The rachis is always the main stem of any flower cluster, seed cluster, frond, or compound leaf. The leaves of the marijuana plant are considered compound leaves and held together via rachises. Rachises can sometimes get a little stretched and look like little petioles (the stalk that attaches a leaf to the plant stem).

The world rachis is derived from the New Latin word ‘rhakhis’ which translates into ridge or spine. The term rachis is also used to refer directly to the shaft of a feather.

The heads of wheat are commonly held together on the stem with rachis stems. On wheat, the rachises are often referred to as ‘brittle rachises’ because as the wheat head dries, the slightest touch or breeze will shatter the rachises and disperse the seeds.

Rachis is also sometimes used in reference to the vertebrates that encase the spinal column because it forms the supporting structure of the physical frame and is the location where the other key parts of the body such as the head, shoulders, hips, and ribs attach.