Notothylas by p.n

Bryophyta genera: Notothylas

1. SEMINAR TOPIC : NOTOTHYLAS Paper : Bot 104 MSc. Pre. 1st sem SUBMITTED BY : PRIYANKA NAGAL SUBMITTED TO : DR. SUNITA ARORA S E M I N A R T O P I C : N O T O

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 thallus. 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 the 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 of 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. 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