Flera is a genetically engineered plant derived from lettuce. The original developers were rabbit provolves who lived on space habitats (historians can confirm that the design originated in the Watership Cluster, but exactly which hab is unclear).
The purpose of flera is to provide calorie-rich, nutritionally balanced food of sufficient bulk for a single serving to be filling. This maximizes the value of a given volume of food. One serving of flera contains all of the calories and nutrients that the subject needs for one day — as long as the eater partakes of the correct variant. There are dozens of subspecies of flera, each of which is optimized to meet the needs of a class of related bionts.
Flera is a common and popular food among sapient herbivores, especially the Lepusan man/rabbit splice, and many omnivores enjoy the occasional salad made with flera.
Bacca - Text by Anders Sandberg Family of crops derived from the tobacco plant through gengineering during the Solsys Era and later. Designed for use in space hydroponics, different strains produce livestock feed, vegetables, drugs and decorative flowers. Especially common is Qianxuesen, a bacca vegetable eaten, generally either boiled or mashed, by terragen bionts.
Endurasoy - Text by M. Alan Kazlev after original by Kevin Self Interplanetary age gengineered edible grain. A genetic blend of baseline soy and Cis-Lunar neogen plants, endurasoy is high in protein, fiber, and vitamins, and resistant to almost all known diseases and pests. Although its robustness makes it indispensable as a high yield plant, it can disrupt ecosystems on low and medium tech biospheres if not kept in check.
Slide - Text by John B Utterly tasteless and transparent foodstuff. It also has effectively no coefficient of friction, and may be infused with most any flavor. Favored as a texture by several clades, and sold in sealed single-swallow capsules, it's often held in the mouth until the taste overwhelms the taste buds then swallowed. Also very useful in sabotage.