Complex Tissue Xylem

The chief water conducting elements of xylem in gymnosperms are:

Gymnosperms are also called softwood spermatophytes because they lack:

1. Cambium

2. Phloem fibres

3. Thick-walled tracheids

4. Xylem fibres

The balloon-shaped structures called tyloses:

1. originate in the lumen of vessels

2. characterise the sapwood

3. are extensions of xylem parenchyma cells into vessels

4. are linked to the ascent of sap through xylem vessels