Variabur

Variaburs are offensive plants that summon spiky roots from the ground to attack zombies, but it does not focus on the zombies.

Overview
One Variabur covers a lot of area. In the space it can reach, it shoots up a thorny root from under a random tile in the space. These roots deal 4 damage points, and they stay up for 0.75 of a second. Once it goes down, Variabur attacks again in another random spot. It is possible that Variabur will attack in the same spot twice.

A root will not spring up in a shallow (planks) or watery place. They can, however, appear under plants, though the plant will not be hurt. The roots of two different Variaburs will not show up in the same spot, meaning that a full column of Variaburs will have a somewhat consistent damage zone.

Variabur is slightly based on the burs found in the Arctium genus, though it is really based on burs in general. Its name is a portmanteau of "variable" and "bur."

Plant Food Ability
Using Plant Food on a Variabur causes it to attack in every tile it can at once. This attack deals 5 damage points every 1 second, for 6 seconds.

Strategies
A Variabur's range is most effectively utilized when it is on the center row (left to right). If you already have a Variabur there, plant in the rows above and below it. Only plant in the top or bottom row once the other rows have been filled up.

Variabur goes well with Spikeweed/rock. Variabur does not work well in Pirate Seas or Big Wave Beach, as they both have multiple spaces where Variabur cannot attack.

Trivia

 * Variabur's almanac entry references the historic duel between Aaron Burr and Alexander Hamilton.