Abstract: There is provided a liquid discharge apparatus including: a reservoir configured to store a liquid; a head in which a nozzle is opened; a liquid circulator including a negative pressure pump, the liquid circulator being configured to circulate the liquid between the reservoir and the nozzle; a negative pressure regulating valve configured to regulate communication between a gas layer of the reservoir and an atmosphere; and a controller configured to perform: obtaining a nozzle pressure in an area, of the liquid circulator, near the nozzle; and controlling the negative pressure regulating valve to open, in response to the nozzle pressure being less than a first threshold value that is a negative value and greater than a second threshold value that is less than the first threshold value.

Abstract: There is provided a liquid cartridge including a casing which has front and lower surfaces, a storage chamber, and a supply port. A groove is arranged on the lower surface of the casing. The groove has left and right surfaces and an entrance port. At least one of the right and left surfaces has first and second surfaces. The first surface is directed in one orientation of the front-rear direction and in one orientation of the left-right direction. The second surface is positioned in the other orientation of the front-rear direction as compared with the first surface and is directed in the other orientation of the front-rear direction and in the one orientation of the left-right direction. The groove is configured such that a latch enters the groove.