Question

Distinguish between male and female cones of pinus and cycas

Answer 1

Cycas:

1. A small palm-like tree.

2. Plant body differentiated into root, stem and leaves; the roots are of two types- normal and coralloid.

3. In the beginning the stem is tuberous, later on becomes columnar, un-branched and covered with persistent leaf bases.

4. Leaves large and compound with circinate vernation; leaf crown on the top of the plant.

5. Xylem consists of tracheids; companion cells absent from phloem; secondary xylem tracheids do not possess spiral thickenings.

6. No resin canals; mucilage canals present in the mesophyll tissue.

ADVERTISEMENTS:

7. Root stele diarch to tetrarch.

8. Girdle traces present in the cortex of stem.

9. During secondary growth several successive rings of cambium are formed; the primary cambium is short lived; secondary cambium rings form concentric zones of xylem; no annual rings.

10. Mesophyll tissue differentiated into palisade and spongy tissue; no peg-like infolding’s; xylem mesarch in the midrib.

Pinus:

1. A tall, branched tree.

2. Plant body differentiated into root, stem and leaves; tap roots and mycorrhizic roots.

3. Stem cylindrical, branched; the branches are of two types, i. e, branches of limited growth (dwarf shots) and branches of unlimited growth (long shoots).

4. Leaves needle-like and grow on dwarf shoots; no circinate vernation.

5. As in Cycas.

6. Resin canals present; no mucilage canals.

7. Root stele diarch to hexarch.

8. Girdle traces absent.

9. Secondary growth; the cambium ring is persistent and produces a continuous cylinder of secondary xylem; annual rings are formed.

10. Mesophyll not differentiated into palisade and spongy tissue; mesophyll cells have peg-like infoldings; two vascular bundles with endarch xylem.