In the script, the Two Lands were as a rule identified by the flowering sedge and papyrus. One can make a distinction between two types of use: simple (either papyrus or flowering sedge alone) or combined (both plants together). The simple uses may serve to indicate the origin of a substance or species, like the following:

A very early example of this use has already been mentioned in section 16: the use on earthenware pots from the 1st dynasty, referring to "taxes of Upper Egypt" and "taxes of Lower Egypt".

 Another use deals with the scope of an office. Some examples:

Surprisingly enough, some of these titles actually refer to the “king of Lower Egypt”. These are false archaisms - false, because there never was a “king of Lower Egypt”.

Flowering sedge and papyrus could also be used combined. This produced statements of a more emphatic nature: designed to stress totality, or completeness.
The following example comes from a relief showing the Sed-festival in Niuserre’s sun temple at Abu Gorab (5^th dynasty). Here, a group of magnates in attendance is described as:

(Reproduced in Schäfer, page 232).

The Great Ones of Upper and Lower Egypt. Or in other words: the Great Ones of all of Egypt.

In the temple of Luxor, the god Amun at some point says to Amenhotep III:

(DZA 30.098.240)

I give to you Upper Egypt (“the land of the sedge”), and Lower Egypt (“the land of papyrus”). In other words: “I give to you all of Egypt”.

On one of the colossi of Memnon, Amenhotep III uses the following Nebty-name:

(DZA 30.099.150).

Two Ladies: Great in monuments that extend his power,
spreading it from “Heliopolis of Lower Egypt” to “Heliopolis of Upper Egypt”.

The first one is Heliopolis proper, the second is a circumscription of Thebes. Although there is a lot of Egyptian ground north of Heliopolis, and south of Thebes, this expression should no doubt be understood as “spreading it over all of Egypt”.