from Wiktionary, Creative Commons Attribution/Share-Alike License
- adj. Having two little bags, sacs, or pouches
- n. Such an organism
from the GNU version of the Collaborative International Dictionary of English
- adj. Having two little bags, sacs, or pouches.
from The Century Dictionary and Cyclopedia
- Having two little bags or pouches attached: used especially in botany.
bi- + saccate (Wiktionary)
The four large pollen grains in your picture are so called bisaccate pollen which are produced by pine and fer trees.