This document provides information on the systematic position, morphology, anatomy, reproduction, and life cycle of Lycopodium. It discusses that Lycopodium has 400 species found in varied habitats worldwide, including in India. It has dichotomously branched stems and leaves without ligules. Reproduction occurs vegetatively and via spores. Spores form in structures called strobili and develop into homothallic gametophytes that produce both antheridia and archegonia for sexual reproduction. The life cycle involves a diploid sporophyte and haploid gametophyte generation.

1. Structure, reproduction, life history and
systematic position of Lycopodium
Sankrita Gaonkar
Assistant Professor in Botany
sankrita002@gmail.com

2. Contents
• Systematic position
• Morphology
• Anatomy
• Reproduction
• Life cycle
• References

3. Systematic position
• Division – Lycophyta
• Class – Lycopsida (Eligulopsida)
• Order – Lycopodiales
• Family – Lycopodiadeae
• Genus - Lycopodium

4. Lycopodium
Distribution
• 400 spp. – found under varied habitats
• Some grow in cold climates of Arctic region
• Some inhabit tropical and sub-tropical regions
• In India – 33 spp. – mostly in Eastern Himalayas, South
Indian mountains
Habit
• Most are tropical spp., epiphytic – grow hanging from tree
trunks
• Temperate spp. – grow in wood-lands, on moist and acidic
soils
• Short creeping stems with erect strobilus bearing branches

5. Stem:
• Dichotomously branched
• Dichotomy – equal or unequal
• Unequal branches – one remains small and other grows
longer
• Small branches ultimately stop growth and bear strobili
• Unequal dichotomy  Pseudomonopodial – e.g., L.
clavatum, L. densum, L. obscurum
Leaf:
• Simple, sessile, small, have single median vein – microphylls
• In some, leaves are scaly
• Eligulate
• Spirally arranged
• Isophyllous or anisophyllous

6. Root:
• Dichotomously branched
• Arise from lower side of prostrate stems

7. Anatomy
Stem:
• Epidermis – single layer – cutinized, stomata
present
• Cortex – 1) thin walled (intercellular spaces),
2) sclerenchymatous cells (no intercellular
spaces), 3) 3 zones – outer thick walled,
middle large and thin walled cells, inner thick
walled cells
• Pericycle – one or many layered
• Vascular region – protostele, actinostele (L.
selago), plectostele (L. clavatum), mixed
protostele (L. cernuum)

8. Leaf:
• Epidermis – single layer, cutinized, stomata
• Mesophyll – loosely arranged chlorophyllose cells
• Vascular region – single vascular strand, mesarch

9. Root:
• Epidermis – single layer, thin walled, root hairs
• Cortex – outer thick walled, inner parenchymatous
• Stele – polyarchy – many xylem and phloem bundles

10. REPRODUCTION:
• By vegetative means and by spores and sexually
1. Vegetative Reproduction:
(a) By Gemmae or Bulbils – modified vegetative structures – arise as lateral outgrowths
near stem apex.
(b) Fragmentation – branches gets separated from parent plant due to dead and decay of
older parts – grow into new individual plants.
(c) By Resting Buds – In some species, tip of the rhizome or branches store food material
and becomes thick with crowded leaves - resting buds. During unfavorable condition,
whole plant dies except resting buds – resumes growth at advent of favorable
condition, and produces a new individual.
(d) By Root Tubercles – originate from parenchymatous region of cortex. It consists of a
group of cells with stored food material and protected by thick walls – capable to
germinate into a new plant individual.
(e) By Adventitious Buds – developed from isolated bulbil leaves. It also develops in stem
near the apex

12. 2. Spore Formation:
• Spores formed in specialized reproductive structure – strobili (singular :
Strobilus) or cone
• Strobilus – slender, sessile or stalked, simple, un-branched or dichotomously
branched, arising at apex of stem or branches, consists of central axis in
which fertile leaves or sporophylls are spirally arranged. Each sporophyll
bears a sporangium at base
• Sporangium – yellow or orange with sterile jacket layer of 2-3 layers of cells
thick. Within jacket layer is fertile sporogenous tissue with nutritive tissue
known as tapetum. Sporogenous tissue later differentiates into spore mother
cells, each of which by meiotic division produces spore-tetrad
• Lycopodium is homosporous, i.e., it produces only one type of spores. As
soon as the spores are developed, haploid (n) gametophytic generation begins

14. Prothallus is homothallic – bears both male and female sex organs, i.e., antheridia
and archegonia in single gametophytic plant body
1. Antheridia – arise in several numbers in gametophytic plant body. They
remain either wholly embedded in gametophytic tissue or projected slightly.
Each antheridium is surrounded by a jacket layer of one-celled in thickness.
Inside jacket layer lies numerous sperm mother cells, which directly
metamorphosed into small, cubical, biflagellate sperm.
2. Archegonia – arise in numbers in gametophytic plant body . They also
remain sunken with only their neck projecting outwardly. A mature
archegonium consists of a neck, composed of 6-13 neck canal cells, and a
narrow venter, composed of one ventral canal cell and an egg cell.

17. References
• Vashishta BR. 2010. Botany for degree students:
Pteridophytes. S. Chand & company ltd.
• Pandey B.P. (2009). Botany for degree students: B.Sc. First
Year. S. Chand & Company Ltd. New Delhi.