Monday, December 5, 2016

Unity College Dartmouth Greenhouse Week 6 (Final)

Week 6: 11/28/16-11/30/16: ~ 8.2 hours extra; Total hours= 188.2 hours worked on site

I can't believe that this was actually my last week working at the Greenhouse as an intern. Time itself seems to have travelled so fast.  I have had the pleasure of meeting and working with some really great people over my time as an intern.  This has been very enjoyable experience for me.  I feel as though I have learned a lot and not just in botany or entomology but in the networking and organization required for a full-time job with out a drivers license.  I had so much support from the people surrounding the greenhouse, whether it was my rideshare driver or the maintenance staff or the OSHER botanical illustration class!

Probably the most popular and noticeable plant that we have in the Greenhouse is the 'Corpse Plant' or Titan Arum (Amorphophallus titanum, Family: Araceae) (I will not be explaining the meaning of this particular scientific name as I am unsure it would be suitable for the blog.  Those of you who understand the later part of the genus name can guess why I say that).  The largest and oldest specimen we have is nicknamed "Morphy".  Morphy had just recently bloomed earlier in the year which was a major excitement as this species only blooms once every 4 or 5 years after reaching maturity.  The reason it takes so long to bloom is because the bloom itself can get up  ~7-10 feet tall at most.  The flower is so huge that when it blooms the whole plant is just the flower and root ball or corm.  This takes up a lot of energy, so the plant then goes into dormancy for a chunk of time before anything grows.


A photo of what the flower bloom would typically look like (left). The pot in which Morphy lives in (right).


Unfortunately Morphy was already way past prime when started working so I have no good photos of it.  We do have two other younger Amorphophallus titanum individuals but none are old enough to bloom.  'Snape', the next oldest A. titanum  leaf stalk got an infestation of aphids and had to be cut to the corm. ("Snape got wizard lice!" I can't resist making the reference!).


A (Catasetum spp) orchid male bloom.

I learned about a very cool type of orchid this week call a Catasetum.  This type of orchid is dioecious, meaning it has the male and female reproductive parts on separate flowers.  The male flower attracts male bees with its unique smell which the bee uses as pheromones to attract female bees.  Once in the flower, the bee will hit the trigger hairs on the flower and shoot a capsule containing the pollen cap and anthers onto the bee. The capsule itself has an attachment base that looks very similar to a house fly's labium and has a sticky resin that soon cements into a consistency not unlike hot glue. The force at which it attaches is surprisingly strong given how small the capsule is.  Once it is attached, the bee flees from the flower due to the force of the capsule being expelled.  Since the female flowers look completely different than the males the bee has a different association and will pollinate the flower.  Catasetum only produce female flowers when in optimal conditions and must be a large enough to handle going dormant in winter with seed capsules.


The pollen capsule and trigger hairs of a male Catasetum expansum flower.


The released pollen capsule and anther cover (left) and the pollen capsule without cover and showing the anthers (right). Photos taken by Terry.

Carnivorous Plants of Dartmouth College's Life Science Greenhouse:


Venus Flytrap (Dionaea muscipula, Family: Droseraceae).  This species is actually the only one in its genus and can easily be recognized by most. The 4 trigger hairs on the inside of the leaf-traps react when enough pressure is exerted, closing the leaves with surprising swiftness.  Despite the fact that they live in harsher environment like wetlands, they can be fairly finicky to care for and require distilled water to survive.  When raising carnivorous plants from young they need special attention so we relegate them to the Sick Orchid Room.


There is almost nothing quite as adorable as 'baby' Venus Flytraps when working in the Greenhouse.  This particular baby's leaf-traps are only about 4mm wide.  Watering at this size will be enough pressure to close the leaf-traps.  The adults are in winter dormancy now so they are not quite as photogenic as the younger ones.


Sundew flower stalk (Drosera spp, Family: Droseraceae) blooming in the Sick Orchid Room


Lance leafed sundew (Drosera adelae, Family: Droseraceae) in the Tropical Room.

While sundew are in the same family as Venus Flytraps, only the flower looks similar.  When a carnivorous plant flowers, they often will produce the flower stalk a good distance higher than the insect traps in order to prevent accidental consumption of pollinators.  I have always liked sundew (both the flowers and the leaves).  It is a very attractive plant for multiple reasons.  The leaves have little hair-like extensions that excrete sweet smelling sticky substance that attracts and then traps unwary insects.  The leaves then slowly fold around the captured 'prey' and digests it.  They are very hardy plants depending on the species. Some are found as far north as Newfoundland, Canada.


Two different types Pitcher Plants (Family: Sarraceniaceae): Sarracenia x wrigleyana 'Scarlet Belle' (left) and Heliamphora heterodoxa (right).

These are the typical types of pitcher plants we see around New England wetlands. These specific species are not found locally but they are very similar in morphology.  The 'pitcher' part of the plant is a modified leaf that has been fused partially to create a pool for insects to fall into and be digested by the enzymes within the plant.


Tropical Pitcher Plant (Nepenthes stenophylla) (I like to call them 'hanging pitcher plants'). This particular group of pitchers are epiphytes that live in the understory of Southeast Asian rainforests.  The pitcher section of the plant is actually an modified extension of the midvein of the leaf.  The lid is used to prevent runoff from collecting in the pitcher cup. When an insect is attracted by the sweet smelling rim, it will fall in and be trapped while digestive enzymes slowly consume it over time. The lid is also used to prevent any escape from the "prey" (I use that term very loosely).


Photo taken by Terry.

This internship has been wonderful.  I have really learned a lot and enjoyed myself.  Working and handling plants is a lot more messy and involved then many people expect first coming in, but I really like that aspect.  Sure you come home with your nails caked in soil or spend an afternoon taking out cacti spines from your hands with forceps but that's all part of the fun.  You can't really work with plants without getting messy.

I came to the internship with the hope to learn specific skills that will help me in future career paths.  They were to: Gain experience with the application of Integrated Pest Management; Learn techniques for caring for plants with narrow tolerance limits; Gain experience with combatting a variety of plant pathogens; Improve my skills with organization and professional development; Learn to identify a broad range of plant species.  I feel as though I was able to develop all those skills to an extent and should be able to apply them to my next steps where ever they may be.

I will definitely miss the Greenhouse and the people who work in it! This has been a really great internship and I would highly recommend it to anyone interested in botany or entomology.  You have to be willing to get dirty and be on pest-patrol.  But they really do welcome any amount of help.

On a more somber note, I just heard about the passing of the Unity student, John Fox. While I didn't personally know him that well, I want to send my sympathy and support to the Fox family and those at Unity.

Until Next Time!

Saturday, December 3, 2016

Unity College Dartmouth Greenhouse Week 5

Week 5: 11/21/16-11/23/16; ~17.3 hours left

While this week was a short week, a lot happened so it feels like it was longer.

Photo taken by my co-worker Terry

My older brother came to visit me while I worked this week so it was nice.  He actually came to get his orchid checked out by the Greenhouse workers.  It was a Dendrobium sp hybrid.  The orchid had not flowered in years and would only occasionally produce new growth.  My co-worker Terry helped diagnose its condition and requirements for flowering.  She is very knowledgeable about orchids as she is usually the one in charge of their upkeep.  What was determined was that the orchid needed to have a winter dormancy.  All the species that makes up the hybrid have to go through a dormancy period where you stop watering and fertilizing of the plant for the winter months.  The hope then is that the orchid would then bloom in the spring once the temperatures had warmed and the light had increased.  After this year's dormancy, the orchid should be repotted and a change of substrate.  As I may have mentioned before most if not all orchids are epiphytes (grow on other plants or surfaces that are not soil).  They do not live in soil so they require a substrate that has a certain level of aeration. When the substrate starts breakdown, it starts to choke the orchid.  This particular orchid hybrid was potted with coconut husk substrate.  Coconut substrate degrades faster than substrates like fur bark. Once the dormancy is over switching to fur bark would be best. Orchids also like to be pot-bound rather than 'over-potted' so it needs a smaller and taller pot.

According to my brother, the flowers look similar to these Dendrobium here in shape and size.

Mainly this week I finished clipping down the plants in the Tropical Room. The Yam vine ended up winding its way up past the sun screen and around the water pipes and the hydraulics in the door. It was like untangling rope but more difficult as the vines branched out every which way.

While using a ladder to clip can be dangerous, the fact that there were so many support structures around me allowed me to maintain my balance relatively easily while being in unusual positions.  To maintain those positions one must move slowly and incrementally, and be very aware of the pressure exerted on anything.  One cannot put too much pressure in one place.  I usually try and keep my pressure on the sides of structures, not fully downwards. And as always REMEMBER TO BREATHE!

Photo taken by my boss Kim

I had to trim back the philodendron in the Tropical Room (Philodendron erubescens). We have two types of philodendrons in the Greenhouse.  Both are very large and have a tendency to grow where ever they can get away with. Unlike vines, they don't tangle around themselves nor have modified leaves to grab with.  In order to climb, they use whorls of adventious roots (above-ground roots that are used for purposes other than absorbing nutrients) to grab at and support themselves as they grow.  In the case of our greenhouse, it means climbing the walls and structural supports of the Tropical Room.


In order to cut it down to size, I had to saw two of its stems off.  The stem itself was very fibrous and dense. It kind of reminded me of a combination of bamboo and rhubarb.


Each fresh leaf scar will produce a vibrant red and pink sap that beads profusely. It stained a little on skin so I could see it being used as a natural dye.


Recently most of the citrus plants have been producing fruits, so the Subtropical room has had a very pleasant smell this week. The Greenhouse has a lot of citrus species and hybrids; from Lemons to Sweet Limes to Kumquats and a couple of hybrids that I had not even heard of.  Some of the major producers in the Subtropical Room were the Lemons.  Most of the lemon varieties we have are not the lemons we typically think of; ie the "store-bought-lemon" (Citrus × limon; citrus hybrid).  They are sweeter than store lemons but still sourer than an orange.  I found out to my surprise that most of the edible citrus fruits that we think of are in fact a series of hybrids that were bred from other older species like the citron and the mandarin.  Unlike apples which are multiple varieties and subspecies of one original species; citrus fruits are hybrids on top of hybrids.

Meyer Lemon (Citrus × meyeri; citrus hybrid). It is roughly the same size as a store-bought lemon, maybe a little smaller.  The tree itself was fairly laden with them so my boss gave me some of the ripened fruit to me for Thanksgiving.  I was very touched by the gesture as they were grown from the Greenhouse.  The smell of the rind was very strong even before peeling.  The rind itself was thinner than a typical lemon but still harder to peel than an orange.  the flavor was much stronger than that of a grapefruit but still had a particular sweetness to it.  It was still very potent so I could only eat it one section at a given time. This made it very good in teas.

Pondarosa Lemon (Citrus limon × medica; citrus hybrid).  This fruit was huge, especially when it was compared to the size of the tree it was on (the tree was only at most ~3 feet, including the pot). Unlike with the Meyer Lemon the fruit took a long time to ripen or at the very least a long time to stay on the tree.  You can never be quite sure unless you pick it.


A banana 'tree' flower inflorescence (a group of tightly packed flowers like lilacs) (Musa acuminata).  The inflorescence does not flower all at the same time, the lower flowers bloom first and gradually bloom upward.  You can see the fruit starting to form at the base of the inflorescence.  This species of banana produces a dwarf version of the cultivated banana we are used to.  It is actually thought to be a precursor of that cultivar.

The Scarlet Ball Cactus (Parodia haselbergii) finally bloomed!  It had not bloomed since I started working here except for a few dead blooms that had not been removed.  I had removed the dead blooms before any new buds came in.  My hypothesis was that the dead blooms were preventing the cactus from creating fresh blooms and by removing them it allowed new blooms to come in.  Often if a plant has gone through its seeding stage and the seeds are allowed to stay on the plant, it will not have the need to flower as the next generation is "secure" so to speak.  If you remove the flowers before they seed, it triggers the plant to 'think' it is under stress and will produce more flowers as a response.

Have a good week! Happy Thanksgiving weekend!

Saturday, November 26, 2016

Unity College Dartmouth Greenhouse Week 4

Week 4: 11/14/16-11/18/16; ~43 hours left

Sorry I have been busy with thanks giving preps, so this blog post is late!

At the greenhouse we have multiple substrate and soil type based on the requirements of the plants, the substrates are usually used for the orchids and other epiphytes.  We have 3 major soil mix types: Metro Mix (for the general unspecific plants); Cactus Mix (for the xerophytes and plants that require high drainage); Tropical Mix (for the plants that are in the Tropical Room).

This week I got to learn how to mix up a new batch of the cactus mix soil, which I was very excited about. Since being put in charge of the Xeric Room (ie Cactus Room), I have done a lot of re-potting and dividing and so the cactus mix had become very depleted.  Each soil mix has their own particular recipe specific to the plants that are to be potted. Cacti need soil that is well drained and some what alkaline ('basic', ie acids and bases).
The bin that the cactus soil mix is held in.

To measure out the larger amounts of ingredients we usually use metal basins that each about half a bushel.  I first measured out "garden variety" potting soil mix (I made a pun there) as the base for the mix.  Then I added a decent amount of sand (I don't think that it matters what type of sand, just the size of the particles). The sand adds drainage to the soil and matches the natural soil type that cacti grow in.

The next two ingredients are used to help with the drainage allowing the roots to dry out
Perlite is a volcanic rock that is very similar to pumice but is a brilliant white. It is very chalky and dusty.  Turface is a gritty gravel like mineral that has a reddish coloration. According to my boss it has been used in athletic fields for drainage and traction (ie the reddish-brown areas of a baseball field).  I had to ware a face mask while handling the perilite and turface due to the dust they created.  By themselves the aren't particularly toxic or caustic, it is the actual inhalation of the dust they create that is harmful.  As a final additive we add a small amount of the pellet fertilizer, 10-10-10 and Calcium Carbonate (CaCO3) because cacti usually like the soil to be a little more alkaline.


Perlite (left) and Turface (right) I was unable to take pictures of the process itself as the dust would damage the camera.

When mixing up the soil I would use a metal dust pan to fold the layers together on the prep table in the prep room.  After mixing, I was able to re-pot some of the plant
It is very satisfying being able to not only re-pot plants your self but mix up your own soil as well.

This Wednesday was the last Botanical Illustration Class that was to be held during my stay as an Intern.  I had not known this earlier but Dartmouth College worked on a Trimester Schedule not a Semester schedule. The students classes ended this week and they would restart after New Years.  This also effects the other community events that the College offers during the semester.  I am somewhat familiar with the trimester method as my older brother got his bachelors degree at a college that had a similar set up.

During the class we mainly did a wrap up of what we had learned previously and the teaching artist's work.  Many of them were on local Vermont spring ephemerals such as ladyslipper orchids and crocuses.  We went on to discuss in detail the botany of the native ladyslippers.  One in particular I had not known about or realized was so local was the Yellow Ladyslipper or Cypripedium parviflorum (it was originally included with the species C. calceolus, which is a European species).  The specific epithet "calceolus" means "calcium rich" and refers to the fact that the orchid only grows in alkaline soils.  Local orchids are unique in their germination methods.  Unlike other seeds, orchid seeds have no extra nutrition added (ie no endosperm or pericarp). To germinate those seeds, mycorrhizal fungi are require to be present in soil.  This mutualistic relationship allows the orchid to gain enough nutrients from the fungi to grow.





We also were reminded to practice regularly even though there will be no more class.  That is the only way we will improve.  Everyone in the class was very kind and helpful allowing me to take part even though I am not an OSHER member or signed up for the class.  I hope to see them in the future outside of the class.


As with any greenhouse, we have to keep control of the growth of the plants so they do not strangle the other plants or the greenhouse itself.  Many of the plants in the different rooms ended up strangling and choking the equipment and pipes.  Since it got to the point where the climate controls for the rooms were getting effected, I was tasked to clip back those vines and plants so that they don't choke the greenhouse.  I worked mainly in the entry room, main hallway, tropical room and cacti room.  It was very difficult work as I had to use a ladder and many of the vines had gotten seriously tangled within each other and the greenhouse infrastructure.  The wax plants were probably one of the worst to work with as not only did they have a thick waxy cuticle and milky stick sap that is almost impossible to get off.  I make a specific point that there were enjoyable parts of this work as I was able to view parts of those plants that otherwise were hidden.


A Bougainvillea vine blossom tangled up in one of the misting pipes. There were a good amount of thorns on this plant so it was very tricky to remove.


Two views of the Bower Vine (Pandorea jasminoides), the vine itself (left) and a flower (right). Many of the vines had escaped up into the sun screens to get more direct sunlight.

Have a great break!

Friday, November 18, 2016

Unity College Dartmouth Greenhouse Week 3

Week 3: 11/7/16-11/10/16; ~86 hours left

This past week  has been tough for me to function with my typical enthusiasm and focus due to the election and  resulting aftermath.  I feel as though protecting the environment that we have left has just got much harder.

To distract from politics I have been focusing on tending to the basic needs of the plants (ie fertilizing, pruning, repotting) and the general upkeep of the greenhouse itself (ie clean drains, sweeping or squeegeeing the floors).  During the week I would often survey the different rooms to look for tasks that needed doing. I focused specifically on the Subtropical Room and the Cacti Room to trim and dead head the ferns and other 'leggy' plants or repot the xerophytes that were overgrow.


Rabbit's Foot Fern (
Davallia fejeensis) in the Sub-tropical Room, a large section of the subtropical plants are ferns and primitive plants (ie mosses, liverworts, clubmosses).

To keep track of the species we keep in the greenhouse we keep inventory lists. There are two separate lists one for the orchid and the general plant species. W
e have a large variety of orchids and most are housed separately.  The lists are organized by family and then species and includes their location, their potting information (ie size, re-potting dates, division dates, quantity).  Every time we re-pot or divide a plant we have to update their information in the inventory list. Normally this is done by hand on a printed copy that is then updated digitally.

The illustration class this past week was probably what helped me get through the day on Wednesday.  The lesson was to show the incremental steps involved with layering the watercolor to give the desired effect.  They also discussed the inclusion of fractals and Fibonacci's Sequence into botanical illustration and other precision based art forms.  They mentioned the NH artist, Maxfield Parrish as a prime example of precision and composition.  He apparently used surprisingly complex equations to create his art pieces whether they be murals or children's book illustrations.

A water lily called Blue Pigmy (Nymphaea colorata) that is native to eastern Africa. Its blooms only last one day so I was lucky to take pictures when I did!

A large percentage of the research done in the research section of the greenhouse is with transgenic rice.  Some of the professors are working on a way to prevent the ability of the rice to absorb heavy metals.  Accumulation of those metals lead to negative health effects.  To test the content of that rice, they have to harvest each generation of the rice seeds and pick the they want for the new generations.

In those experiments they must have a 'zero pest policy'. Any biological contaminations would potential change the outcomes.  The particular issue that the researchers had was with aphids attacking the young rice plants.  If the aphids are not removed completely they will prevent the rice seeds from forming.  This would halt the entire experiment as they need to be able to test those seeds.  To deal with this, we at the greenhouse use pesticides as a sterile environment must be maintained.


When using pesticides you are suppose to use multiple modes of action so as to not let the target species develop a resistance. Multiple modes of actions just refers to the different ways the chemicals are applied and/or effect the target.  One pesticide that was a possibility was Pyrethrum TR (aerosol spray).  It is derived from chrysanthemums.  For the chemical to work it must have physical contacted with the insect's cuticle.  I don't know the specifics but it effects the sodium channels in neurons, killing the insects.  Another pesticide with a different mode of action was Preclude. It is an insect growth regulator which means it prevents the insect from fully maturating to a sexually active adult.  This pesticide is not practical for dealing with aphids as it does not kill the young and aphids have a very flexible life cycle that allows them to reproduce at multiple stages.  The final type of pesticide we discussed was a systematic insecticide called Marathon II.  It is absorbed through the roots and transmitted throughout the plant.  When the insects feed on the plants it kills them.  The pesticides last for a couple weeks.

On Thursday, our order of bio-control species finally came in:


#1: Steinernema feltiae (Predatory Nematodes): These are the same nematodes that I used in the research lab to inoculate the mustard relative.  They requires lukewarm water to become active.


#2: Cryptolaemus montrouzieri ("Crypts"): They came as adult beetle. Hopefully they will mate and then lay their eggs on the plants with high populations of mealybugs.



#3&4: Predatory Mites- Neoseiulus californicus (left); Stratiolaelops scimitus (right): They will be let out on certain plants to consume the larval stages of the thrips and fungus gnat.

#5: Chrysopidae (Lacewing):  The eggs are attached to little paper sheets which will be hung on the plants.  The larvae which are voracious predators are supposed to hatch and then start consuming what ever pest species it can get its mandibles on.


#6: Eretmocerus spp. (Parasitic Wasp): This wasp could only be sent as a pupal stage rather then an egg as the larval stage is parasitic. They will parasitize aphids turning them into something like a mummy.  This lasts until the larva is ready to burrow out and begin metamorphosis, starting the process over again.

#7: Amblyseius cucumeris (Another Predatory Mite): I had to replace the old packets with the new ones on the plants in all the rooms except the Cold Orchid Room.  The temperature is to cold for them.  We can also compost the old bags without going through a complex process, which is nice.

Here are some pictures of the Welwichia (I know that some of you were asking for them). Unfortunately they do not show just how impressive the fronds are:




Have a great weekend!!