iambic pentameter
This line is in iambic pentameter because it has ten syllables that alternate unstressed then stressed.
u / u / u / u / u /
To | swell | the | gourd,| and | plump | the | ha | zel | shells
1 2 3 4 5 6 7 8 9 10
When trying to identify meter and rhythm, start with two syllable words-this will help identify where some stresses sit in the line.