- The Fennel Bulbs were first referred to as "Family Trees" during a call with Mike Russo:
- Son, that's not a fennel, that's a family tree.
- Phrase taken from the (alleged) Voltaire quote, "Plant your family tree in the soil of the arts," which appears in the promotional video and accompanies the image of hands planting a fennel in dirt
- Further phone calls with members of the Milwaukee Tourism Commission, emphasize that "they belong underground"  
So I asked about other vegetable options and he said there were plenty, although if this was a roundabout way to ask about the "family trees", that they do NOT recommend eating them, as they belong underground. Also they are still exploring their sonic/psionic? capabilities. He said they're best left as they are, where they can function as defense mechanisms, although through a braintrust between Blackstar and MTC they're looking into using them as an alternative source of power for the city (since Go.D.S.E.E.D. failed to provide that).
- 1:25 - Worker plants a fennel bulb in the ground
- 1:38 - In the Jagoda Museum Center Activity Place, coloring pages with depictions of fennel are visible on the walls
- 2:45 - A fist punches a fennel bulb while the narrator says "Review"
- 2:50 - Worker places a fennel bulb under a bench while the narrator says "Under"
- 6:03 - The fennel bulb coloring pages are shown hanging out of a trash bag
- 9:58 - Treasure Hunter M is shown standing above glowing fennel bulbs, which may be buried in the ground
- 10:08 - The lyric "Charming yasai" (charming vegetable) may be a reference to fennel
- 10:10 - The lyric "Exquisite ankoku" (exquisite darkness) may refer to the fennel belonging underground
- 10:14 - The lyrics "The flax seed blossom / Its oils rich and milky" may refer to the role of the fennel as the flax seed (see "Blackstar no Blackstar" section)
- 0:17- Worker carries a briefcase with the fennel image also found on the coloring book page attached to its side
- 0:23- Basketball Kid raises a fennel bulb in the air, apparently causing Worker's glasses to break
- Found on a piece of paper located during the New York drop
- Children in the Jagoda Museum Center Activity Place, Milwaukee, are given printouts of fennels with the phrases "these belong underground" and "where are yours?" to colour in (a blank version of this is shown right).
- On Nov 21, 2008, IP address 184.108.40.206 edited the Wikipedia article about fennel, adding a section titled "Fennel in popular culture", with the text: "Featured prominently as the "Flax seed" in the Japanese anime "Blackstar no Blackstar". As it is unknown who wrote this edition, it is impossible to verify whether or not this information is canon.