Nuclear Large Subunit Ribosomal DNA Research Articles

Phylogenetic Assessment of Understudied Families in Hymenochaetales (Basidiomycota, Fungi)-Reporting Uncovered Species and Reflecting the Recent Taxonomic Updates in the Republic of Korea.

Hymenochaetales Oberw. is an order classified in Basidiomycota of Fungi, and species in this order display notable diversity. They exhibit various fruiting body shapes, including clavarioid, effused-reflexed, and resupinate basidiomes. Few mycorrhizal species have been reported in Hymenochaetales, but wood-decaying species dominate the order. Hymenochaetaceae Imazeki & Toki and Schizoporaceae Jülich are the most species-rich families within Hymenochaetales, and most species in the Republic of Korea belong to these two families. As such, current taxonomic classification and nomenclature are not reflected upon species in the remaining Hymenochaetales families. For this study, a multifaceted morphological and multigenetic marker-based phylogenetic investigation was conducted to, firstly, comprehensively identify understudied Hymenochaetales specimens in Korea and, secondly, reflect the updates on the species classification. Five genetic markers were assessed for the phylogenetic analysis: nuclear small subunit ribosomal DNA (nSSU), internal transcribed spacer (ITS), nuclear large subunit ribosomal DNA (nLSU), RNA polymerase II subunit 2 gene (RPB2), and translation elongation factor 1 gene (TEF1). The results from phylogenetic analysis supported 18 species classified under eight families (excluding Hymenochaetaceae and Schizoporaceae) in Korea. Species formerly placed in Rickenellaceae and Trichaptum sensu lato have been systematically revised based on recent taxonomic reconstructions. In addition, our findings revealed one new species, Rickenella umbelliformis, and identified five formerly nationally unreported species classified under five understudied families. Our findings contribute to a better understanding of Hymenochaetales diversity and highlight the need for continued research.

A new genus and species of Cryphonectriaceae causing stem cankers on plantation eucalypts in South Africa

AbstractFungi in the Cryphonectriaceae are important canker pathogens of woody shrubs and trees in the Melastomataceae and Myrtaceae (Myrtales). During 2021 disease surveys in KwaZulu‐Natal (South Africa) plantations, a serious stem canker disease was discovered on species of Eucalyptus and Corymbia. The cankers had structures on their surfaces typical of fungi in the Cryphonectriaceae. The aims of the study were to identify the fungus associated with the disease and to test its pathogenicity. Morphological characteristics of both sexual and asexual structures and phylogenetic analyses based on partial sequences of the conserved nuclear large subunit (LSU) ribosomal DNA, the internal transcribed spacer (ITS) regions including the 5.8S gene of the ribosomal DNA operon, and two β‐tubulin (BT1/BT2) regions were used for identification purposes. Phylogenetic analyses of the sequence data and morphological characteristics supported the establishment of a new genus in the Cryphonectriaceae, for which the name Xanthoporthe myrticola gen. et sp. nov. is provided. Pathogenicity trials showed that isolates were pathogenic on tested Eucalyptus grandis and hybrids as well as Corymbia henryi. The results suggest that this is an emerging pathogen that could influence the sustainability of plantation forestry in South Africa.

Multi-locus phylogenies revealed a new record of Entoloma species (Basidiomycota, Agaricales) responsible for gastrointestinal poisoning

The frequency of mushroom poisoning has increased worldwide. In Thailand, reports on mycetism between 2013 and 2021 included 18 cases of Entoloma poisoning. Incorrect identification of toxic Entoloma species occurs during wild mushroom foraging, and their consumption results in gastrointestinal irritation. Morphological distinction of mushroom leftovers is difficult; however, we aimed to characterize 40 clinical samples to the genus level using macroscopic and microscopic analyses. Furthermore, species identification of the poisonous Entoloma was performed based on multi-locus phylogenetic analyses of the nuclear internal transcribed spacer region, nuclear large subunit ribosomal DNA, and mitochondrial small subunit ribosomal DNA. Phylogenetic trees reconstructed using maximum likelihood and Bayesian methods demonstrated that forty samples of mushroom remnants formed eight robust clades with six identified species. The findings confirmed the taxonomic identity of E. griseolazulinum as a new record of species causing gastrointestinal poisoning. The use of molecular annotation provided a foundation for the development of accurate methods for identification of toxic mushrooms.

First report of Calonectria pseudopteridis causing brown spot on Eriocaulon buergerianum in Zhejiang province, China.

Eriocaulon buergerianum is a traditional Chinese herb, used to treat eye diseases. In July 2020, a severe brown spot disease occurred on E. buergerianuim in Yongjia county (120°19'E, 27°58'N), Zhejiang province, China. Seventy-three plants from a survey of about 150 plants showed brown leaf spots. The spots were yellowish-brown to brown, and primarily affected leaves. As the disease progressed, the spots expanded, and fused. Sixty of the 150 plants wilted (Fig. 1 A-D). Diseased tissues were surface-sterilized in 75% ethanol (30 s), rinsed three times with sterile distilled water, air-dried (5 min), placed on potato dextrose agar (PDA) at 26°C (12-h light/dark cycle), and cultured for 4 days. Hyphal tip technique was used to obtain five isolates, which were transferred to malt extract agar (MEA), oatmeal agar (OA), and PDA. After seven days of growth at 26°C, the colonies had light, yellowish-brown centers with gray-white edges; the reverse sides had reddish- to yellowish-brown centers. Seven-day-old colonies grown on oatmeal agar (OA) produced a sparse aerial mycelium with yellowish-brown centers, and light yellowish-brown centers on the reverse side. Seven-day-old colonies grown on PDA exhibited yellowish-brown, floccose, aerial mycelia with reddish-brown to yellowish-brown pigment on the back (Fig. 1 E-G). The colonies also produced microsclerotia on OA and PDA media. On carnation leaf agar (CLA) and water agar (WA), only macroconidia were produced. Macroconidiophores comprised a stipe bearing penicillate, fertile branches, and a clavate vesicle. Macroconidia were cylindrical, rounded at both ends, colorless, hyaline, 1- to 2-septate, but mainly one, and 71.86 to 96.11 µm (mean = 82.27 µm, n = 50) × 4.13 to 5.21 µm (mean = 4.63 µm, n = 50) (Fig. 1 H-K). Morphological characteristics of the isolate on CLA or WA medium were similar to the Calonectria petridis species complex (Alfenas et al. 2015; Liu et al. 2020). The actin (Act), calmodulin (Cal), internal transcribed spacer (ITS), Histone3 (His3), a fragment of the large subunit nuclear ribosomal DNA (LSU), RNA polymerase II subunit 2 (Rpb2), translation elongation factor 1α (Tef1), and β-tubulin 2 (Tub2) genes were sequenced. The sequences were deposited in GenBank as: His3: Not detected; Act, OM933603, MZ770831, OM933604-OM933606; Cal, OM933607, MZ770832, OM933608-OM933610; ITS, OM955624, MZ720794, OM955625-OM955627; LSU, OM955640, MZ720792, OM955641-OM955643; Rpb2, OM933615, MZ770834, OM933616-OM933618; Tef1, OM933611, MZ770833, OM933612-OM933614; and Tub2, OM933619, MZ770835, OM933620-OM933622. Sequences of the Act, Cal, ITS, LSU, Rpb2, and Tef1 genes of these strains show a 99% match to the ex-type strain Ca. pteridis CBS111793 and Ca. pseudopteridis CBS163.28 (Act, GQ280494, MT335112; Cal, GQ267413, MT335347; ITS, GQ280616, MT359808; LSU, GQ280738, MT359568; Rpb2, KY653438, MT412640; Tef1, FJ918563, MT412878). The Tub2 sequences showed 99% identity with sequences of the ex-holotype Ca. pteridis CBS111793 (Tub2, DQ190578) (Alfenas et al. 2015; Liu et al. 2020; Lombard et al. 2016). Phylogenetic analysis showed that these strains and Ca. pseudopteridis CBS163.28 were clustered in a high-support bootstrap value clade (bootstrap = 85) (Fig. 2). In August 2020, healthy E. buergerianum plants in the blooming-fruiting stage were used to test the pathogenicity of the isolates. The mycelium of isolate GJC3 was cultured on CLA medium at 26°C (12-h light/dark cycle) for ten days. Eight healthy plants were inoculated by spraying with a conidial suspension (10 mL of 1 × 105 conidia/mL). Another eight plants were sprayed with sterilized water 10 mL of sterilized water as controls. The experiment was repeated three times. Pathogenicity tests were performed in the greenhouse (60% relative humidity, 28 to 20°C day/night, temperature range, and natural sunlight). After 15 days, inoculated plants showed yellowish-brown to brown spots and withering of the leaves, whereas the control plants remained healthy (Fig. 1 L-N). Ca. pseudopteridis was reisolated from the inoculated plants, and its morphology and gene sequences were similar to the original isolate GJC3. Ca. pseudopteridis was not isolated from the control plants. Morphological characteristics, molecular data and pathogenicity test identified these organisms as Ca. pseudopteridis. This report provides a basis for further research on biology and management of this disease.

Four new additions to Helvella (Helvellaceae, Pezizales) from Northern Thailand.

Most species of Helvella have been described from temperate regions in Asia, Europe, and North America, but little is known about the genus from tropical regions. In this report, phylogenetic analyses of 11 newly collected saddle-like fungi from northern Thailand using three genetic markers [the nuclear large subunit ribosomal DNA (LSU), the heat shock protein 90 (HSP90), and the translation elongation factor 1-alpha (TEF)] confirm their assignment in Helvella. Two species were described as new, i.e., Helvella atroides and H. orentitomentosa, and two species, i.e., H. fistulosa and H. rugosa, were reported for the first time in Thailand. Details of macro- and microscopic characters and illustrations were provided for each species. To date, seven species of Helvella have been recorded in Thailand, and a key for identifying the Thai Helvella species was provided here.

Exploring More on Dictyosporiaceae: The Species Geographical Distribution and Intriguing Novel Additions from Plant Litter

Five fungal taxa collected from plant litter in Chiang Mai province, Thailand, are described with illustrations. The maximum likelihood, maximum parsimony, and Bayesian analyses of combined loci of the internal transcribed spacer (ITS), large subunit nuclear ribosomal DNA (LSU), and translation extension factor 1-α (tef1-α) region were used for phylogeny analyses. Dictyocheirospora acaciae is introduced as a new species from Acacia dealbata. Based on size differences in conidiomata, conidia, and DNA sequence data, it is separated from the other species in the genus. Four new host records, Dictyocheirospora garethjonesii, Di. taiwanense, Dictyosporium digitatum, and Pseudocoleophoma zingiberacearum are also reported from Bismarkia nobilis, Ficus benjamina, Cyperus aggregatus, and Hedychium spicatum, respectively. Detailed descriptions, microphotographs, and phylogenetic information were provided, and all the species were compared to similar taxa. It is noted that there is still a necessity for a collective worldwide account of the distribution of Dictyosporiaceae species. Therefore, we compiled the geographical distributions and host species associations of all the so far known Dictyosporiaceae species and discussed them here.

Morphological and molecular studies of a rare mucoralean species causing flower rot in Hylocereus polyrhizus

AbstractThe order Mucorales typically includes fast‐growing saprotrophic and plant pathogenic fungi. Flower rot of red‐fleshed dragon fruit (Hylocereus polyrhizus) caused by Mucor‐like fungi was observed in a field in Phatthalung province, southern Thailand. Agglomeration of sporangiophores and sporangia on the wet rotten tissues of the red‐fleshed dragon fruit flower was detected. Fungal isolates obtained from symptomatic tissues were cultured on potato dextrose agar for macroscopic and microscopic observations. Based on the growth rate and morphology of sporangia and sporangiospores, the fungus was identified as Gilbertella persicaria, which was further confirmed using phylogenetic analyses of the internal transcribed spacer and nuclear large subunit ribosomal DNA sequences. Pathogenicity tests revealed that the fungal isolate G. persicaria caused flower rot, similar to that observed in the field. This study is the first report of flower rot disease in H. polyrhizus caused by G. persicaria in Thailand.

Description of Lepiotaceous Fungal Species of the Genera Chlorophyllum, Clarkeinda, Macrolepiota, Pseudolepiota, and Xanthagaricus, from Laos and Thailand

In our ongoing research on lepiotaceous taxa (Agaricaceae s.l.) in Laos and northern Thailand, we focus here on Chlorophyllum, Clarkeinda, Macrolepiota, Pseudolepiota, and Xanthagaricus. Collections were obtained from various habitats, including agricultural habitats, grasslands, and rainforests. A total of 12 taxa were examined and investigated. Of these 12, two are new for science; viz. Xanthagaricus purpureosquamulosus with brownish-grey to violet-brown squamules on a pale-violet to violet background; it shares the pileus color with X. caeruleus and X. ianthinus, but differs in other characters; and Macrolepiota excelsa, rather similar to M. procera but related to M. detersa. Two species, Pseudolepiotazangmui and Xanthagaricus necopinatus are recorded for the first time in Thailand. Four species of Chlorophyllum and a total of four species of Macrolepiota were found, viz., C. demangei and C. hortense with white basidiospores, C. molybdites and C. globosum with green basidiospores, M. detersa, M. dolichaula, the new M. excelsa, and M. velosa. Another rather common striking species is Clarkeinda trachodes, with yellow-green basidiospores. Each species is described in detail, with color photographs and line drawings. Phylogenetic analyses based on internal transcribed spacer (nrITS) region, the large subunit nuclear ribosomal (nrLSU) DNA and RNA polymerase II second largest subunit (rpb2) genes provide evidence for the placement of the species covered.

Cryptomonas indica sp. nov. (Cryptophyceae: Cryptomonadales), a new species described from the Western Ghats, India

A new species, Cryptomonas indica sp. nov., is described from Western Ghats, India, based on morphological and molecular data. Phylogenetic relationships inferred from nuclear small and large subunit ribosomal DNA, internal transcribed spacer 2, and plastid psbA sequences show that the new species forms a separate lineage on the phylogenetic tree of the genus Cryptomonas. This new species is included in the basal clade of Cryptomonas tree, which consists of undescribed taxa from Europe and South Korea. Cells of this species are up to 19 µm in length, elliptical to slightly asymmetrical in broad view, and have a plastid with four pyrenoids. Cryptomonas indica has been observed in one locality, the Northern region of the Western Ghats. Notably, this is the first Cryptomonas taxon described from the Indian subcontinent with both morphology and molecular information.

Fulvifomes nonggangensis and F. tubogeneratus (Hymenochaetales, Basidiomycota): Two New Species from Southern China Based on Morphological and Molecular Evidences

Two new species of Fulvifomes are described from specimens collected in rainforests of Nonggang Nature Reserve of southern China, based on morphological characteristics and molecular phylogenetic analysis of the internal transcribed spacer (ITS) and nuclear large subunit ribosomal DNA (nLSU) sequences. Fulvifomes nonggangensis sp. nov. is characterized by perennial, sessile and solitary basidiocarps, applanate pileus, small cystidioles of 9.9–15.4 × 2.9–3.5 μm, large pores of 5–6 per mm, a dimitic hyphal system, and broadly ellipsoid basidiospores of 4.3–5.3 × 3.3–4.2 μm. F. tubogeneratus sp. nov. is characterized by perennial, sessile, and imbricate basidiocarps, a duplex context, small pores of 7–8 per mm, a dimitic hyphal system, and ovoid to subglobose basidiospores of 5.72 × 5.00 μm.

Trichinella pseudospiralis in a red kite (Milvus milvus) from Italy.

Trichinella pseudospiralis is a non-encapsulated species infecting both mammals and birds. In Italy, this species has been reported so far only in central regions (two nocturnal birds of prey, one red fox, and one wild boar) and in northeast regions (four wild boars). In November 2020, Trichinella sp. larvae were isolated by enzymatic digestion from muscle tissues of a red kite (Milvus milvus) specimen belonging to a population residing in the Basilicata region (Southern Italy). The parasite was identified as T. pseudospiralis by multiplex PCR, and the sequencing of the expansion segment V (ESV) region of the nuclear large subunit ribosomal DNA showed, in the microsatellite region, the polymorphism characteristic of the Palearctic population. This represents the first record of T. pseudospiralis in a red kite and the first report of this parasite in Southern Italy. The isolation of the parasite in a resident bird confirms that T. pseudospiralis is present, even if at low prevalence, in the Italian avifauna.

Asperosporus subterraneus, a new genus and species of sequestrate Agaricaceae found in Florida nursery production.

We describe a novel sequestrate genus and species, Asperosporus subterraneus gen. et sp. nov., found associated with nursery production of ferns in south Florida. This truffle species has a unique combination of morphological characters among described Agaricaceae in that it lacks a stipe or columella, has large, ornamented spores, the fresh sporocarps rapidly stain pink-red when cut or bruised, and they have a rancid smell. Although this fungus does not appear to be a direct plant pathogen, the hyphae of A. subterraneus produce a thick hydrophobic mycelial mat that binds the organic matter and therefore prevents water and fertilizer from being absorbed by plants, consequently causing wilting and chlorosis. Using morphological characteristics and phylogenetic reconstruction based on the internal transcribed spacer (ITS), partial large subunit nuclear ribosomal DNA (LSU), second largest subunit of RNA polymerase II (rpb2) and translation elongation factor 1-alpha (tef1) regions, we describe this taxon as a new genus and species in Agaricaceae.

Bambusicolous Arthrinium Species in Guangdong Province, China.

A survey of bambusicolous fungi in Bijiashan Mountain Park, Shenzhen, Guangdong Province, China, revealed several Arthrinium-like taxa from dead sheaths, twigs, and clumps of Bambusa species. Phylogenetic relationships were investigated based on morphology and combined analyses of the internal transcribed spacer region (ITS), large subunit nuclear ribosomal DNA (LSU), beta tubulin (β-tubulin), and translation elongation factor 1-alpha (tef 1-α) gene sequences. Based on morphological characteristics and phylogenetic data, Arthrinium acutiapicum sp. nov. and Arthrinium pseudorasikravindrae sp. nov. are introduced herein with descriptions and illustrations. Additionally, two new locality records of Arthrinium bambusae and Arthrinium guizhouense are described and illustrated.

Taxonomic studies of Cryptomonas lundii clade (Cryptophyta: Cryptophyceae) with description of a new species from Vietnam

A new species from Vietnam, Cryptomonas vietnamica sp. nov., is described based on morphological and molecular data. Six strains from different habitats were analyzed. Cryptomonas vietnamica is characterized by large cells up to 54 µm long, 30 µm wide and 20 µm thick, flattened in dorso-ventral plane and often twisted. Phylogenetic relationships inferred from nuclear small and large subunit ribosomal DNA sequences show that the new species forms a clade with Cryptomonas lundii, a rare taxon, described from Europe. Cryptomonas lundii is reported for the first time from Russia and second time since its initial description.

<p><strong>Two new species of <em>Phaeosaccardinula</em> from Southwest China</strong></p>

Two new fungal species, Phaeosaccardinula dalbergiae and Phaeosaccardinula yunnanensis collected from Yunnan Province, China are described based on morphology and molecular data. They are compared with related taxa of Phaeosaccardinula. Detailed description, illustrations and notes are provided for each species. Molecular analysis based on the phylogenetic tree of combined internal transcribed spacer and large subunit nuclear ribosomal DNA sequences show that the two species form distinct clusters within the genus Phaeosaccardinula.

<p><strong><em>Cryptomonas cattiensis</em></strong><strong> <em>sp. nov.</em> (Cryptophyceae: Cryptomonadales), a new species described from Vietnam</strong></p>

A new species, Cryptomonas cattiensis sp. nov., is described from Vietnam based on morphological and molecular data. Phylogenetic relationships inferred from nuclear small and large subunit ribosomal DNA, internal transcribed spacer 2, and plastid psbA sequences show that the new species forms a separate branch on the phylogenetic tree of the genus Cryptomonas. This species has slightly sigmoid to elliptical cells in ventral view and a single plastid, deeply notched into several irregular lobes, with two pyrenoids. C. cattiensis has been observed in one locality in Cat Tien National Park.

A 28S rDNA‐based phylogeny of the nematode family Acuariidae (Spirurida) parasitic in vertebrates

AbstractThe aim of this study was to investigate the phylogenetic relationships of nematodes of the family Acuariidae using partial large subunit nuclear ribosomal DNA (28S) sequences of 15 genera represented by 18 species. The results confirmed the monophyly of the family Acuariidae and supported its close relationship with nematodes of the family Cystidicolidae. Two major clades were revealed within Acuariidae, one represented by nematodes of the subfamily Schistorophinae and another composed of members of the subfamilies Acuariinae and Seuratiinae. The collarette was shown to be a structure that arose several times within the clade Acuariinae–Seuratiinae. As a result, we suggest the suppression of the subfamily Seuratiinae and inclusion of its genera within the subfamily Acuariinae. Morphological characters, host ranges and life cycles of the taxa included in the analyses are discussed as well as the possible relationships of remaining acuariid genera within the revealed subclades. Additionally, we propose an amended generic diagnosis of Syncuaria Gilbert, 1927 to accommodate Syncuaria sagittata (Rudolphi, 1809) n. comb. and Syncuaria longevaginata (Molin, 1860) Skrjabin, Sobolev, & Ivashkin, 1965. New host and geographic records are also presented.

A new species and emendation of the seldom reported Enterohaematotrema Mehra, 1940 (Digenea: Schistosomatoidea), including a revised phylogenetic hypothesis for turtle blood flukes.

Enterohaematotrema Mehra, 1940 is emended herein based upon a review of the literature and a description of a new species (Enterohaematotrema triettruongi n. sp.) infecting yellow-headed temple turtles, Heosemys annandalii (Boulenger) (Cryptodira: Geoemydidae), in the Mekong River, Vietnam. The new species differs from the published descriptions of its congeners Enterohaematotrema palaeorticum Mehra, 1940 and Enterohaematotrema hepaticum (Simha, 1958) Simha & Chattopadhyaya, 1980 by having two distinctive oesophageal glands, a short and eversible cirrus (vs protrusive with 3 distinct processes), a dorsal common genital pore that is sinistral (vs ventral and medial), a transverse (vs longitudinal) external seminal vesicle, an oviducal seminal receptacle that is sinistral (vs dextral), and a vitellarium distributing from the caecal bifurcation (anterior to the ventral sucker) to the caecal tips (vs vitellarium not extending anteriad beyond ventral sucker in E. palaeorticum or vitellarium wholly posterior to the terminal genitalia in E. hepaticum). A phylogenetic analysis of the D1-D3 domains of the nuclear large subunit ribosomal DNA (28S) recovered Enterohaematotrema and Platt Roberts & Bullard, 2016 as sister taxa that share a recent common ancestor with the clade comprising Ruavermis Dutton & Bullard, 2020 and Coeuritrema Mehra, 1933. These flukes collectively comprise a monophyletic group of southeast Asian turtle blood flukes. This analysis also indicated that the massive, longitudinal metraterm of species of Enterohaematotrema and Uterotrema Platt & Pichelin, 1994 represents homoplasy (convergent evolution). The present study comprises the first morphological study of original specimens of any species of Enterohematotrema in more than 50 years and is the first molecular phylogenetic placement of the genus among the various turtle blood fluke lineages.

The genera Helvella and Dissingia (Ascomycota: Pezizomycetes) in Europe - Notes on species from Spain.

Phylogenetic analyses of 115 newly collected Helvella specimens from Spain using three genetic markers [heat shock protein 90 (hsp), RNA polymerase II second largest subunit (rpb2) and the nuclear large subunit ribosomal DNA (LSU)] confirm the assignment of the Spanish collections to one Dissingia and 30 Helvella species. The analyses were supplemented with an additional sample of 65 Spanish and extralimital Helvella specimens from the fungaria of Oslo (O), Trondheim (TRH), Copenhagen (C), Uppsala (UPS), Stockholm (S) and Venice (MCVE). Nine species are described as new, i.e. Helvella fuscolacunosa, H. hispanica, H. iberica, H. inexpectata, H. neopallescens, H. phlebophoroides, H. poculiformis, H. retinervis, and H. terricola. We present photographs of a selection of fresh specimens and provide descriptions of all species of this diverse South European Mediterranean element of the genera in Europe.

Milesina thailandica, a second rust fungus on an early diverged leptosporangiate fern genus, Lygodium, found in Thailand

A new rust fungus was found on Lygodium flexuosum at Doi Suthep-Pui National Park in Chiang Mai Province, Thailand. Puccinia lygodii was the only rust fungus currently known on Lygodium spp. (Lygodioideae, Schizaeaceae, Schizaeales) from southern North America through northern South America. The new fungus produced uredinia linearly between veins, causing yellowish streaks, on the abaxial frond surface. The sori were covered with a layer of thin-walled fungal cells beneath the host epidermis and surrounded by thin-walled paraphyses. The sori did not have a distinct central aperture with ostiolar cells but ruptured irregularly to release urediniospores. Urediniospores were obovoid, obovoid-ellipsoid, or pyriform. The wall was thin, colorless, and completely echinulate. Neither amphispores nor teliospores were observed. The sorus and spore morphology indicated the taxonomic affinity of the fungus to the fern rust genera Hyalopsora and Milesina. A molecular phylogenetic analysis using nuclear large subunit ribosomal DNA sequence revealed that the Lygodium rust fungus was grouped in a paraphyletic Milesina clade. From the putative host preference, morphology, and estimated phylogenetic relationships, it was concluded that the fungus was a new species of Milesina.