An Overview of Peatland Bryophytes. Dale H. Vitt Department of Plant Biology Southern Illinois University Carbondale, IL

Transcription

1 An Overview of Peatland Bryophytes Dale H. Vitt Department of Plant Biology Southern Illinois University Carbondale, IL

2 Outline Differences between mosses and liverworts Basic morphology of mosses True mosses Key characters Sphagnum Morphology Major groups Basic morphology of liverworts Key characters A few words about names

3 How are bryophytes unique Life cycle Sex chromosomes Leaves petioles, lamina, costa, cuticle Desiccation tolerance (vs. avoidance) Water relations (poikilohydric - rheophytes, emergents, aquatic, mesophytes, xerophytes) Polyphenols (mosses) Mycorrhizae (mosses vs. liverworts)

4 C. Allen (1917) Sex Chromosomes

5 Sporophyte: (Mosses) peristome, stomates, operculum (Liverworts) no peristome, no stomates, no operculum (Liverworts)

6 Branching patterns Sympodial (connected modules) Monopodial (independent subsidiary modules) Sporophyte position Acrocarpy Pleurocarpy Growth form Erect (Orthotrophic) Prostrate (Plagiotrophic) Pendent Monopodial, pleurocarpous, erectl

7 Growth form Sympodial, acrocarpous, erect moss with new growth (Ptychostomum pseudotriquetrum)

8 Leaf characters: costa, margins, apex shape

9 Leaf cells: position on leaf, shape, bordering cells

10 Alar cells

11 Undulate leaves

12 Decurrent leaves

13 Rhizoidal tomentum

14 Rhizoidal tomentum

15 Paraphyllia Scale-like or filamentous, green appendages found along the stems of some mosses. Compare to: Stem-borne rhizoids that are filamentous and nongreen

16 Paraphyllia close up

17 Pseudoparaphyllia Pseudoparaphyllia are scale-like appendages that surround lateral buds on pleurocarpous mosses

18 Leaf cell ornamentation - papillae

19 Drepanocladus (sensu lato) Drepanocladus ---- aduncus, polygamus Entire upper leaf margins, enlarged alar cells Scorpidium ---- revolvens, cossonii, scorpioides Hyalodermis Warnstorfia ---- fluitans, exannulatus Slender, serrulte upper leaf margins Hamatocaulis ---- vernicosus Fish hook stem apex Sanionia ---- uncinatus Very plicate, coarsely serrate, long leaves

20 Drepanocladus

21 Scorpidium S. scorpioides

22 Hamatocaulis vs. Scorpidium revolvens

23 Hamatocaulis

24 Warnstorfia

25 Others of importance Campylium stellatum Pseudocalliergon trifarium Calliergon giganteum Paludella squarrosa Calliergonella cuspidata

26 Polytrichumtype mosses

27 Sphagnum Unique group of plants Two genera, about 200 species worldwide Very old lineage, but only diversified only 30 million years ago in the Miocene Most diversity in the tropics

28 Essential War Work The following are extracts from a memo concerning Moss Gathering by Adam Forman offering advice to other organisations:

29 The ideal method is to camp the workers on, or near, the moor, with transport stationed near at hand. Where this is impossible workers must be conveyed to and from the moors, and much valuable time and transport is expended on the journey. The work should be concentrated on a definite area, and no scattered working should be permitted. Workers should start in line, work forwards, and keep in line. When gathering is in very wet places, over say 14 or 18 inches deep in water and mud, a good plan is to fill the sacks only about threequarters full, drag then to the nearest hard ground and dance on them to extract the larger percentage of water. All gatherers should be provided with weed forks. The flat blade of the prongs should be vertical, and not horizontal to the ground. These forks to-day cost about 1/- each, and can be obtained from any ironmonger, but it is necessary to get a permit from the Ministry of Munitions.

30 Workers should not bring their own food. It should be provided for all, and be made as simple as possible. Meal-times should be set, and the food made ready for the workers. A large fish kettle is useful and beyond this, and cups, no utensils are necessary. All gatherers should understand that they are doing essential war work and should undertake to carry out instructions. Where civilian and military workers are mixed, the civilians must obey orders on a par with the military workers. Owing to the present congested condition of railways, waggons must be loaded to full capacity, and must be loaded and unloaded quickly. Waggons must be ordered ahead, and due consideration must be paid to the present over-worked condition of railway staff.

31 Branch leaf and stem, hyaline cells, green cells

32 Basic Sphagnum morphology

33 Capsules and pseudopodia

34 Pores of branch leaves

35 Convex, Concave sides of leaf, Cross-section

36 Stem leaves

37 Resorption and stem leaf pores of Sect. Sphagnum

38 Sphagnum sect. Sphagnum Capitulum with branches and leaves Resorption on dorsal (convex) surface. Fibrils on branch and stem hyalodermis magellanicum, centrale (papillosum)

39 Section Sphagnum branch fibrils

40 Sphagnum sect. Squarrosum Prominent apical bud Tendency for squarrose branch leaves Fimbriate stem leaves squarrosum, teres

41 S. teres stem leaf

42 Sphagnum sect. Acutifolium One pendent branch Green cells triangular, exposed on concave surface. fuscum, capillifolium, fimbriatum, russowii, warnstorfii, girgensohnii, (rubellum)

43 Sphagnum sect. cuspidatum Prominent apical bud in some species, brown coloration, ranked branch leaves. Green cells triangular, exposed on convex surface. angustifolium, fallax, majus, jensenii, riparium, lindbergii, balticum

44 Liverworts and the Doctrine of Signatures Brunfels herbal, 1590 Hepatica vulgaris maior f. officinarum italiae

45 Liverworts Leafy Simple thalloid Complex thalloid Key differences with mosses are in development

46 Apical cell, merophytes, and leaf arrangement A = Moss B = leafy liverwort

47 Development of gametophore A = Moss B = Leafy liverwort

48 Simple thalloid (Pellia)

49 Complex thalloid - Marchantia

50 Leafy liverworts

51 Leafy liverwort succubous Leaf insertion

52 Incubous leaf insertion

53 Complicate-bilobed, underleaves

54 Leaf cells and marginal teeth

55 Liverworts in peatlands Mylia anomala round succubous leaves, yellow gemmae Scapania complicate-bilobed leaves Lophozia - succubous bilobed leaves Cephalozia tiny, succubous bilobed leaves Lepidozia reptans tiny hands- incubous 3-lobed leaves Calypogeia incubous, bidentate at apex

56 Nomenclature Binomials and authors -- what do they tell you Drepanocladus polygamus (Schimper) Hedenas Amblystegium polygamum Schimper --- (The basionym) Campylium polygamum (Schimper) C. Jensen Also: a generic split - Mnium (s.l.) into Mnium (s.s.), Plagiomnium, Rhizomnium The generic name Mnium- stays with the type species.