirstenbosch it is almost disappointing at first sight. Plus there is a lot of construction work going on, the new visitor center and restaurant looks almost finished, it was a little off putting. I took the path towards the waterfall, and that was not small by any means. All the rain had even the smallest of rivulets swollen to a stream, giving a real strong acoustic background to the very scenic location. This garden’s strength, at least at this time of the year, lies in the mountain slopes and valleys, and there are quiet easy trails throughout. I did not see a single of the infamous Baboons, but again lots of birds andand a few amazing rare little gems like this: Crassula capensis, Crassulaceae the Cape Snowdrop. It is tiny, just about 2-3 cm (less then one inch) overall! Love it!

Then two Sundews right next to each other: Drosera trinervia and Drosera hilaris, The small ground hugging Little Sundew will bloom white, and the rarer upright is a pink blooming Sundew, but not quite yet – September is the month. But who cares about flowers with these…




Next stop was Stony Point, a protected African Penguin breeding colony. These guys felt truly protected, and were all over the place with their offspring, making these sounds that gave them their name of Jackass Penguins…

And in between Rock Hyraxes, also called Dassies, a hungry not so small rodent, and plenty Cormorants, the White Breasted and the Cape Cormorant.

A real fun noisy and smelly place, and those penguins did not miss one photo-op!

From there a real classic, scenic coastal road leads to Gordon’s Bay, which has a marina with quite a few little food places, another place for that mental Ö note…

I bypassed Strand, which at least from the distance looked totally unappealing with it’s ugly hotel and apartment towers, and took N2 to where it branches into R310 and goes back to hugging the coast until Muizenberg. Large dunes that are covered with these solid plant cushions stretch along to your left, a lot of them protected areas, it looks almost artificial. Especially because to the right are the Cape Flats, home to the immense Townships of Macassar, Harare and Khayelitsha, shags and (much less) tiny one-room houses as far as the eye reaches.

I ended this great trip by treating myself to a fancy dinner at ‘Restaurant Paradiso’ in Cape Town. Soupe au poisson, and Ostrich Bobotie. Yeah! Life is good

Thursday, July 3, 2008

Cycads, Strelitzias and Clivias

Cycads, Strelitzias and Clivias

This morning I met up with Phakamani Xaba, who is in charge of the ‘Dell’, the central section in the garden containing the Cycad/Gymnosperm collection, the Useful Plant Garden, and the Pelargonium Collection. He also oversees the collections in the Nursery for all Cycads, Strelitzias and Clivias. I accompanied him walking the garden for a few hours, and watering the Cycad seedlings, listening to a huge amount of info I am still processing.

For the next two weeks I will be working with him and Diky, a guy working at Kirstenbosch since 30 years (!) and taking care of the cycads since almost as long. What a source of experience I will have the chance to tap into!

This is Diky with a female Encephalartos sp.

We will be doing pollen collection, hand fertilizing, and doing general repotting and caring. A special project Phakamani is doing is aimed at establishing the cause of low seed germination rates (less than 10 percent) in Encephalartos latrifrons and developing methods to improve its germination rate. E. latifrons is a threatened species occurring in the Eastern Cape Province of South Africa, and E. latifrons ex situ has been cultivated in the living plants collection since 1913. Part of my project working with Phakamani for those two weeks will be testing Encephalartos sp. pollen for viability.

As for the Clivias, mainly Clivia minata,I have to say they don’t do much for me yet. They are a South African plant, but they seem a little like daylilies; a flashy colored drive-by-plant, that hybridizers obsess about when they breed a slightly different shade of orange into the second petal from the left…but I have to be careful, this would not be the first time I undergo plant-conversion, and there are quite a few different species.

Strelitzia reginae Srelitziaceae

In contrast, I can see much more in the Strelitzia reginae breeding efforts done here by Phakamani and Diky. The Strelitzta is the signature plant of Kirstenbosch/SANBI, and the garden has successfully developed, and introduced into the market a yellow (instead of orange) selection, they named ‘Mandelas Gold’ after Nelson Mandela, who visited the Garden a few years back.

Now there are selections being done to develop a very red form, and a dwarf strain. Besides of this, there is research conducted priming the stamens with various potions (sucrose, enzyme solutions,…) to improve fertilization and seed set.

open Strelitzia pollen sacs with pollen, the stigma partially visible on the left

In the afternoon 4 of us went out with a van to Grassy Park, an old and established Township (first sign of something like a middle class) in the Cape Flats, where we went to the house of Richard and Brenda, a lovely older couple that called up Phakamani to donate a large cycad growing in their garden for the last 20 years.

It turned out to be a male Encephalartos altensteinii bearing two large cones, shedding pollen all over. We, (mostly the guys, while my job was chatting with the owners, talking about all the international volunteers they housed over the years among other things) cut off all the leaves and the cones, and dug the thing out, removing almost all of a extensive root system! No ball & burlapping needed, these cycads take transplanting very well, and you can leave them ‘naked’ like that for over a week, before replanting, without a problem. Envision the massive underground trunk, ca. 2 feet deep, and about 1 ½ foot in diameter, and add about the same mass for the above ground trunk. When you consider this is a plant that stores large amounts of water, just imagine what the beast weighted in the end!!

There is a recent pest problem in the Cycad collection outside, some borer attacks the crown of some of these very old (several hundred years!) specimen. This mainly happens when there is too much moisture, which weakens the plant. Then these insects bore right in, resulting in a very fast rotting of the crown, it getting all soft, and only noticeable when the cycad drops all of its still green leaves within days, and dies. They have adopted a regiment of removing all dead tissue down to the ground or main stem, and paint the wounds with a tree sealant. They also spray the crowns and stems very regularly with some insecticide, and hope that no more of these hardly replaceable cycads will fall to prone to that pest. Eliminating the irrigation in this section, and not planting water-loving plants between the cycads, might be the most important measure taken, as this pest only takes advantage of an already weak plant.

Leaflet arrangement in Encephalartos horridus - a very appropriate name!

Wednesday, July 2, 2008

Hike up Table Mountain

Hike up Table Mountain

Sunrise over Cape Town

On the Internet I found this group of hikers, that invited me to come along on a hike on Sunday morning. We met up on the parking lot on Kloofnec at 7.45 am, right after the turn off to the Cable Car going up Table Mountain, which I found perfectly in my new wheels, and as a matter of fact it took me only 15min from Kirstenbosch. Distances aren’t very great here, as long as you have a car, otherwise this would have easily taken me anywhere from 1 – 1 1/2 hours!

A lively group of about 8 over 50 year olds was meeting there, and we carpooled from there to Camps Bay. One of them turned out to be a Rucksack Deutscher (=second generation German) from Namibia, and another guy was a true ‘Biederman’ from Mainz/Germany, a Math and IT teacher at the Cape Town German School, where he is with family for a 8-year contract. One of the women was a really bitchy maniac, and another kept mentioning a recent trip to Dubai, and her brother who is currently in Tokyo for the G-8 meeting (!!). Not really my kind of people under normal circumstances, but maybe therefore even more interesting to listen in to their stories and comments relating to this place and the people.

There are a lot of trails on this mountain, so I can’t tell you which one exactly we took. They started out with quite a fast pace which should have tipped me off right away, but instead of slowing into a more reasonable speed when we got to the very steep climb, they just kept running even faster! It turned out they were a bunch of exercise maniacs that wanted to be back down for a late breakfast!! Well, that was not exactly what I had in mind, especially on a gorges day like this, and in this absolute fantastic landscape with mind blowing incredible views. Plus I am in good shape, but not like this. It was very cold and super windy up on the plateau (I saw some ice!), but if one would have wanted to, you could have found a spot to rest and really take it all in. So I did what I could keeping up with them, and basically made lots of mental notes of things to come back to and look at again another day.

But it is fun to go out and test what I have absorbed of the flora so far – actually more then I thought! And to see all these Proteas growing on these steep rocky slopes...and everybody is talking about the colors coming soon in spring (starting August), really feeds into the expectations.

Rest of the day I enjoyed zapping around town, and explored some more of the coast.