Collenchyma cells <unk> Collenchyma cells are alive at maturity and have thickened cellulosic cell walls. These cells mature from meristem derivatives that initially resemble parenchyma, but differences quickly become apparent. Plastids do not develop, and the secretory apparatus (ER and Golgi) proliferates to secrete additional primary wall. The wall is most commonly thickest at the corners, where three or more cells come in contact, and thinnest where only two cells come in contact, though other arrangements of the wall thickening are possible. Peinct and hemicellulose are the dominant constituents of collenchyma cell walls of dicotyled angionosperms, which contain as little as 20% of cellulose in collagenasites. Petenchyma cells are typically elongated and may confer meristem derivatives that initially resemble parenchyma, but differences quickly become apparent. Plastids do not develop, and the secretory apparatus (ER and Golgi) proliferates to secrete additional primary wall. The wall is most commonly thickest at the
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