Endophytic fungi are symptomless internal inhabits of plant tissues. They are implicated in the production of antibiotic and other compounds of therapeutic importance. Ecologically they provide several benefits to plants, including protection from plant pathogens. There have been numerous studies on the biodiversity and ecology of endophytic fungi. Some taxa dominate and occur frequently when compared to others due to adaptations or capabilities to produce different primary and secondary metabolites. It is therefore of interest to examine different fungal species and major taxonomic groups to which these fungi belong for bioactive compound production. In the present paper a list of endophytes based on the available literature is reported. More than 800 genera have been reported worldwide. Dominant genera are Alternaria, Aspergillus, Colletotrichum, Fusarium, Penicillium, and Phoma. Most endophyte studies have been on angiosperms followed by gymnosperms. Among the different substrates, leaf endophytes have been studied and analyzed in more detail when compared to other parts. Most investigations are from Asian countries such as China, India, European countries such as Germany, Spain and the UK in addition to major contributions from Brazil and the USA.

Fungi inhabiting the aerial parts of two mangrove trees, Nypa fruticans, and Rhizophora apiculata, were studied from the central region of Thailand, utilizing morpho-molecular characteristics. Three different fungal taxa were isolated including Rhytidhysteron kirshnacephalus sp. nov., Lasiodiplodia citricola and Striatiguttula phoenicis. Sexual morphs are reported for these three taxa and the asexual morph of Striatiguttula phoenicis is identified based on molecular data. This is the first asexual morph report for the genus Striatiguttula as well as the family Striatiguttulaceae. The new isolate of Striatiguttula phoenicis differs slightly from other extant species in the genus in terms of measurements of ascomata, asci, ascospores, and thickness of peridium. Also, a pigmented hamathecium was observed in this species. The morphological results are congruent to the phylogenetic results of previous studies and support Striatiguttula phoenicis as a new host record from Nypa fruticans. Rhytidhysteron kirshnacephalus was collected from dead twigs of a standing Rhizophora apiculata in Cha-am and it has significant morphological and molecular differences to support its establishment as a novel taxon. Phylogenetically, Rhytidhysteron kirshnacephalus forms a sister clade to Rh. magnoliae, but has different ascomatal characters, including, smooth margins without striations and black pruina. Lasiodiplodia citricola is another species from Cha-am and a new record from Thai mangroves. Detailed descriptions of the isolates, along with their potential ecological roles, are provided. We have also provided the occurrence of fungi from the aerial parts of mangrove trees worldwide.