Friday, April 24, 2015

Review of plants for the final examination

The final examination in ethnobotany class is based on the concept that an ethnobotanically learned student can walk through their environment naming plants and describing uses of such plants. At the end of such a walk an observer would conclude that the student knows their plants and the uses of those plants. This final is made uniquely possible by the location of the course here in Micronesia with students who are the indigenous peoples of these islands.

Surrounded by Ischaemum polystachyum, with Senna alata in the background, Saccharum spontaneum in the background on the left. The usual hike: forging through a sea of paddle grass looking for plants. Lerina, Darlene, Patty, and Simon in front of the Senna alata Merremia peltata can be seen atop the paddle grass. Each plant visible has a use. The white basal core of paddle grass can be used to soothe an upset stomach, young Senna alata leaves are a topical anti-fungal, the wild cane grass is used to weave a special fafa basket in Kosrae.

A large Asplenium nidus fern in a Falcataria moluccana tree trunk notch. The leaves seen are not those of Falcataria moluccana but rather of Macaranga carolinensis. Bambusa vulgaris is in the background to the right. The tree in the left background may be Pterocarpus indicus.

The class looks around at the profusion and confusion of greenery and tries to sort out local names, Latin names, uses.

Alpinia carolinensis - giant Caroline island ginger plant - on the left.

Lina Lawrence, Marvin Bartolome standing in the Haruki garden.

About a month ago the one cycad on campus (introduced) popped a cone. Two weeks ago can be seen above, the cone being about two to three weeks old (estimated).

Two weeks later and the cone seems to be maturing, opening up, the scales are becoming loose.

The cycad is still very short, permitting photos from directly above.

Thursday, April 23, 2015

Flying disks and mathematical models

An exploration of mathematical models and flying disks form the core of laboratory fourteen.

Vancyleen Wichep, Jerisse Salvador, Amabella Soram with disks

Laboratory fourteen explored the use of data to determine mathematical models and to test whether flying disks and rings outperform the theoretic performance of a non-flying object.

Marlynn Fredrick, Natasha Edwin

The first question examined was the nature of the mathematical model - does a horizontally thrown disk or ring travel a horizontal distance d that is linearily related to the horizontal throw velocity v? The velocity will be the independent variable on the x-axis, the distance will be the dependent variable on the y-axis.

Isako Sohar, Vancy, Kepueli Kurabui,and Marlynn

The second question was whether a disk or ring can outperform a ball or rock. A ball or rock travels a distance d equal to the horizontal distance times the square root of two times the height divided by the acceleration of gravity.

horizontal distance = sqrt(2h/g)*horizontal velocity
My directions were to throw the disks at my head

One should not get confused by the square root sign, the quantity sqrt(2h/g) is a constant that is roughly 0.45 seconds if h is one meter. That suggests a linear relationship.

If the disk or ring actually generates lift, then the distance should be greater than predicted by sqrt(2h/g)*horizontal velocity and the resulting slope should be greater than sqrt(2h/g).

Isako throws

Note that a throw velocity of zero meters per second generates a zero distance, thus (0 m/s, 0 m) is also a data point.

Marlynn, Isako, Jerisse

Along the way I discovered that some students had either never thrown a flying disk or had only thrown a flying disk once or twice. In hindsight I should have given instructions on how to throw a flying disk and flying ring. Aim was also an issue, very few students - even when they tried - could put the flying disk or ring dead onto the radar gun.

Williamson captured this photo of a lawn visitor who some of the female students find frightful. If some of the male students frightful of toads, they did not let on.

I have a calculator in my right hand, I forgot to print out the kph to m/s conversion table for the 8:00 class

The morning 8:00 data was surprisingly linear and exceeded the 0.45 to 0.55 estimated slope for a thrown ball or rock. I suppose to really complete this laboratory tennis balls ought to be thrown, but how to get them thrown arc free? With zero launch angle? Ideally a discus would be used, being double curved the lift cancels out. No discus. Maybe I can find a round barbell free weight to be flung. That would bring a new urgency to getting out of the way of the throw.

Bilrose Optaia records data

Lesleena ready to throw a flying ring

Wednesday, April 22, 2015

Banana patch clean-up two

On the 21st of April the ethnobotany class worked on cleaning up the banana patch once again. Clidemia hirta is completely out of control in the banana patch. The whole place may have to be hand pulled, sans knives, to try to get the C. hirta back under control.

A mapping exercise was also engaged in, but the GPS units were simply not accurate enough to correctly map the locations of the bananas.

Herpelyn Ilon and Patty Mario

Alexander Kenrad

Beverly Billy tackling C. hirta the only effective way to do so

Darlene Charley

Petery Peter, Bryan Wichep

Possible uhten in Ruhk

Located in the corner at N 006° 54.673' E 158° 09.332', thought to be Daiwang (Taiwan banana, local apellation, not necessarily from Taiwan).


Lilina Etson, Miki Fritz, and Bryan Mwarike moved an uhten lihli sucker to N 006° 54.663'    E 158° 09.326'. Identification by Lilina. Lilina calls the banana "Miki's banana."

Costus speciosus aka Cheilocostus speciosus in the foreground of Miki's banana

Lina Lawrence rakes

Yet to be identified banana, the third one fruiting on the 21st.

Banana flora for Pohnpei.

Floral litmus solutions

Physical Science SC 130 laboratory thirteen collected flowers and boiled them to generate floral litmus solutions. Some flowers generate solutions that function both as red and blue litmus paper simultaneously - that is they change to two different colors when a base or acid is added to the floral litmus solution.

Episcia cupreata proved to be an inconsistent indicator, not always changing in the same way for different bases

Baking soda was used to determine whether a floral litmus solution changes color in the presence of a known base. Baking soda is the known base. The students use a variety of local key limes as the known acid.

Boiling flowers

Chemistry is a quick run from proton and electrons, basics of atomic structure, hydrogen to oxygen, and then the structure of hydrogen and hydronium ions, providing an attempt at a segue into this laboratory. This material always reminds me that physical science is a bizarre course, an assembled beast that has way too much material in it.

Jerisse Salvador
A salmon color usually results from the presence of excess hydrogen ions - an acidic solution. Flowers that work as floral litmus solutions tend to turn magenta, pink, or red hues in the presence of acids. In the presence of bases the solution may turn blue, steel blue, green, dark blue-green-gray, or almost black.

Lynnsey Sigrah tests unknowns

Once the students have either one litmus solution that detects acids and bases, or two solutions one which detects bases and one which detects acids, the students use their solution to identify whether unknown materials are acidic, basic, or neutral.

Viola, Gisele, Midson

Saturday, April 11, 2015

The search for Clidemia hirta and Melastoma malabathricum

With the ongoing development of the soccer field, finding Melastoma malabathricum var. marianum proved challenging. Clidemia hirta was easier to find, the trek to find Melastoma malabathricum var. marianum involved traipsing through the swamps of Palikir. I headed down to the present entrance road/construction access road to avoid the cliff that exists along the southeast side of the soccer field. I then doubled back to the west edge of the soccer field, walking north just to the west of the west edge. The day had been rainy and I knew there was soft terrain further to the west from prior explorations. I also knew the west edge would be fairly firm.

Miki Fritz was one of the student's in the lead through the north edge fallen tree field

At the north edge of the soccer field are all of the downed Falcataria moluccana (tuhke karisihn) trees cut to clear the soccer field. These trees trunks and branches are covered by Ischaemum polystachyum (reh padil), This makes for very treacherous footing, especially for those in the lead. One winds up with one's leg falling inbetween hidden trunks and branches in the tall grass.

Lina and Elizabeth emerge from the paddle grass into the forest

I knew that once across the fallen trees, the ground on the other side would be swampy. I asked the class to wait up at the soccer field while I went in to look for and retrieve some plants. No sooner had I clambered over the fallen trees and down into the forest than I turned to see the class dutifully following me into the forest.

In the shade of the forest was Dissotis rotundifolia, the third member of Melastomataceae seen on this wallow through the swampy forest.

The forest floor was more open than it might appear, and many small informal trails wandered hither and thither through the area.

Clidemia hirta was found back to the east from where I entered the forest, I did not see Clidemia hirta towards the west. Not obvious is that at this point the students are standing in a temporary stream running down and alongside the informal track we were on. I do have to remember to warn students not to wear fancy stylish shoes on these outdoor hikes.

Elizabeth, Lina, and Jamie examine the Clidemia hirta

Selfie with Clidemia hirta, Daryll photobombing from behind.

The crew slogs on through the forest: at this point no pisetikimei has been seen. One student who knew pisetikimei had asked whether the Clidemia hirta might be pisetikimei. Until one sees them next to each other, one cannot learn to tell them apart.

Bryan Wichep and Bryan Mwarike push on through an open area of paddle grass. Probably a useful location for hide and seek in physical science, just the challenge of getting into the area without being seen.

Lilina, Kohsak, Lina, Herpelyn, Esmirelda. Bamboo in the background, small rivulets of rivers underfoot. In moving east the class hit an area where streamlets ran over the ground. Pushing ahead meant wet feet and possibly sinking deep into soft muck. I again asked the class to wait while I scouted for a route ahead. I could see a tree with a large Huperzia phlegmaria plant on the trunk, I wanted to get a closer look at the tree and the area around the tree. That meant fording the temporary stream running between the class and the tree. No sooner had I crossed the stream and reached the tree than I found the class my shoulder.

Following Petery into the Cyrtosperma merkusii, giant swamp taro. A sure sign that underfoot will be wet at best, quick mud at worst. The terrain proved wet but firm.

A fern that I have yet to positively identify. Not Microsorum scolopendria.

Franson amid the Cyrtosperma merkusii.

Lina Lawrence, wet, smiling. Elizabeth and Patty behind her.

More images of the fern. Could not find a fertile frond to image.

Back up out of the forest, hoping to find pisetikimei in an area with more sunlight. Daryll, Stephanie, Beverly, Lina, and Lilina.

Daryll would hit pay dirt down in a gully off of the northeast corner of the soccer field: Melastoma malabathricum var. marianum (pisetikimei) in his right hand, Clidemia hirta in his left.

Three emerge from the forest.

Herpelyn brought an umbrella, but the wet was under foot, not overhead.

Dressed for style in the swamp: Beverly Billy, Patty Mario, and Esmirelda Elias clamber up and out.