1,194. Aravah-Like Species

Hilchos Shofar, Succah v’Lulav 7:4

There’s a species that resembles the willow but its leaf is rounder, its edges are serrated and its stems are not red. This species is not fit for use in the mitzvah. Another species of willow has leaves whose edges are smooth but they are also not serrated like a saw. Rather, it has tiny grooves resembling the edge of small sickles. This species is fit for use. All the identifications of the four species were transmitted via the oral tradition that was given to Moshe.

Hilchos Shofar, Succah v’Lulav 7:5

Taking the four species is one mitzvah; each one of them is necessary. Collectively, they are referred to as the mitzvah of lulav. One may not add to or detract from these species. If one of these species is not available, a comparable species can not be substituted for it.