Related על סוכה 1:11

One who makes his sukkah in the shape of a cone, or leans it against a wall, it is not valid. But R. Eliezer agrees that if it be placed on a roof with a space of a handbreadth s width, or if it be higher than the ground by a handbreadth, it is kosher.

Matting made of shavings or of large reed-grass can be used as a covering, but if it is small they cannot cover with it. Reed mats or rush mats, if large, may be used as a covering, but not they are woven toegther. But R. Yishmael b. R. Yosi said in the name of his father that even if woven together they may be used; and so R. Dosa says, following his opinion.

If one makes his sukkah as a shed [i.e. Indian tent] or that he supported it on a wall, it is disqualified. But R. Eliezer agrees [with the sages] in this, that if their roof has an opening of a handbreadth or if it above the ground even a handbreadth high [perpendicular] runs, is qualified. With a mat of dry reeds or of papyrus, if it is a large one, one may cover with it, and if it is a small one, one may not; and with one made of Haifa grass, if it is large, it may be covered, and if it is braided, one may not cover with it. R. Ischmäel son of R. Jose says on behalf of his father: even a plaited one, one may cover with it, and R. Dosa said it according to his words.