Retort cells are present in Sphagnum, specialized dead hyaline cells in the stem cortex with elongated necks and terminal pores that enhance water retention and capillary action, aiding its bog habitat adaptation. The correct answer is option (1).

Option Analysis

• (1) Sphagnum: Correct; these flask-shaped (retort-like) cells occur in the cortical layer of the stem/branches, more inflated than surrounding hyaline cells, with a curved neck opening outward for water storage and inhabited by microfauna.

• (2) Riccia: Incorrect; thalloid liverwort lacks retort cells, featuring air chambers, rhizoids, and scales for anchorage/water conduction instead.

• (3) Funaria: Incorrect; moss with upright gametophytes lacks retort cells; its stem has parenchyma cortex and central strand, not specialized hyaline retorts.

• (4) Lycopodium: Incorrect; vascular pteridophyte (clubmoss) has xylem/phloem in stele, chlorophyllous cortex, but no retort cells—its water conduction is via tracheids.

Retort cells present in Sphagnum define this peat moss’s exceptional hydroscopic ability, appearing in the enlarged cortical layer as dead cells with necks resembling chemical retorts for capillary water uptake.

Structure and Function

In Sphagnum stems/branches, the outer cortex holds retort cells amid hyaline cells; each has a thick wall, spiral thickenings, and apical pore, absorbing/storing water (up to 20x dry weight). Absent in gametophytes of Riccia (thalloid), Funaria (parenchymatous), or Lycopodium (xylem-based).

Plant Comparison