Author: thelms

A new set of leaves is beginning to sprout! While I’ve run out of time to document any potential production of beans, I’m optimistic that they will appear eventually. This will be the summer of beans. I don’t even know what species of bean this plant is, which is all the more exciting! My plan is to move the plant outside during finals week– hopefully it will be consistently warm by then and the planting of the bean can serve as a celebration of the end of the semester. The end is in sight (but not for my lovely, persistent baby plant).

While growing at a slower rate than in its first week, the bean plant continues to thrive. Because this plant got a late start at things, it has not produced flowers or fruit yet. As a mature plant, it is now in its sporophyte generation, illustrated in the diagram below. If it ends up flowering, meiosis will produce microspores and megaspores, and male and female gametophytes, after which it will be able to reproduce (figure 2). I’m hoping that eventually I will be able to move the plant outside and see it produce beans!

I’ve given the bean a knitting needle for support. It’s not an ideal length, but hopefully it will give it a little something to climb on.

The leaves of the bean plant are growing! The larger leaves seem to be weighing down the stem, causing it to bend, so it may be time to add a support system for the plant to lean on or wrap around. The soil it is potted in seems to stay relatively moist for long durations, so I’m not too concerned about lack of water or turgor pressure. I think it may just need a boost! Below is a diagram illustrating the movement of water and nutrients through the plant. This week, my roommate and I planted some seeds in preparation for our garden this summer, so I will have these to keep an eye on as well.

I’m wondering if the flowering organs of the plant will be visible soon. For now, these enlarging leaves will hopefully be photosynthesizing enough to store abundant energy to produce healthy reproductive structures.

The bean plant is gaining height and bending toward the sunniest spot of the window. This is an example of phototropism, a hormonal response to light that alters the direction of plant growth. Under this process, auxin in the apical meristem builds on the shadier side of the stem, causing cells to expand and the plant to bend in the opposite direction, towards the light.

A closer image of the plant displays the leaves, including their opposite arrangement and netted venation. From this perspective, the underside of the leaf, the lower epidermis, is visible. Between this layer and the upper epidermis are the spongy and palisade mesophyll, which contain the chloroplasts. The final top layer is the waxy cuticle, which functions in reducing water loss from the leaf.

Woah! I am flabbergasted at the rate at which the bean plant is growing. It has amassed so much height and now has two full, true leaves a good distance above the cotyledon. These leaves are produced by axillary buds, and the terminal bud is visible between them. This is where auxin is produced, a hormone that induces growth via cell division, as well as inhibiting the growth of lateral buds lower on the stem.

The terminal bud also houses the shoot apical meristem, where undifferentiated cells undergo mitosis, increasing the shoot’s height. The apical meristem gives rise to three primary meristems, the protoderm, ground meristem, and procambium, which produce the epidermis, ground tissue, and vascular tissue, respectively.

Secondary growth, which increases the width of the stem, is induced by the lateral meristems: cork cambium and vascular cambium. The structures involved in secondary growth, including the vascular system, are diagramed below.

After only two days, the seedling has shot up and leaves are emerging! I’m thinking that something did indeed go wrong with my first seed, because the rate at which this one is growing is impressive in comparison. Hopefully, I will be able to observe this plant all the way to its flowering stage. Now that spring weather is around the corner, temperature and sunlight should be on the side of the seedling.

My new bean seed has taken to sprouting much faster than the first one. After just a few days, it is already poking out of the soil and looks a little bigger than its predecessor. I’m optimistic!

I have returned to find the bean in bad shape. I think it has passed the point of no return. This is a bummer. I shall try again with a new bean next week after lab! My suspicion is that things were just too cold as the seed was germinating and it wasn’t able to solidify its roots enough to make it through the current cold spell. Hopefully, things will start warming up and the next seed will have a better shot of making it to spring.

I’ve moved the seedling to the windowsill in my bedroom because I think it will get more light here. Initially, I was concerned about things getting too cold here, but my entire apartment is cold all of the time, so I don’t think it’ll make much difference. Plus, this frees up some space on my kitchen counter.

After a week, I returned the seedling to the kitchen before traveling to New Hampshire for a conference. I’ll only be gone a few days, but the heat will be off and I don’t want it to catch the drafts from the window, especially during the snowstorm that’s expected this week. Fingers crossed it can brave a few days on its own.

The seedling doesn’t seem to be developing much in the way of height or leaves, but it still has a bright, fresh, green hue to it.

This week, real actual leaves have appeared on the bean plant! The seedling is now sourcing its energy entirely from photosynthesis, rather than relying on food stores within the seed.

In Figure 2, the terminal bud is visible at the tip of the shoot, from which the seedling will continue to grow in height. The weather has been cold, but the bean seems to be getting plenty of sunlight.