Friday, June 12, 2020

Humboldt Lily Thieves and How to Grow Humboldt Lilies from Seed

Photograph of Lilium humboldtii flowers
Meet the tallest and (in my opinion) most spectacular of the native Lilies of California, Lilium humboldtii ssp. ocellatum! This species grows up to twelve feet tall, from an underground bulb, bearing up to 70 of these brightly colored lilies on each stalk. They are in flower now in secluded and protected places along streams in California. This photo is from a wild plant on the edge of the San Fernando Valley. These are plants best grown from seeds, and if grown from seeds do very well in local gardens (see Propagation further down).

Here is a photo of me standing next to a tall, but not remarkably tall, specimen.

What happens when people find beautiful or wonderful things in the wild? Anything can happen. Most folks look and admire and take photos and memories, then move along.

A few have other reactions. They are one reason these plants have become hard to find in the wild. On the same hike my son and I noticed some lilies had seemed to have been broken off and left to die. This made both of us sad, then we noticed the holes and we became much more sad. Someone was stealing the plants!

The reason this made us more sad is that these bulbs are not like Daffodils, and they do not transplant well. Often wild plants have become enmeshed in the forest floor mycorrhizal network, a criss-crossing mesh of living fungal strands. These strands are a nutrient and water exchange system connecting most of the plants in the forest. Remove the lily from the network and the lily usually dies of shock.

What to do? Propagate!

Grow them from seeds, buy them from nurseries that have selected plants that do well in gardens, and protect the wild ones wherever you encounter them. You can get them from the Theodore Payne Foundation in Sun Valley, for example (though until their new online store is operational on June 16th the plants and seeds are not listed on their website, you have to call).

If you get seeds, the procedure to start them may seem odd, but is pretty simple.

Get a zipper seal bag, add a half cup of vermiculite, your seeds, and enough water to make the vermiculite moist but not so wet that there is any water collecting at the bottom of the bag. Put the bag in a drawer in your room - I use my sock drawer because it is farthest from the window and I go to it every day, so I don't forget the seeds. The idea is to keep the seeds room temperature (or around 70 degrees Fahrenheit plus or minus a lot) for three months. Yes, three months. Check them once a week to see if any are beginning to grow small white roots (this is unlikely to happen, but does once in a while - the seed that grows a root can be planted now - skip ahead for it but leave the others in the bag until they sprout). This is called warm, moist stratification.

Now put the bag into the vegetable drawer of your refrigerator for at least two months - once again, check the seeds often. As soon as they start developing white roots, they are germinating. By the third month (90 days) take them out and plant them.

We use troughs that are 8" wide, 6" deep, and 15" long. Make certain there is at least one good drainage hole in the bottom of the trough, or the plants will rot after germinating.

The soil mix we use is simple: 3 parts Pearlite, 6 parts Coir (coconut fiber - be sure to soak the bricks and let them expand first), and 1 part clean 80 grit silica sand (sandblasting sand). Mix it all together while the ingredients are moist enough not to make dust.

Once mixed, we put a small scrap of aluminum window screen over the drainage hole, then fill the trough with soil to within about one inch of the top.

We sprinkle the germinating seeds from the bag out onto the soil surface, with the vermiculite they were stratified in, and then gently cover with half an inch more of the soil mix and water immediately.

Keep the troughs moist but not soaking wet - too much water is as bad as too little with this species. They like bright shade, no direct sun, and as cool as easily possible. They live in deep, shaded canyons most often in the wild. After their first year, let them go slightly dry (no baking in the sun or going bone dry) in September and October. They will often push new leaves and stems up in January of each year, though this can vary quite a bit. Leaves can die down as early as July or as late as late September. Once the leaves die down reduce the water - let the soil surface dry out (no more than the top quarter inch or so) between watering.

I've flowered them in four years from seed, and had really amazing plants taller than me in five years.

Tuesday, June 9, 2020

A Classical Lemon Battery - without the Lemon

This is a classic - to build one, you need a citrus - any will work, this for example is an orange - and three (ideally zinc plated) iron things (screws, nails, or in this case some clothespin springs), and three copper things (copper foil used here).

Use a knife to make a pair of reasonably close (1/2 to 1" apart) slits in the fruit slices. Put one copper and one iron item in each slit. Then connect the copper tab on the first slice to the iron item on the second. Connect the copper tab on the second slice to the iron thing on the third slice.

You should now measure about 1.9 volts across the two terminals (the iron item on the first slice and the copper item on the third slice).

If you have a problem, recheck that everything has stayed in the citrus slices and that the clip leads are correctly connected.

Finally, connect a LED between the terminals.

In the picture, the yellow lead is the negative lead (iron item on slice #1). This connects to the shorter of the two leads on the LED (the negative terminal).

The white lead in the photo is the positive lead. Connect it to the copper strip on slice #3 and to the longer lead on the LED.

If everything is done correctly, the LED should light up - really, really faintly. To see ours we had to go to a darkened room and look. It was clearly lit up, yet faint.

If your diode does not light up, you may have the diode backwards. Try switching the leads on the diode. If that does not work, try a different diode (some need more than 1.9V to turn on).

Our diode is the faint bright dot to the right of the plate holding the citrus! As I mentioned, not very bright yet definitely on.

My son had this to say about all this: "I want to make orange juice, and build a bigger battery so we can make a heater". I do not know how many of these we would need to power a heater, but the number is large!

Friday, June 5, 2020

Germination of Dandya thadhowardii (?), a Mexican species of Themidaceae

Late last year I encountered seeds of a genuinely esoteric species of bulb from Mexico on offer on the web. It is actually a corm (a thickened underground stem that resembles a bulb). Since it is a Summer growing species related to Bessera, I decided to delay planting the seeds until I also planted my Bessera elegans corms for their growth season.

I believe it may be Dandya thadhowardii, though the species identification may have to wait a few years until the plants reach flowering size.

The seeds were planted on May 11th, and were all ready sprouting in the last week of May, though more seedlings have appeared in the past days. This photo is from June 3rd. I have been unable to locate any published photos of seedlings of this genus, so this photo may be the entire internet's worth of photos of germinating seedlings of this genus.

What strikes me about these is their very ordinariness. The California genera in the Themidaceae include Brodiaea, Dichelostemma, Triteleia, Dipterostemon, Androstephium, Bloomeria, and Muilla. These seedlings on basic appearance could be in any of those genera - a very familiar sight to us (we like the native bulbs and tend to start them from seeds). More famous kin from Mexico include Behria, Bessera, and Milla.

Some of these species are flowering in the mountains and coastal areas of California now and in weeks to come, as they often flower after the grasses dry. My son and I often go seed and lizard hunting together - he is very good at spotting many of our local species as seed heads, in some cases better than finding them as flowers!

One of these genera is Muilla. Muilla maritima is abundant in local populations in the San Gabriel and Verdugo Mountains (as well as much of California, for that matter). The flowers are easy to miss as they are lovely but pale and small, the seed pods are larger than the flowers and full of shiny black seeds - this species is easier to spot in seed than in flower!

Another one of my favorite local Themidaceae has recently been moved to a genus all its own:  Dipterostemon. Below is Dipterostemon capitatus, one of the cheerful and often abundant flowers of late Winter and Spring. When I was a kid growing up near Jet Propulsion Labs, the ones of these I grew at home often started to flower before Christmas.


Learning the plants that make up the thin green layer on our world can be a wonderful way to see the world in finer detail. Sports are often more fun when you know the players - landscapes have different sorts of players, knowing them can make a simple walk in the hills richer and a lot more fun as well. 

Maybe I'll make botanical Trading Cards....


Monday, June 1, 2020

Restoring an original Celestron NexStar 5

Late in 2019 my son and I bought a damaged original NexStar Celestron 5 from someone who had one that had fallen over. This was the very first of the NexStar telescopes, Celestron's first attempt to field a GoTo telescope that knew how to orient and align itself, and then how to find objects in the sky, all by itself.

Not all that many were made before it was replaced by an improved version, the NexStar Plus, a line of telescopes that are made to this day.

This being a relatively rare machine that was rapidly replaced by Celestron with newer and better telescopes, they no longer any sort of support for the model. We were on our own to get the machine up and running.

My son recently turned seven, so this seemed like a good opportunity to show how to figure out what was wrong and to repair it. While there are integrated circuits on the main board, they are modest and there are plenty of discrete components making probing and debugging relatively tractable.

In fact, the wiring can be traced just by holding the main circuit board up to a bright light.

What were the symptoms? The telescope would power up, and immediately start slewing in Azimuth. Altitude was fine, but with or without the hand controller attached the telscope just started moving at maximum speed clockwise (when viewed from above). The hand controller was erratic as well and the case showed signs of being crushed. The screen was intact, but flickered and was unreadable. The tripod had a broken support strut, and the focuser on the tube assembly had a great deal of play - to the point of wondering if it was doing anything at all.

Four related but separate problems.

The tripod we dealt with temporarily with a cable tie. The problem was the spider that holds the legs in  equilateral triangle had one broken coupling where they all meet in the center. Not elegant, we will machine or 3D print something better eventually.

The focuser likewise was a fairly simple fix: the screws were loose.

The main board was the hard part.

The main board had a single failed chip. It was the motor driver chip for the Azimuth motor. Finding it was accidentally easy - I happened to tap it while explaining to my son what some of the chips did (we looked the part numbers up online, I don't have this in my head...). When I tapped it, it burned my finger. This is an unsubtle clue to a problem.

That lead to grabbing the thermal camera and collecting more information. Fortunately, it was the only thermal anomaly on the board: apparently one of the motor driver H bridges had failed to being constitively on.

Using a SEEK thermal camera, this is what the board looks like after being turned on for about ten seconds:

The good news: only one conspicuously hot chip. The better news? It is a chip that we could still purchase. The chip is a Texas Instruments / L293DNE that we were able to buy from Digikey (not an endorsement, just the place we found them in stock). The Celestron NexStar main board has two of these in 16-pin DIP packages. One controls the azimuth motor (turns the telescope to different points of the compas) and one controls the altitude motor (raises and lowers the tube). Our failed chip was the azimuth drive.

The first task was to desolder the chip. Since the chip was dead, the legs could be snipped off next to the chip body and the chip removed. Then the pins can be desoldered one at a time. That would have been simpler than what we did, which was a classic chip extraction. After an hour of playing with desoldering wick, we had the chip out!

After the chip was extracted, we ran a very small drill bit through the holes to make certain they were clear (they are plated through, so do not use a bit that is even terribly close to the size of the hole or you will break circuits). We managed to cut one trace on the board as well, which we fixed with a solder bridge.

With the new chip installed, we are approaching readiness to reassemble and test the telescope! My son did all the soldering to reinstall the chip and most of the desoldering. He is proud of being able to fix his telescope.

When the whole thing was assembled, the telescope works, though the hand controller is often illegible. That is our next project!