George Yatskievych

A previously unrecognized interspecific hybrid in the fern genus Polypodium is described from collections made at a single remote locality in central Arizona. Originally identified as P. glycyrrhiza, this sterile nothotaxon is easily distinguished from other members of the genus and is here named Polypodium xaztecum Windham & Yatsk. The hybrid is tetraploid, exhib- iting ca 37 bivalents and 74 univalents at diakinesis. Based on geographic proximity and shared morphological traits, we conclude that P. hesperium is one of the parents of the new taxon. Assuming that the hybrid is more or less intermediate between P. hesperium and a second parental taxon, we attempt to identify the missing parent. The most likely candidate is P. calirhiza, a species of Oregon, California, and Mexico that has not been documented from Arizona. However, we cannot rule out the possibility that the missing parent is an as yet unidentified member of the P. plesiosorum complex from Mexico.

Seven species of the genus Baccharis have been analyzed for flavonoid aglycones. Many known methylated flavones, flavonols and flavanones were identified. From B. sarothroides, two novel flavonols were isolated and elucidated as 5,7,4′-trihydroxy-3,6,8-trimethoxyflavone and its methyl ether, 5,4′-dihydroxy-3,6,7,8-tetramethoxyflavone. Previous literature reports on flavonoids in Baccharis are summarized and their distribution and external occurrence is discussed. One novel diterpene and one rare triterpene were found in the terpenoid fractions that constitute most of the exudate material in these and other Compositae.

Eriodictyon sessilifolium, an endemic Hydrophyllaceae of Baja California (Mexico), has been studied for the natural products exuded by glandular trichomes covering its leaves and stems. Major components of this exudate were isolated and identified by spectroscopic methods to be 4-hydroxy-3-(2,3-dihydroxy-3-methylbutyl)-benzoic acid methyl ester (1), the natural methyl ester of anodendroic acid (2), and 2,2-dimethyl-3-hydroxychroman-6-carboxylic acid methyl ester (3). Possible biosynthetic relations between these new natural products are considered. In addition, 9 known flavonoid aglycones were identified as exudate constituents.

Restriction site variation in chloroplast DNA was examined in the neotropical fern genus Phanerophlebia and in selected species of the related Asiatic genus Cyrtomium and the cosmopolitan progenitor of these two, Polystichum . A total of 103 restriction site mutations was identified; these were used to construct phylogenetic networks and trees based on Wagner and Dollo parsimony and Fitch-Margoliash distance algorithms. The analyses provided evidence that Phanerophlebia did not arise from Cyrtomium . Both genera are convergent descendants from different progenitor groups in Polystichum , and Asiatic Cyrtomium is more closely related to temperate New World Polystichum than it is to neotropical Phanerophlebia . Reticulate venation, previously considered an important taxonomic character for infrageneric classification in Phanerophlebia , most likely evolved independently twice within the genus. Diploid maternal progenitors are suggested for two of four tetraploid species analyzed, and ...

... 100 DIANA B. STEIN, GEORGE YATSKIEVYCH AND GERALD J. GASTONY Phanerophlebia juglandifolia (2X) 0.34 juglandifolia I Ll( 0.02 re6ora 02z rl '1 pumila 0.17 t umbonata 0.27 I Ioo71 nobili9 0091 I remotispora o08J auriculata I'0 ... Zurawski, G. and Clegg, MT (1987) Ann. ...

The cheilanthoid ferns have long resisted efforts to circumscribe well-defined, phylogenetically natural generic and infrageneric groups, presumably because of homoplastic morphologies associated with their xeric habitats. This cladistic analysis of phylogenetically informative chloroplast DNA restriction site data from 14 enzymes and seven taxa in the cheilanthoid genus Pellaea provides new insights into the phylogenetic relationships of the P. glabella complex. It also assesses the congruence of results based on restriction site data at inter- and intraspecific levels in these sexually and apogamously reproducing ferns with those of earlier morphological and isozyme analyses of the same group. Wagner parsimony yielded a single most parsimonious tree of 187 steps and 11% homoplasy, based on a data matrix of 166 restriction sites of which 66 were phylogenetically informative. Phylogenetic analysis based on user-defined stepmatrix character-state weighting of site gains over losses produced an identical single most parsimonious tree. Dollo parsimony yielded two most parsimonious trees, one of which was topologically identical to the Wagner tree. Specific and infraspecific relationships in the P. glabella complex determined by the completely independent restriction site and isozyme data sets are identical. This lends confidence to the ongoing use of restriction site data in a broader study of Pellaea and other cheilanthoid taxa and to the present conclusions that P. atropurpurea is sister to the P. glabella complex, whereas P. breweri, previously considered the closest relative of this complex, is actually more distantly related to it than are the other taxa in this study.

The silverback and goldback ferns of the genus Pityrogramma Link are striking, graceful plants of small to medium size, well known to fern fanciers for their beautiful white to yellow farinose indument. Tryon & Tryon (1982) classified the group in the tribe Taenitideae of their broadly circumscribed Pteridaceae Reichb. (= Adiantaceae (C. Presl) Ching; see Pichi Sermolli, 1986) and the taxa were last revised taxonomically by Tryon (1962), who recognized 14 species. Among the goldback and silverback ferns, the complex of species indigenous to the southwestern United States and adjacent Mexico has excited the greatest controversy, both with respect to species number and affinities of the group. Tryon (1962) followed Weatherby's (1920) disposition of the taxa as four varieties of a single species, P. triangularis (Kaulf.) Maxon. Alt & Grant (1960), however, recognized three distinct species based on Weatherby's varieties, P. pallida (Weath.) K. & V. Grant, P. viscosa (D. Eaton) Maxon, and P. triangularis (with only two varieties). The California Flora (Munz & Keck, 1968) followed the single species scheme in the general text, but recognized three species in the supplement, and also included mention of two other varieties of P. triangularis described since the work of Alt & Grant (1960). At the generic level there has been growing recognition that the southwestern complex is anomalous within Pityrogramma. Tryon (1962) pointed out that this group departs in several morphological characters from the relatively uniform "central group" of species in the genus and suggested that this specialized relative of Pityrogramma proper might merit generic recognition. He chose to treat the taxa as a single genus, however, to emphasize the similarities (rather than the differences) between the groups. More recently, Tryon & Tryon (1982) suggested that the southwestern complex might be better classified in the tribe Cheilantheae rather than the tribe Taenitideae, but postponed formal taxonomic segregation from Pityrogramma until the group's affinities became better known. During studies leading to treatments for the genus Pityrogramma for the Flora of North America Project and the Ferns and Fern Allies of the Southwestern United States (Windham & Yatskievych, in prep.) we also concluded that the P. triangularis complex should be segregated from Pityrogramma. This paper is intended to review the rationale for distinguishing these two morphologically

Summary Five species of Ambrosia (Compositae) from Arizona were examined for the accumulation of flavonoid aglycones in the resinous covering on their leaves and stems. A series of flavones and flavonols as well as some flavanones were identified by direct comparisons and by spectral studies. 6-Methoxy derivatives, including the rare products 3'-demethoxysudachitin, xanthomicrol, sideritiflavone, and oxyayanin-B, dominated the flavonoid content of the resin. The various flavonoid patterns observed in this study may be species-specific. Further work on such variations should include studies of populations as well as of additional species.

ABSTRACT Originally published in 1963, the late Julian Steyermark’s Flora of Missouri has been the principal reference on plant life in the state. It also has been used widely in surrounding regions and has served as a model for floristic manuals in the United States. Although out of print and in serious need of revision, it has continued to be an essential tool for land managers, conservationists, ecologists, taxonomists, foresters, wildlife biologists, and other students of Missouri’s diverse flora. In 1987, in recognition of the need for an up-to-date reference on the state’s flora, the Missouri Department of Conservation and the Missouri Botanical Garden entered into an agreement to jointly sponsor the production of a thoroughly revised manual. The first volume of the greatly expanded new edition was published in 1999. The present volume is the final of three that are intended to fulfill this promise. Steyermark’s Flora of Missouri is an account of Missouri’s vascular flora, including the pteridophytes, gymnosperms, and flowering plants growing spontaneously in the state. Volume Three contains treatments of 1031 species in 343 genera in the dicot families Fabaceae through Zygophyllaceae (alphabetical sequence). Users of the previous edition will note similarities in format, with keys to families, genera, species, and infraspecific taxa, full-page plates of line drawings, and county dot maps for each species. However, the revised edition features all-new illustrations and simplified maps generated from a computerized database of specimens. The keys have been streamlined and morphological descriptions have been added to the text. Taxonomic changes and additions are documented in a lengthy bibliography and a glossary defines technical terms used in the text.

Page 1. A REVISION OF THE FERN George Yatskievych2 GENUS PHANEROPHLEBIA (DRYOPTERIDACEAE)' ABSTRACT The primarily neotropical fern genus Phanerophlebia is revised taxonomically to include eight species, with a key and descriptions provided. ...

Perennial herbs with branched rhizomes. RHIZOMES deep-seated, often dark brown to purplish black, usually with nodal sheathes similar to the aerial stems, these becoming degraded with age. ROOTS adventitious, often branched. AERIAL STEMS unbranched or with whorls of branches, sometimes irregularly branched following flood damage, hollow (except at nodes), with a larger central longitudinal canal and 2 rings of smaller canals, those under the ridges (carinal canals) and those between the ridges (vallecular canals). the nodes jointed. LEAVES whorled, fused into short sheaths at the stem nodes, the tooth-like free tips brown to black, concolorous or bicolorous with a green to white midvein or white margins, persistent or shed early. STROBILI cone-like, with peltate sporophylls, borne at the stem and/or branch tips, green or the sporangiophores sometimes brownish-to blackish-tinged, the strobilus tip rounded or sharply mucronate. SPORANGIA in a ring of 5-10 along the undersurface of spo...

... Dahlgren et al. ... style single; stigma capitate, entire or slightly 5-9-lobate; placentation axile, but appearing free-central in fruit; fruit a slightly depressed capsule, somewhat fleshy, but drying at maturity; dehiscence circumscis-sile by an irregular ring below middle of cap-sule (fig. ...