William D. Reese

Reproductivity, Fertility and Range of Syrrhopodon texanus Sull. (Musci; Calymperaceae), a North American Endemic

Syrrhopodon texanus Sull. is a dioicous moss endemic to eastern North America. It occurs mainly as two apparently allopatric populations: one in the Atlantic and Gulf coastal plains and the other in the interior. Smaller, isolated, outlying populations also occur. Ninety-five (about 19%) of the 509 herbarium specimens studied included plants bearing gemmae on specialized leaves at the stem tips at the time of collection. There is marked periodicity in gemma production, which becomes important in August (33% of the specimens collected in that month) and peaks in Septem- ber (50% of the specimens collected in that month), declining thereafter. Only 28 (about 5.5%) of the specimens, all from coastal plain sites, included plants bearing sporophytes. Male plants seem to be very rare; they were found only with sporophyte-bearing female plants in the coastal plain. Female plants are common, and apparently only female plants occur over most of the range of this moss.

The Genus Syrrhopodon in the Americas I. The Elimbate Species

Ten species of Syrrhopodon with the leaves not bordered above by elongated cells occur in the Americas. One species, S. incompletus, is represented by six varieties, including: S. incompletus var. perangustifolius Reese, var. nov.; S. i. var. lanceolatus (Hampe) Reese, comb. et stat. nov.; and S. i. var. bertero- anus (Brid.) Reese, comb. et stat. nov. Keys, descriptions and illustrations are provided for all taxa. This treatment includes all known American taxa of Syrrhopodon with the upper lamina of the leaf not bordered by elongated cells.3 It provides keys, descriptions, il- lustrations, synonymy and discussion of distribution, and is based primarily on herbarium specimens. In it, I have attempted to account for all names applied in the literature to North and South American taxa of Syrrhopodon with the upper lamina elimbate. Observations and measurements were made mostly from specimens mounted in Hoyers solution (Anderson, 1954). Dry plants of most of the taxa included here, especially those with colored leaf bases, are exceedingly slow to soak up water. Con- sequently, all specimens were first immersed in boiling water before dissection and preparation of permanent mounts.

Calymperes (Musci: Calymperaceae): World ranges, implications for patterns of historical dispersion and speciation, and comments on phylogeny

Refinements in the taxonomy of the genus Calymperes (Musci: Calymperaceae) allow increasingly accurate estimates of the total number of species worldwide and new assessments of world ranges of the species. Instead of the 272 correct names of Calymperes listed in Volume 1 of Index Muscorum, the world total of “good” species now appears to be in the range of 30 to 40, and contrary to the high degree of narrow endemism implied from the compilation of Index Muscorum, many species of Calymperes have broad ranges in the paleo- or neotropics. A few species, including C. afzelii, C. erosum, C. palisotii, C. lonchophyllum, and C. tenerum, are pantropical. World ranges of species of Calymperes are mapped and implications for historical patterns of dispersal and speciation are discussed. Suites of endemic species and species groups in the neotropics differ from those in the paleotropics, demonstrating different ancestries, a long period of geographic separation, and independent evolution in two fundamentally different environments. It is suggested that Calymperes shares close phylogenetic relationship with limbate Syrrhopodon.

A Natural Hybrid between Weissia and Astomum and Notes on the Nomenclature of the North American Species of Astomum

Hybrid sporophytes, resulting from natural hy- bridization between Weissia controversa and Astomum ludovi- cianum, are intermediate in characteristics between those of the parents. Some of the hybrid sporophytes failed to produce spores while in others the spores were frequently deformed and were largely or completely sterile. The three North Ameri- can species of Astomum are transferred to the genus Weissia. Both Weissia controversa and Astomum ludovicianum occur in abundance on the heavy clays of southern Louisiana. They fre- quently grow together and both produce sporophytes at about the same time, towards the end of the rainy season, in early spring. Thus conditions for their hybridization are potentially favorable in this area. Indeed we both have occasionally seen individual sporo- phytes, growing with those of Weissia and Astomum, which seemed to be intermediate in appearance between those of the two species. In March of this year, one of us (W.D.R.), while collecting in a low, wooded area in Lafayette Parish, found a lump of clay bearing a population of fruiting plants that seemed to include, among other species, Weissia controversa, Astomum ludovicianum, and a large number of individuals bearing sporophytes intermediate between those of the Weissia and Astomum. The lump of clay was, in fact, an almost perfect experimental set-up. It has been turned up by the passage of a vehicle through the wet woods; on one side of the lump was an almost pure stand of Weissia, and on the opposite side there was a dense growth of Astomum. Between the Weissia and the Asto- mum grew the plants with intermediate sporophytes. In addition there were also present a number of plants of Astomum muehlenbergianum,

Calymperes palisotii (Musci; Calymperaceae) Found in Dominican Amber

Calymperes palisotii Schwaegr. subsp. palisotii is reported for the first time from Dominican amber, with an age of 25-45 million years. This is the third record of the moss family Calymperaceae from Dominican amber. A total of 12 species of mosses is now known from Dominican amber, six identified at the species level and six at the genus level. All species and genera of mosses reported from Dominican amber are widespread in the Neotropics and still occur on the island of Hispaniola.

Tropical lowland mosses disjunct between Africa and the Americas, including Calyptothecium planifrons (Ren. & Par.) Argent, new to the Western Hemisphere

Calyptothecium planifrons (Ren. & Par.) Argent is reported new to the Western Hemisphere based on two recent collections from Brazilian Amazonia, in Para and Rondonia; C. planifrons was originally described from Madagascar. Forteen Other species of mosses with apparently disjunct distributions between tropical Africa and tropical America are also discussed. It is likely that mos or all of this species discussed will prove to have wider distributions in the tropics when world-wide revisions are carried out.

A Synopsis of Mitthyridium (Musci: Calymperaceae) in Malaysia and Adjacent Regions

Review of recent and historical specimens of Mitthyridium (Musci: Calymperaceae) from Malaysia, and adjacent regions reveals 12 species. A key, synonymy, diagnostic features, illustrations, and differentiation from similar species are given for these 12 species, together with an index to all names cited. This article concludes our review of Malaysian Calymperaceae that includes up to now a treatment of the genus Calymperes (Reese & Mohamed 1985) and one of Syrrhopodon (Mohamed & Reese 1985). The philosophy of our approach to the study of this family of tropical mosses is discussed in our two earlier publications. Manuel (1981) summarized Mitthyridium for peninsular Malaya and Singapore, and listed six species: M. fasciculatum, M. flavum, M. manii, M. undulatum, M. undulatulum, and M. wallisii. Of these six taxa, we recognize here M. fasciculatum, M. flavum, M. undulatum, and M. wallisii, while we regard M. manii and M. undulatulum as syn- onyms of M. repens. In addition, we also recognize here the presence in Malaysia of M. crassum, M. constrictum, M. jungquilianum, M. luteum, M. sub- luteum, M. cardotii, and M. obtusifolium. The distribution of Mitthyridium is almost ex- clusively in the paleotropics, with only a single his- torical collection of one wide-ranging species re- corded from the western coast of South America (Chile). The genus, as it occurs in Oceania, was re- vised by Nowak (1980), who provided keys, de- scriptions, illustrations, and distribution maps in her extremely valuable treatment. In general, syn- onymy already cited by Nowak and accepted in our study is not repeated here. Mitthyridium, a very natural genus of mosses, seems to be a taxonomically difficult group to study in the sense that it is often difficult to place names, with confidence, on specimens. Surprisingly, in spite of this difficulty, relatively few species have been described for the genus, especially as compared with its sister genera, Calymperes and Syrrhopodon.

Substrate Preference in Calymperaceae: Calymperes, Mitthyridium, and Syrrhopodon

Abstract Substrate preferences of 87 taxa in Calymperes, Mitthyridium, and Syrrhopodon (Calymperaceae), as determined from label data on herbarium specimens, vary at the generic level as well as among the specific and subspecific taxa. The bark of trees and lianas is the most preferred substrate. Mitthyridium is most constant to the bark substrate, followed by Calymperes and then Syrrhopodon. Nineteen taxa of Syrrhopodon (38% of the 50 taxa studied), 14 taxa of Calymperes (50% of the 28 taxa studied), and six taxa of Mitthyridium (67% of the nine taxa studied), were 50 percent or more constant to bark; this trend reflects the presumed direction of evolutionary specialization of the genera. Preference for other substrates varies according to genus: rock is the second most common substrate for Calymperes, and dead wood is second for Mitthyridium and Syrrhopodon. The tree base habitat is also of importance for the three genera. Soil as a substrate is of least importance for Mitthyridium (a sample of one taxon collected on soil), intermediate for Calymperes (samples of 10 taxa: 36% of the 28 taxa), and of greater importance for Syrrhopodon (samples of 30 taxa: 60% of the 50 taxa).

The Gemmae of the Calymperaceae

Abstract Observations of the gemmae of 135 specific and subspecific taxa of Calymperes, Mitthyridium, and Syrrhopodon reveal that the gemmae of most taxa have a generalized morphology. However, the morphologies of some of the gemmae differ among species and species-groups, revealing evolutionary divergence at the levels of genus and subgenus, in which gemmae vary in shape, color, surface texture, appendages, and in average size (from about 75 μm long in S. orientalis to more than 1,600 μm long in S. helicophyllus). Divergence from the generalized gemma morphology reflects the ecological life styles of the taxa, as for example in Syrrhopodon subg. Pseudocalymperes, in which filiform or moniliform gemmae borne in splashcups correlate with the commonly ramicolous habitat.

Gemmipars in the Calymperaceae

Abstract World-wide, 15 taxa (11% of the 137 studied) of the three traditional genera of Calymperaceae (s.s.) regularly produce gemmae sequentially on multicellular stalk-like foliar structures referred to here as gemmipars. Individual gemmiferous leaves give rise to few to many gemmipars, each of which is capable of producing gemmae continuously during the functional life of the leaf. In the remainder of the gemmiferous species of Calymperaceae, the gemmae are produced and matured simultaneously on each gemmiferous leaf, and after abscission of their gemmae the gemmiferous leaves play no further role in asexual reproduction. Syrrhopodon, seemingly the least specialized genus of the family, has only about half the frequency of occurrence of gemmipars (7% of the 82 taxa studied) as that of Calymperes (17% of 35 taxa) and Mitthyridium (15% of 20 taxa). Gemmipars are species-specific in the Calymperaceae and thus potentially useful in systematics. The taxon-limited occurrence of gemmipars in the Calymperaceae and their role in enhancing asexual reproduction suggest that this method of asexual reproduction has ecological and evolutionary implications.