- Notothylas is a genus of hornworts classified in the division Bryophyta. It reproduces both sexually through spores and vegetatively through parts of the thallus. - The life cycle involves an alternation of generations between a thalloid gametophyte generation that produces gametes and a sporophyte generation that is bullet-shaped and produces spores. - Species of Notothylas are found worldwide in moist habitats and vary in characteristics of the thallus, sporophyte structure, and spore ornamentation. Rare species like N. yunannensis from China have unique traits that distinguish them from related species.

1. SEMINAR TOPIC : NOTOTHYLAS
Paper : Bot 104 MSc. Pre. 1st sem
SUBMITTED BY : PRIYANKA NAGAL
SUBMITTED TO : DR. SUNITA ARORA

2. NOTOTHYLAS
POINTS TO BE DISCUSSED :
• CLASSIFICATION
• GENERAL CHARACTERS
• REPRODUCTION
• LIFE CYCLE

3. CLASSIFICATION:
DIVISION : BRYOPHYTA
CLASS : ANTHOCEROTOPSIDA
ORDER : ANTHOCEROTALES
FAMILY : NOTOTHYLACEAE

4. GENERAL CHARACTERS:-
• Found in moist habitat.
• Notothylas shows strong resemblance with Anthoceros.
• The genus comprises a number of species which are widely
distributed both in the tropics and temperate zones.
• N. indica, N. levieri, N. chaudhurii and N. javanicus found in India.
• It is the smallest hornwort, grows few centimeter.
• It is also unusual among hornworts, its sporophyte is bullet shaped
and of few millimeters in length.

5. THALLUS
External Features:-
• Rosette like thallus
• Dorsiventral flat
• Thin, delicate, smooth
• Light yellowish
• Toothed or entire irregular processes
• Unicellular, smooth walled rhizoids
• Scales and tuberculate rhizoids are absent.
• On gametophyte, bullet shaped sporophytes arise at margins of thallu
• No midrib seen

6. Internal structure:-
• 6 to 8 layers of cell
• Stomata present on lower epidermis
• Mucilage cavities present at lower
region of thallus forming slime pore
opening.
• In N. javanicus mucilage cavity is
absent.

7. Reproduction:-
1.Vegetative
-Death and decay thallus part
-Bulbs
-Tubers
2. Sexual
-Production of meiospores.
-Monoecious are strongly protoandrous.

8. Development of
Antheridia:-
• Occur in clusters of 2-6
in antheridial chambers.
• Protoplast of each
androcyte form a single
biflagellate sperm.

9. Development of
Archegonia:-
• They are present
close to the
growing tip of the
thallus.
• 3-5 NCC wider
than Anthoceros.

10. Fertilization:-
• Oospore forms after
fertilization.
• Sporophytic generation
begins.

11. SPOROPHYTE:
• Sporophyte grows out horizontally from the fertile lobes usually in
pairs, its length about 3mm and 0.5mm in diameter.
• It totally dependent on gametophyte.
• The first division in either transverse or vertical in zygote after
fertilization.
• In N. indica and N. levieri the sporogonium is completely enclosed
within the involucre but N. javanicus and N. breutelii it slightly
projected beyond it.
• Supporter columella varies from species to species.
• The pseudoelaters are simple, equal in size and longer than the
spores, with spiral and obique bands.

12. Columellate sporogonium:
• Entire endothecium forms the columella.
• Amphithecium cells divide into inner and
outer.
• N. indica
• N. orbicularis
Non-columellate sporogonium:
• Entire endothecium is fertile and forms
archesporium.
• N. choudhurii
Intermediate species:
• N. breutelii
• N. javanicus

13. DEVELOPMENT:
• Capsule wall is 3-4 layered thick
and lacks stomata.
• Sporogenous tissues around
columella.
• Sporogenous mass in mature
one is differentiated into
unicellular sterile cells and SMC.
• SMC undergo meiosis to form
spore tetrads with exospore and
endospore.

14. spore germination:
• Under favorable conditions the
spore absorbs moisture and
germinates.
• Exospore ruptures and
contents bulged out by small
papilla.
• Minute thallus form by first
transverse and second in
opposite direction with
repeated cell division.

15. Life cycle:

16. Rare and peculiar hornworts:
• N. yunannensis firstly reported in china- Yunnan, Thailand by T. Peng and R.L.
Zhu in 2012 and this was accepted in 2014.
• Its IUCN status is “Data Deficient” because of being small and ephermerial
characters.
• Its thalli is deep green, fascicular rosette, 7-15mm in diameter.
• 1) the irregularly arranged, sub quadrate to sub rectangular epidermal cells
the capsule,
• 2) the absence of the special dehiscence lines of thick-walled cells.
• 3) the vermiculate ornamentation of the spores radiating from a central hollow
on each proximal surface (Peng and Zhu, 2014).
• Notothylas yunannensis is closely related to Notothylas depressispora J. Haseg.
Haseg. and N. irregularis Chantanaorr., which also has vermiculate spores with a
small depression on each proximal facet.

17. References:-
• “Botany for degree students Bryophyta” B.R. VASHISHTA, DR. A.K.
SINHA, DR. ADAERSH KUMAR by S. Chand publications.
• Rare and peculiar hornworts: Notothylas orbicularis and N. javanica
(Notothyladaceae), new genus and species records for Australia.
• Phytotaxa 275 (1): 001–013 http://www.mapress.com/j/pt/ 2016
• Note on Notothylas yunannensis (Notothyladaceae,
Anthocerotophyta), a little known species of hornwort, Sirikanda
Rattanamanee and Sahut Chantanaorrapint*, Department of Biology,
Faculty of Science, Prince of Songkla University, Hat Yai, Songkhla,
90112 Thailand.
• Received: 9 February 2015; Accepted:18 March 2015.

18. Thank you