The eukarya domain's organisms consist of cells containing a true nucleus that is enclosed in a double membrane. This nucleus contains the genetic information (DNA) of the cell that directs its membrane-bound organelles, which are also specific to the eukarya domain.
There are five supergroups within the eukarya domain, including archaeplastida. It contains green algae, green seaweeds, red seaweeds, and land plants. Naturally, one would think the plants would be in the same supergroup as fungi, but this is not true. The fungi are actually Opisthokonts. Key differences, including cellulose in cell walls and use of photosynthesis, separate the plants from the fungi.
The kingdom plantae includes the photosynthetic land plants. They have chloroplasts containing chlorophyll, as well as cell walls containing cellulose. They also store their photosynthetically-produced sugars as starch.
The tracheophyta phylum contains the vascular plants. These plants have tissues specialized for transporting water absorbed in the roots to the top of the plant (xylem) and photosynthetic products from the top of the plant to the bottom (phloem). This phylum includes the ferns, club mosses, angiosperms, and gymnosperms. The specialized tissues have allowed the plants to grow to larger sizes while still being able to nourish themselves. As plants reach larger sizes, diffusion is no longer enough for it to get what it needs. The sporophyte (diploid) generation also becomes the dominate generation, whereas the nonvascular plants usually have a dominant gametophyte (haploid) generation.
The plants that make up the magnoliopsida class are vascular and produce flowers at some point in their lifetime. This class is the largest class of land plants with over 250,000 species. This class is further divided into the eudicots and monocots.
This order contains eudicots included in the eurosids I lineage. These plants have unisexual flowers (only male or female parts on the flower) and are commonly pollinated by insects or wind. The eudicots also have two cotyledons, netlike veins in the leaves, and taproots.
This family, also well-known as the cucumber family, includes the plants that use their shoots or tendrils to wrap around other objects nearby for support. Yellow or white flowers are most common in this family and their stems are "hairy".
"Cucurbita" is the Latin word for "gourd". These plants contain fleshy fruits and are monoecious plants, meaning a single plant has both male and female flowers. They also tend to have a plethora of smooth, oval-shaped seeds.
Species: C. maxima
Cucurbita maxima, most commonly referred to as the pumpkin, is a monoecious, annual plant that grows to large sizes at a uniquely fast pace. The species got its name from the Latin word "maxima", which means "largest". On September 29, 2007, the world's largest pumpkin was recorded at 1,689 pounds!
The following phylogenetic tree shows C. maxima's lineage (with underlined names) from the eukarya domain to the plantae kingdom. The land plants have a close relationship with both red and green algae, included in the archaeplastida. This tree was based on morphological data.
This phylogenetic tree was also based on morphological data. It shows the lineage (with underlined names) of C. maxima from the core eudicots, which are a subclass within the magnoliophyta class, to its species. Its closest relatives are C. moschata and C. pepo.
Now that you know the pumpkin's closest relatives, I know you'll want to know more about its origin and habitat.