Fossombronia Raddi is classified in the family Codoniaceae of the Metzgeriales (Grolle. 1983) which is a predominantly thalloid order of the Hepaticae. Fossombronia is unusual in that is shows two rows of lateral thallus lobes which are leaf-like and are normally called leaves. These are, however, quite different from the leaves of the so-called leafy liverworts, Jungermanniales, so that despite its leafy habit Fossombronia is unlikely to be confused with any member of that very large order. The prostrate fleshy stem, bearing reddish rhizoids, is also distinctive for most Fossombronia species.

The stem is more or less plane dorsally and convex ventrally. Internally the cells are uniformly thin-walled. The leaves are obliquely inserted with the antical margin decurrent. They tend to be crowded towards the stem apex and vary in shape even on a single stem, but are usually broader than long and have an irregularly undulate, lobed outline, with a few scattered mucilage papillae on the margin. In structure the leaves are for the most part unistratose but at the base become pluristratose. Individual cells are uniformly thin-walled and gradually increase in size, particularly in length, towards the base of the leaf. In all New Zealand species they contain chloroplasts and a variable number (4-40) of ellipsodial oil bodies, 1.8-2.6 × 4-4.8 μm. At a magnification of x100 the oil bodies appear smooth and glistening but at x500, using Nomarski interference microscopy, they appear botryoidal with a single eccentric large spherule. They resemble the oil bodies of Lophozia silvicola (Schuster, 1966; Fig. 13.9).

As regards sexual reproduction the species are either monoicous or dioicous. The young sporophyte is enclosed by a thin calyptra and by a more conspicuous campanulate pseudoperianth. Further protection may be provided by the crowded terminal leaves. The capsule is spherical and has a bistratose wall with the inner layer strengthed by nodules and irregular incomplete rings of thickening.

It is widely recognised (Scott, 1985) that, since species of Fossombronia vary considerably in morphology, according to environmental conditions, reliance cannot be placed on vegetative characters for separating them, particularly if herbarium specimens only are available for examination. However, should spores be present, the size of these, together with the ornamentation pattern on the surface, has proved to be distinctive for most species, even though ripe spores have been found to undergo post-harvest shrinkage and so are slightly smaller than those freshly shed.

Key to the New Zealand species:

Fossombronia reticulata Steph
Distribution

As far as is known F. reticulata is endemic to New Zealand. It is widely distributed throughout the country. Recent collections are from stream banks near Norsewood, roadside banks on Banks Peninsula and in the Akatarawa Range, and drain banks at Massey University. It also occurs as a weed in some bowling greens.

References and sources of material

F. reticulata was described in Latin by Stephani (1984; 1900) from a specimen collected near Auckland, New Zealand by T. Kirk and now housed in the Stephani Herbarium at Geneva. A syntype is at CHR. The type and syntype were examined as well as other specimens from the collections of E.A. Hodgson, K.W. Allison and W. Colenso.

Plants from recent collections were cultured at Massey University on a sterilised clay soil in plastic containers and observed over three years.

Description of the plant

Plants tend to grow in tufted, yellowish-green to green cushions, up to 20cm in diameter. Individual shoots, 1-5cm long, are terminally erect but basally prostrate and attached to the soil by numerous long crimson rhizoids. The breadth of the shoot including the leaves is up to 6mm. Branching is intercalary with new shoots arising in a supra-axillary position and usually from the basal part of the plant.

The stem region, 0.9mm broad and 0.26mm deep, consists of the thin-walled cells of width 40-60 μm, depth 40-60 μm and length 120-230 μm. The leaves are of firm texture, 2-(3)mm long and 2-2.5(-4)mm broad, widely spreading to suberect, either distant or slightly imbrticate, execept where they are crowded near the stem apex, more or less crisped and rounded with 2 to 4 shallow lobes, which on the margin may show one or more angular projections, each terminated by a mucilage papilla. Except in very young plants the leaves tend to be opposite to subopposite with the antical margin long decurrent.

Plants are dioicous. In male plants numerous antheridia occur on the upper surface of the stem amongst the terminal leaves (Fig. 1a). Each anteridium has a short stalk and a spherical head, 0.21mm in diameter, which is often conspicuous by its yellow colour but with age becomes whitish. In female plants (Fig. 1b) page 14

Fig. 1 Fossombronia reticulataA. Male shoot showing antheridia. b. Female shoot showing sporophyte and pseudoperianth. Drawing by C.A. Korndorffer.

archegonia arise on the stem near the apex. The pseudoperianth is campanulate, 3-4mm high and 3mm in diameter across the slightly crispate, lobed rim. Around it the crowded terminal leaves form an outer cup. The ripe capsule has a firm stalk, 1-2cm long and 0.4mm wide, and a spherical, dark brown head 1.1mm in diameter. The spores have a diameter of (24-) 26-29(-32) μm. The surface is finely ornamented with irregularly reticulate, sinuous, low lamellae which are more clearly defined on the distal face and appear as truncate projections around the rim (Fig. 3). The elaters are mostly 0.5-0.8 μm wide and 70-29 μm long, colourless except for two helical brown bands but in some populations a few are 3-banded at the middle where they are slightly wider (to 1.0 μm).

Note:F. reticulata is proving to be a troublesome weed in some bowling greens and golf courses, apparently favoured in comparison to more desirable plants by some spray programmes. Research is currently being carried out in regard to this.

It has been observed that, after the spraying of roadside banks on the Akatarawa Road with 2,4,5-T F. reticulata was one of the first plants to appear. The green cushions were very conspicuous on the bare clay soil. Investigation showed that, although the spray had killed the parts of the Fossombronia with which it came in contact, it evidently was not translocated within the plant, for new shoots rapidly developed either from resistant apices or advenitiously from stems that were underneath the cover of dead leaves.

Fig. 2Spore ofF. reticulata.
Top:distal view.
Middle:side view.
Bottom:proximal view. Scanning electron micrographs by D. H. Hopcroft and R. Bennett. Scale bars = 10 μm.
Fig. 3Spore ofF. australis. Top and Middle:distal view taken from different angles.
Bottom:proximal view. Scanning electron micrographs by D.H. Hopcroft and R. Bennett. Scale bars = 10 μm.

Fossombronia australis Mitt
Distribution

Fossombronia australis is known from Kerguelen Island and from New Zealand. The type came from Heard Island in the South Indian Ocean (Bonner, 1965). It may occur also in Australia, although records from that country require confirmation from a wider range of specimens. In New Zealand it grows either amongst other vegetation on wet, shady banks or as dense, partially submerged colonies in freshwater swamps and Sphagnum mires.

References and sources of material

This species was described by Mitten in 1876 from specimens gathered in Heard Island by H.N. Moseley, naturalist to the Challenger Expedition. The specimens were without fruit (Mitten, 1876a). Further on in the same journal there is another description of F. australis by Mitten, this time from specimens with young capsules, which were collected in Kerguelen Island at Royal Sound, Vulcan Cove by A.E. Eaton (Mitten, 1876b). Three years later Mitten again described F. australis (Mitten, 1879) and listed the distribution as Kerguelen Island, Moseley; Royal Sound, Vulcan Cove, with young capsules, Eaton; (Heard Island) Moseley.

Stephani (1900) gave a description of F. australis and that the spores described by Mitten were spore mother cells; he questioned whether they belonged to this species. He gave what he considered to be a correct description of the spore, based on a few still retained in a capsule. They are said to be 32 μm in diameter and densely covered with short truncate papillae. However, his description of the leaf appears to be from a poorly preserved specimen. The distribution is given as Kerguelen (Eaton), New Zealand (Colenso). Stephani also made drawings of the spore, elater and leaf of F. australis. The last of these shows the shape, vertical orientation and deep grooves typical of the species.

Immediately following the description of F. australis and in the same subdivision of the genus, Stephani (1900) described F. gigantea n. sp. This name in my opinion is a synonym of F. australis (see later).

Specimens in the Mitten Herbarium collected from Kerguelen Island by Eaton and by Moseley were examined at the Herbarium of the New York Botanical Garden. No spores are present and all appear to be male plants. Specimens from New Zealand were identified in the collections of E.A. Hodgson and of K.W. Allison. Many of these are also male plants, but a few have sporangia. Fresh plants were collected from the trial plots at the Turf Research Institute. Palmerston North and some of these were cultured at Massey University.

Description of the plant

Plants grow in colonies of a predominantly yellow-green colour, often merging into reddish at the bases of the leaves and into reddish-brown in the stems and older parts. At times the whole plant is reddish-brown. Individual shoots branch a few times and are large, being up to 5cm long and 13mm wide including the leaves. When growing on banks the shoots are prostrate and attached by reddish rhizoids, but when growing in mires the shoots are erect and apart from emergent tips are submerged, with rhizoids either very short or lacking. The stem is 1-1.5mm broad and 0.3-0.5mm deep. The older leaves are large, 2.5-4mm long and 5-8mm wide, alternate, closely imbricate, in overall shape reniform, distally deeply folded page 17 lengthwise 2 or 3 times, of thin texture, crisped, usually entire but sometimes slightly angled or very shallowly crenately lobed. Orientation is vertical.

Plants are dioicous. In male plants about 10 to 12 antheridia are found dorsally on the stem, arranged so that there are 1 to 4 in the vicinity of each leaf. The antheridium has a short stalk and a spherical head about 0.3mm in diameter. In female plants archegonia appear amongst the terminal leaves but due to continued growth of the stem the sporophytes become located dorsally. The campanulate pseudoperianth is large, up to 6mm long and 2mm across the shallowly lobed rim. It is partially enclosed by the adjacent leaves. The brown spherical capsule, of diameter 1mm is elevated on a firm stalk up to 11mm high. The golden-brown spores (Fig. 4) have a diameter of 29-37 μm. The distal face is described by Stephani (1900) as being densely muricate with low papillae, but when viewed from some angles the projections appear more as irregular short lamellae. On the proximal face the lamellae are lower and more crowded. The elaters are of two kinds. Most are slender. 5 × 145 - 225 μm, with 2 helical bands of thickening; others are shorter and wider, up to 13 × 100 μm, with 3 or 4 bands.

Fossombronia wondraczekii (Corda) Dum
Distribution

This species is widespread in Europe and North America and has been reported also from North Africa (Bonner, 1965) and from Australia (Scott, 1985). A taxon from Japan has been called F. wondraczekii var. loitlesbergii (Inoue, 1973). F. wondraczekii has not been recorded for New Zealand previously but has now been found in the Wairarapa, on banks in pasture country in Hawke's Bay, in the Kaingaroa State Forest, and in Northland.

It is commonly found on bare soil, as in cultivated fields, on infrequently used paths and at the margins of drains.

References and sources of material

Stephani (1900) provided a Latin description of the species under the name F. cristata Lindb. (misprinted as crispata in the text). A more recent description in English is given by Scott (1985) and earlier shorter ones by Mueller (1906-11) and by Frye and Clark (1937). They also provide illustrations, as does Landwehr (1980). The fresh material used in the present study was collected by D. Havell from small silty knobs on the edge of Lake Wairarapa on 15:1:1987. It was later maintained in culture at Massey University. Herbarium material was examined from the collections of E. A. Hodgson, from Botany Division, D.S.I.R., and from Europe.

Description of the plant

The rather delicate, bright green plants occur singly or as small patches and are attached to the soil by violet rhizoids. Individual shoots may be simple or may branch once or twice; they are up to 2cm long and 2-3mm wide. The stem is up to 1mm wide and 0.7mm thick. The leaves are longitudinally inserted, opposite, or almost so, and crowded towards the tip of the stem, but alternate and varying further back. They range from 1 to 3mm in both length and breadth and vary in overall shape from oblong to quadrate. They may be either plain or crisped at the margin, entire or variously lobed, with the lobes frequently acute.

This species is monoicous. Archegonia are scattered on the dorsal surface of the stem and whitish antheridia occur nearby among the apical leaves. The pseu- page 18

Fig. 4Spore ofF. wondraczekii.
Top:distal view.
Middle:side view.
Bottom:proximal view. Scanning electron micrographs by D.H. Hopcroft and R. Bennett. Scale bars = 10 μm.
Fig 5.Spor ofF. pusilla.
Top:distal view.
Middle:side view.
Bottom:proximal view. Scanning electron micrographs by D.H. Hopcroft and R. Bennett. Scale bars = 10 μm.

page 19 doperianth is campanulate to turbinate, 1.5-4.0mm high and 1.0-3.5mm wide across the shallowly lobed rim. The sporophyte has a stalk 2-5mm high and a spherical brown capsule 0.5-0.6mm in diameter. The spores are lamellate (Fig. 5) with nearly parallel sinuous lamellae radiating out from the centre of the distal face and appearing in profile at the margin as about 30 (28-36) spines.

Sometimes the lamellae show a tendency to merge into areolae at the centre of the distal face. The proximal face is papillate to feebly lamellate. Spore diameter is rather variable, the range being (40-) 45-47 (-52) μm. Elaters are simple or occasionally V-shaped or forked, 8-9 (-13) μm wide and 50-80 (-105) μm long, usually with 2 helical bands but occasionally with up to 4.

Fossombronia pusilla (L.) Nees
Distribution

This is a cosmopolitan species. It is found in similar sites to F. wondraczekii such as damp clay soils and the sides of drains. In New Zealand the two species may even be intermixed. It has been recorded for New Zealand by Gottsche, Lindenberg and Nees (1844-7), by Mitten (1855) and by Allison and Child (1975).

References and sources of materials

The species has been described and illustrated many times since Linnaeus (1753) called it Jungermannia pusilla. Recent treatments are by Scott (1985) based on Australian material, by Paton (1973) and Landwehr (1980) for European material and by Allison and Child (1975) for New Zealand material. Scott noted that there is a considerable degree of variation between populations. Paton (1973) recognised two varieties and these occur also in Australia (Scott, 1985). So far only var. pusilla has been found in New Zealand.

Fresh material was collected and studied in Europe and from the sides of the drain opposite Woodville Reserve, New Zealand. Herbarium material was examined at the British Museum, the Senckenburg Herbarium, Frankfurt and in the collections of E. A. Hodgson, of Botany Division, D.S.I.R. and of the National Museum, New Zealand.

Description of the plant

Plants grow singly, in scattered patches or in large colonies. The bright green, prostrate shoots are 1-1.5cm long, either simple or once to twice branched and attached to the soil by numerous violet rhizoids. The stem is slender, being 0.5-2mm wide and 0.4-0.7mm thick. The leaves are inserted obliquely and vary in orientation from transverse to longitudinal, and from plane to crisped at the margins. They also vary considerably in shape but in general are reniform, 0.8-2.6mm long and 0.8-4.4mm wide, and may be entire, emarginate or irregularly lobed and angled.

Plants are monoicous. Antheridia appear first and are conspicuous on the upper surface of the stem by their yellowish colour. Later archegonia appear on the upper surfacce of the stem near the apex. Sporophytes are produced in abundance. Each has a short, fragile stalk about 3mm high and a brown spherical capsule of diameter 0.8mm. The companulate pseudoperianth is 2-3mm high and up to 3mm wide across the rim which is irregularly scalloped and often somewhat crisped. The spores (Figs. 5 and 6) have a diameter of about 50 μm (42-56). The distal face is ornamented with forking or radiating lamellae which sometimes join to form an ill-defined, or rarely a complete, network. They appear in profile at the page 20 margin as 10 to 17 spines which are often connected by an incomplete perispore. The proximal face is ornamented with papillae and short, ill-defined lamellae. The elaters have a length of 190-230 μm and 2 or occasionally 3 helical bands of thickening.

Notes on other species listed for New Zealand by Hamlin (1972)

Fossombronia perpusilla (Col.) Steph.

Colenso (1885) described a new species Noteroclada perpusilla from plants page 21

Fig 6. Left: Distal view of the spore of F. pusilla. Scanning electron micrograph by D.H. Hopcroft and R. Bennett from the same capsule as Fig. 5.
Right: Distal view of spore of F. perpusilla. Reproduced by permission of the Stephani Herbarium. Geneva. Scale bars = 10μm.

which he had found at Scinde Island, Napier. Later Stephani (1900) transferred the species to Fossombronia.

The isotype used by Stephani and labelled “New Zealand, Colenso” was examined together with scanning electron micrographs of the spores, one of which is reproduced here (Fig. 6). It is most likely that the original plants are represented also by the packet, Colenso 6498, in the Herbarium of the National Museum of New Zealand (WELT) and labelled as collected at Scinde Island, Napier. Since the specimens correspond with F. pusilla, the name F. perpusilla considered to be a synonym.

Addendum

Since this paper was submitted there has been an opportunity to examine the sheet of F. australis at the British Museum. It contains 6 smaller sheets of specimens. Three of these comprise male plants collected by Moseley from Heard Island; they were labelled as type material of F. australis Mitt. by B.M. Thiers on July 13, 1982. The other three were collected by E.A. Eaton on Kerguelen Island, one from Royal Sound and the other two from the hill N.W. of Mt. Crozier. One of the latter shows a plant with capsules and another a plant with antheridia. The antheridia are situated along the stem in an arrangement quite different from the terminal cluster of antheridia in the Heard Island plants. There is also a scanning electron micrograph of the spores taken by Pike and Scott.

Specimens labelled F. australis in the Stephani Herbarium at Geneva were also examined. There were two from Kerguelen Island, collected by Eaton, but none from Heard Island. They were accompanied by a copy of Mitten's drawing of a pseudo-perianth, and of spore mother cells containing spores, with a comment on the latter by Stephani “These are from a fungus”.

Since the name F. australis was first given to the Heard Island plants, a new name must be found for the ones from Kerguelen Island. They appear to correspond page 22 with F. naumanni Schiffn. which was named by Schiffner in 1889 from material collected by Naumann on Kerguelen Island (Bonner, 1965). A more recent description based on Australian plants and accompanied by illustrations is given by Scott (1985). The correct name for the New Zealand plants referred to as F. australis in the present paper would then be F. naumannii. The known distribution is Kerguelen Island, Macquarie Island, Australia and New Zealand. Scott (1985) gave no details regarding antheridia. He described a different type of elater from that occurring in New Zealand material but, since capsules are rarely found, it has not been possible to determine how widespread or significant this might be.

Acknowledgments

The writer is indebted to the curators of the herbaria at the Stephani Herbarium Geneva, the Senckenberg Naturmuseum Frankfurt, the State University Utrecht, the New York Botanical Garden, the British Museum. Botany Division Christ-church and National Museum of New Zealand, Wellington, for the opportunity to study herbarium specimens; to D. Havell, H. Wilson and C. Meurk for providing fresh material and to the Assistant City Engineer (Works) for information regarding the spray programmes carried out by the Upper Hutt City Council on Akatarawa Road.

References

Allison, K.W., and Child, J. 1975: The Liverworts of New Zealand. University of Otago Press, Dunedin.

Bonner. C.E.B. 1965: Index hepaticarum 5. J. Cramer, Weinheim.

Colenso, W. 1885: A description of some newly-discovered and rare indigenuous plants: being a further contribution towards the making known the botany of New Zealand. Transactions of the New Zealand Institute 17 : 237-263.

Frye, T.C. and Clark, L. 1937: Hepaticae of North America 6 : 151-161. University of Washington. Seattle.

Gottsche, C.M.; Lindenberg, J.B. and Nees von Esenbeck, C.G. 1844-47: Synopsis Hepaticarum. Meissner, Hamburg.

Grolle, R. 1983: Nomina generica Hepaticarum; references, types and synonymies. Acta Botanica Fennica 121 : 1-62.

Hamlin. 1972: Hepaticae of New Zealand Parts I and II. Records of the Dominion Museum 7: 243-366.

Herzog, Th. 1935: Descriptions of new species of New Zealand Hepaticae. Transactions of the Royal Society of New Zealand 65 : 350-356.

Inoue, H. 1973: The genus Fossombronia Raddi in Japan. Journal Hattori Botanical Laboratory 37 : 293-297.

Landwehr, J. 1980: Atlas Nederlandse Levermossen. Koninklijke Nederlandse Natuurhistorische Vereiniging.

Linnaeus, C. 1753: Species Plantarum. Holmiae.

Mitten. W. 1855: Hepaticae. In J.D. Hooker. The Botany of the Antarctic Voyage of H.M. Discovery ships Erebus and Terror. II Flora Novae Zelandiae Part 2. Flowerless Plants. Reeve. London.

Mitten, W. 1876a. The Musci and Hepaticae collected by H.N. Moseley. naturalist to H.M.S. Challenger. Journal of the Linnean Society of London (Botany) 15 : 59-73.

Mitten, W. 1876b: List of Musci and Hepaticae collected in Kerguelen's Island by the Rev. A.E. Eaton. Journal of the Linnean Society of London (Botany) 15 : 193-197.

Mitten, W. 1879: Hepaticae. In Account of the petrological, botanical and zoological collections made in Kerguelen's Land and Rodriguez during the Transit of Venus Expeditions carried out by order of Her Majesty's Government in the years 1874-1875. Philosophical Transactions of the Royal Society of London 168 : 187-196.

Mueller, K. 1906-11: Die Lebermoose Deutschlands. Oesterreichs und der Schweiz. In Rabenhorst's Kryptogamen-Flora 6, Leipzig.

Paton, J.A. 1973: Taxonomic studies in the genus Fossombronia Raddi. Journal of Bryology 7: 243-252.

Schuster, R.M. 1966: The Hepaticae and Anthocerotae of North America. Columbia University Press, New York.

Scott. G.A.M. 1985: Southern Australian Liverworts. Australian Government Publishing Service, Canberra.

Stephani, F. 1894: Hepaticarum species novae. Hedwigia 33 : 9 Stephani. F. 1900: Species hepaticarum 1 : 384.