The other main bladder type is characterized by the door only being raised to an 45° angel or lesser with the threshold. This type is present in most epiphytes, lithophytes and swamp plants, which in general have small bladders often only one mm large or lesser. In general, the vestibule is relatively long and tube-like such as in Utricularia reniformis (right photo). The antennas are unbranched and bent towards the bladder as it may appear from the picture to the left of a nearly mature bladder. The whole plant is densely covered with slime-glands, which together with the antennas are of importance for maintaining a water film around the bladder. This seems important when the plant is growing as an epiphyte in a moss cushion.