Species Of Anthoceros Research Articles

A revision of the genus <i>Anthoceros</i> (Anthocerotaceae, Anthocerotophyta) in China

The genus Anthoceros (Anthocerotaceae, Anthocerotopsida) in China is reviewed. Five species and one variety are recognized. Anthoceros alpinus, A. bharadwajii, and A. subtilis, are reported new to China. Aspiromitus areolatus and Anthoceros esquirolii are proposed as new synonyms of Folioceros fuciformis and Phaeoceros carolinianus, respectively. A key to the species of Anthoceros in China is provided.

(1596‐1597) Proposals to conserve the name Anthoceros with a conserved type and the name Anthoceros agrestis against A. nagasakiensis (Anthocerotophyta)

When Linnaeus (Sp. PI.: 1139. 1753) named the genus he included three species, namely, A. punctatus, A. laevis, and A. multifidus. multifidus was later removed from the genus and transferred to Riccardia by Gray (Nat. Arr. Brit. PI.: 684. 1821 'Riccardius') leaving two of the original species in the genus Anthoceros. punctatus was selected as the generitype by Proskauer (Ann. Bot., n.s. 12: 259. 1948). His selection remained uncontested until Schuster (J. Hattori Bot. Lab. 26: 299. 1963) suggested that Proskauer should have selected A. laevis as the type rather than A. punctatus. That is because Proskauer later decided (Bull. Torrey Bot. Club 78: 346, 1951) that these two original species of actually represented two different genera. Since he had selected A. punctatus as the type, it had to remain with Anthoceros, so he transferred A. laevis to his new genus Phaeoceros (Proskauer I.c., 1951). punctatus had long been considered to be conspecific with Aspiromitus husnotii Steph., the generitype of Aspiromitus Steph. (Proskauer, I.c., 1948: 262), and Schuster (I.c., 1963) stated that Aspiromitus, typified by A. husnotii (= A. punctatus) must be used for one of the two elements originally included in by Linnaeus, and must be retained for the other ('law of residues'). Following his logic, the two species of Linnaeus would then be laevis and Aspiromitus punctatus; he did not, however, make any new combinations in 1963. Schljakov (Novosti Sist. Niz. Rast. 13: 225. 1976) agreed with Schuster (I.c., 1963) and implicitly lectotypified with laevis, making the new combination Aspiromitus punctatus (L.) Schljak. Grolle (Acta Bot. Fenn. 121: 5. 1983) pointed out that such a later lectotypification was contrary to the provisions of the ICBN, particularly with the removal of any appeal to the law of residues in the edition adopted at the Sydney Congress of 1981 (Voss & al., Regnum Veg. 111. 1983) and had to be rejected. That would have been the case except for the provision of the ICBN, first adopted at the Seattle Congress in 1969 (cf. Art. 8 (last clause) in Stafleu & al., Regnum Veg. 82. 1972), and now expressed as Article 10.5(b) of the ICBN (Greuter & al., Regnum Veg. 138. 2000) that a choice of lectotype for the name of a genus or subdivision of a genus may be superseded if . . it was on a largely mechanical method of selection. The selection by Proskauer (l.c., 1948: 262) was obviously mechanical since he wrote: Anthoceros punctatus was described by Linne (1753) as the first species of Anthoceros. It is here, therefore, considered as the type of the genus. Although the actions of Schuster (l.c., 1963) and Schljakov (l.c.) do not represent formal designation of a type as required by Art. 7.11 of the ICBN, more recently Schuster (Hepaticae and Anthocerotae of North America 6: 745. 1992), following his description of Anthoceros, wrote: Type. laevis L. The reasons for the present type designation are discussed at length, below. Although this later designation was solely upon the law of residues with no mention whatsoever of the mechanical choice by Proskauer (l.c. 1948: 262), Art. 10 Ex. 7, a voted example, makes clear that any later type designation that meets the requirements of Art. 7.11 supersedes a choice based on a largely mechanical method of selections. Therefore, unless the Proskauer designation of A. punctatus is conserved as the type of the name Anthoceros, it must be considered to have been superseded by Schuster's (I.c. 1992: 745) choice of A. laevis. With A. laevis as the generitype, the species of Phaeoceros must either be returned to or transferred to and all species now considered to be members of must be transferred to Aspiromitus. Schuster (l.c., 1992) and Schljakov (l.c.) have already begun this lengthy task to a very limited extent. Not only will the number of new combinations be high, including well over 100 of the 293 binomials listed by Bonner (in Index Hepat. 2. 1962) under Anthoceros, the confusion this will cause will be unprecedented. This will likewise result in changing the generic name for 131 sequences

Ultrastructural Characteristics of the Placental Region of Folioceros and Their Taxonomic Significance

In Folioceros the gametophytic and sporophytic tissues are closely intermingled, much more like the foot region of Phaeoceros than the widely separated gametophytic and sporophytic tissues typical of many species ofAnthoceros. Although the foot regions of the two Folioceros species studied are similar in some respects to those of other species of Anthoceros (e.g., presence of a palisade layer), the presence ofsmall (2-3 nm periodicity) protein crystals and the close intermingling of gametophytic and sporophytic tissues are distinct from most of the Anthoceros species. Based on our findings, we conclude that Folioceros should be separated from Anthoceros at the subgeneric level. Bartlett (1928) and Renzaglia (1978) documented the differences in the foot, the basal region of the sporophyte embedded in the gametophytic tissue, in various genera of hornworts. These differences include size of the foot, regularity of cell divisions, and relative size of sporophytic and gametophytic cells in the placental region. In most of the genera there is an intimate contact between the cells of the

Immunochemical Evidence That Abscisic Acid Is Produced by Several Species of Anthocerotae and Marchantiales

Several species of Anthoceros were analysed for abscisic acid (ABA). They all contain ABA-like immunoreactive material based on a combined HPLC-monoclonal-antibody-ELISA- analysis. The stomata-bearing sporophytes and the tubers of A. dichotomus contain significantly more ABA-immunoreactivity than the stoma free thallus. The concentration of this material in the sporophytes increases with tissue age, resulting in a high level in the apical parts. When 14C-ABA is applied to apical or basal parts of the sporophyte, radioactivity moves preferentially basipetally and enters the gametophyte. After application to the gametophyte, radioactivity distributes all over the gametophyte but does not enter the sporophyte. ABA-content of Anthoceros species which were harvested from a moist habitat is lower than in samples grown under slightly dryer conditions. Sporophytes of A. laevis exhibit a stress-induced ABA biosynthesis. Stomata from Anthoceros sporophytes respond to ABA-(closing) and fusicoccin (FC)-treatment (opening). Several stomata- free species of Marchantiales were analysed too for ABA. They all contain ABA-like immunoreac- tivity. Particularly the desiccation tolerant species Exormotheca and Plagiochasma have very high amounts of this material.

Sexual Life Cycle of Three Species of Funariaceae in Culture

Three species of the Funariaceae (Physcomitrella patens (Hedw.) B.S.G., Physcomitrium pyriforme (Hedw.) Hampe and Funaria hygrometrica Hedw.) have been cultured under sterile conditions on Knop's inorganic me- dium (liquid and agar) to determine the conditions and minimum time nec- essary for completion of the sexual life cycle (spore to spore). According to the data presented, the life cycle of F. hygrometrica may be completed in 4 months, P. pyriforme in 3 months and P. patens in 2 months. In all three species the critical factor for the induction and maturation of gametangia is cold temperature. Delineation of the life cycle makes these organisms suitable for genetic study. Studies concerning the reproductive phase in bryophytes in culture have been relatively few. Voth and Hammer (1940) implicated photoperiod as the stimulus nec- essary for gametophore production in Marchantia. Morris (1961) stated that in five species of leafy liverworts the onset of sexual reproduction is controlled primarily by photoperiod. Benson-Evans (1964) reported that four species of Marchantiales and six of Jungermanniales are long-day plants, while Riccia glauca and Anthoceros laevis are short-day plants. She also cited some evidence that the photoperiodic effect is operative in many liverworts only within certain temperature limits. Ridgway (1967) reported that in species of Anthoceros, Phaeoceros and Notothylas, photoperiod is critical in initiation of antheridia while temperature has little effect. Contrary to the cases reported for the liverworts and hornworts, temperature does seem to be the

Factors Initiating Antheridial Formation in Six Anthocerotales

In species of Anthoceros, Phaeoceros, and Notothylas, photoperiod is the critical environmental factor in the initiation of antheridia while tempera- ture (10-250 C) has little effect. The purpose of this investigation was to study some environmental factors which effect the initiation of sexuality in several species of Anthocerotales as evidenced by the formation of antheridia. Although numerous studies of environmental stimuli which induce the reproductive phase in algae, fungi, and flowering plants have appeared, only recently have such studies of hepatics been reported. Photoperiod was implicated in gametophore pro- duction in Marchantia (Voth & Hamner, 1940; Anthony, 1962) and in the initiation of sexuality in five species of Jungermanniales (Morries, 1961). Recently, extensive investigations of conditions which evoke initiation of sexuality in liverworts have been published by Benson-Evans (1965), who reported that four species of Marchantiales and six of Jungermanniales are long-day plants (16-18 hours of light diurnally), while Riccia glauca and Anthoceros laevis are short-day plants (6-8 hours of light diurnally). She also cited some evidence that the photoperiodic effect is operative in many liver- worts only within certain temperature limits. In Preissia quadrata, Pellia epiphylla, and Anthoceros laevis, however, the photoperiodic induction of sexuality is operative over a wide temperature range, she found. In Cryptothallus mirabilis (Benson-Evans, 1961), temperature alone, particularly during the dark period, appears to be most influential. Monroe (1965) also found that temperature was the limiting factor in inducing sexuality in the moss Funaria hygrometrica.

Some Liverworts from the Philippines

Sixteen families, 27 genera, and 72 species of Hepaticae are listed from the Philippines. The liverwort flora of the Philippines is still largely unknown. Stephani (1900-1924) described some species merely cited from Philippina Insulae in his Species Hepaticarum. Small but important collections were listed by Merrill (1906), Merrill and Merritt (1910), Verdoorn (1930), Herzog (1931, 1932), and Evans (1934). Meijer (1957) reported two species of Anthoceros from Los Bafios, Laguna, and from Taal Volcano, Batangas. He also reported (Meijer, 1960) three species of Bazzania from Polillo Island, and from Mount Apo, Davao, Mindanao. Inoue (1964), in his monograph of Plagiochilion, reported two species, one without a definite locality and the other from Canlaon Volcano, Negros. Recently I examined the liverwort collections at the Philippine National Herbarium. Most of the specimens were collected by such outstanding collectors as Merrill, Elmer, Edafio, and Sulit. Most of the determinations were done by Dr. R. van der Wijk and Dr. S. Hattori. Inasmuch as reports of collections are scanty, widely scattered, and cannot easily be assembled, the following list of known records has been prepared. While far from complete, it will at least be a basis for future work. The arrangement of the families and genera follows Evans (1939).

Notes on Hepaticae of Southern California

Dr. M. A. Howe, in his Hepaticae and Anthocerotes of California mentions over eighty species of hepatics as occurring in the state. Only a small number of these species however are to be found in the southern portion of the state. In Southern California the country is for the most part very dry except during the winter months and there are no meadows and swamps, and but few trees. Even the mountain streams are dry the greater p rt of the year. Under these conditions one would not expect to find a great number of hepatics, yet certain species seem to thrive quite abundantly. During my past year in California I have explored quite thoroughl the region about Pasadena, Cal., including the canyons of the San Gabriel Mountains, besides visiting Catalina Island and Santa Barbara. Just outside the city the foothills begin to rise. The soil is a coarse gravel, and during the winter months this gravel is thickly covered with large patches of Fossombronia longiseta Aust. This species fruits quite freely in March, and a few weeks later, after the rains cease, the plant dries up and disappears. Often one will find Riccia trichocarpa M. A. Howe, mixed with the Fossombronia. This is the commonest of our Riccias and may be recognized by its grayish appearance, due to the small white cilia on the margin of the thallus. I found this species quite abundant last July at the Avalon golf links on Catalina Island, although the plant was hardly recognizable on account of its dried up condition. Riccia glauca is a larger species with wider and less divided thallus and the margins are without cilia. It is occasionally found growing on shady banks. The San Gabriel Mountains are cut up by numerous canyons. These canyon walls are often very steep, and there is usually a mountain stream running down through the canyon and forming a series of pretty waterfalls and cascades. Here, on the damp rocks, Porella Bolanderi (Aust.) Pearson grows in great profusion, often covering large areas. Occasionally this species is found growing on trees. It is a variable species, with some forms resembling Porella rivularis. In the smaller canyons, among the ferns, are a number of interesting hepatics. There is Cryptomitrium tenerum (Hook.) Aust., which in early spring sends up its stalked receptacles resembling tiny umbrellas; also Targionia hypophylla L., which bears its fruit on the under side of the thallus at the apex. This is our commonest hepatic, and may be found at all seasons of the year on any shady bank. I found it abundant this summer at Santa Barbara and Catalina Island. Shady banks will also yield several species of Anthoceros. These species, which are similar in appearance, are most easily determined by their spores. Anthocerosfusiformis Aust. is the largest species and