1,207. The Growth of a Lulav's Spine and Leaves
Hilchos Shofar, Succah v’Lulav 8:3
If a lulav’s tip is severed, it is invalid. If a lulav is split so much that it looks like two lulavs, it is invalid. If a lulav is bent forward so much that its spine looks like a hunchback, it is invalid. If it is bent backwards, it is valid because that is its natural growth. If it is bent to either side, it is invalid. If the leaves have separated from one another but they haven’t started to droop like the top of a date palm, the lulav is valid. Once the leaves have burst apart so that they droop from the spine like the top of a date palm, it is invalid.
Hilchos Shofar, Succah v’Lulav 8:4
The natural growth of lulav leaves is for them to grow in pairs connected in the back. The back of each pair of connected leaves is called a tiyomes. If a tiyomes is split, it is invalid. If a lulav's leaves grow individually from the outset without ever having a tiyomes, it is invalid. If a lulav's leaves do not grow one on top of the other as lulavim do, but rather they grow one below the other, then if the top of a lower leaf reaches the bottom of the one above it, covering the entire spine of the lulav with leaves, it is valid. If the top of the lower leaf doesn’t reach the bottom of the one above it, it is invalid.