7. Funaria : External morphology and internal structure of axis

Funaria: External morphology and internal structure of axis

1. Funaria : External morphology and internal structure of axis Dhole N. A. Department of Botany, Digambarrao Bindu ACS College, Bhokar

2. Classification of Funaria : Division : Bryophyta Class : Bryopsida Subclass : Bryidae Order : Funariales Family : Funariaceae Type : Funaria

3. 1. Plant body is gametophytic , and each gametophore consists of rhizoids, ‘stem’ and ‘leaves’ . 2. Each gametophore is slender, erect and attains a height of 1 to 3 cm or more . 3. Rhizoids arise from the base of the ‘stem’ in the form of tufts. 4. Each rhizoid is branched, filamentous, multicellular and contains oblique septa. 5. Rhizoids are colourless when young but at maturity they become brown coloured . 6. Rhizoids, if present on exposed axis, develop chlorophyll.

4. Ref. https ://www.biologydiscussion.com/wp-content/uploads/2016/09/image-554.png

5. 7. Function of rhizoids are absorption and fixation. 8. ‘Stem’ or axis is slender, erect, branched or unbranched and covered by the ‘leaves.’ 9. Apical tufts of ‘leaves’ are arranged on the ‘axis’ spirally in 3/8 type of phyllotaxy . 10. Each leaf is sessile, ovate with entire margin and acute apex. Each leaf contains a midrib. 11. In a mature gametophore, the lower few leaves are small, membranous and called scaly leaves; middle bigger, green leaves are called foliage leaves; and uppermost compactly arranged leaves are called perichaetial leaves.

6. https://www.biologydiscussion.com/wp-content/uploads/2016/09/clip_image004-44.jpg

7. The adult gametophyte (gametophore) is differentiated into rhizoids, axis or  ‘stem’  and  ‘leaves ’ . Rhizoids arise from the base of the axis. They are slender, branched, and multicellular and have oblique septa. Axis is 1-3 cm. high, upright, slender and branched. Each branch is extra axillary i.e., arise below a leaf. Leaves are sessile, oblong-ovate with entire margin, pointed apex and are arranged spirally on the branches and ‘stem ’. Each ‘leaf’ is traversed by a single mid rib. ‘Leaves’ are borne in 1/3 phyllotaxy which becomes 3/8 at maturity.

8. Internal Structure: 1. Axis or  ‘stem’ The transverse section (T. S.) of axis can be differentiated into three distinct regions: ( i ) Epidermis (ii) Cortex (iii) Central conducting strand or central cylinder.

9. ( i ) Epidermis: It is the outer most single layered protective covering consisting of small tangentially elongated chlorophyll bearing cells. Cuticle and stomata are absent.

10. (ii) Cortex : It is present between the epidermis and conducting tissue. It is made up to parenchymatous cells . Younger part of the cortex contains chloroplasts but in the older part they are lacking. At maturity few outer layers of cortex become thick walled and are reddish brown in colour but those of the inner layers become thin walled . (iii) Central Conducting Strand: It is made up of long, narrow thin walled dead cells which lack protoplasm. These cells are now commonly called as hydroids. Conducting strand besides providing a certain amount of mechanical support, functions in the upward conduction of water and solutes.

11. 2. Leaf : Transverse section (T. S.) of  ‘leaf’  shows a well-defined midrib with two lateral wings. Except the midrib region, the  ‘leaf’  is composed of single layer of parenchymatous polygonal cells. The cells contain many large and prominent chloroplasts. The central part of the mid rib has narrow conducting strand of thick walled cells which help in conduction.

12. References : https:// www.biologydiscussion.com/bryophyta/features-of-funaria-with-diagram-bryophyta/54320 https:// www.biologydiscussion.com/botany/bryophytes/life-cycle-of-funaria-with-diagram-bryopsida/53931

13. Thank you