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!

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!