The Main Event of the Day: Sexual Encounters of the Floral Kind.

To fully understand the film, you need to recall:

SPORANGIUM - a multicellular structure in which spores are produced

SPORE - a haploid propagule produced via meiosis from a diploid reproductive cell

• MICROSPORE - a male spore; one that grows into a gametophyte bearing antheridia
• MEGASPORE - a female spore; one that grows into a gametophyte bearing archegonia

SPOROPHYLL - a leaf that bears sporangia

• MICROSPOROPHYLL - a sporophyll that produces male spores (microspores)
• MEGASPOROPHYLL - a sporophyll that produces female spores (megaspores)

Flowering plants, like the ones we saw on our tour of the arboretum on Monday, have all of the above, but they are highly derived with respect to their more primitive counterparts in the ferns and even the gymnosperms.

All the parts of the flower are modified leaves!

The microsporophylls of the flower are the STAMENS, consisting of the ANTHER and the FILAMENT.

The megasporophylls of the flower are the CARPELS, each consisting of an OVULARY (where the ovules develop), the STYLE, and the sticky STIGMA (which serves as a "landing pad" for the pollen.

The petals in animal-pollinated plants are usually showy and colorful. Collectively, they are called the COROLLA.

The sepals, the green modified leaves just outside the petals, are collectively called the CALYX.

The corolla plus the calyx are together called the PERIANTH.

Only Dicot flowers have a separate corolla and calyx. In Monocots, the two are not distinguishable, and so the whole thing is just called the Perianth, whether showy and colorful or tiny and green.

The job of the flower: SEX.

And now that you know that, let's have some

SEXUAL ENCOUNTERS OF THE FLORAL KIND.

HAPPY THANKSGIVING!