Definition

1. Proper noun (Taxonomic rank): A taxonomic order of fungi within the class Ustilaginomycetes. This order comprises the smut fungi, which are obligate plant pathogens. These fungi are characterized by producing sooty, dark masses of teliospores (chlamydospores) that resemble soot or smut, typically infecting the floral parts, seeds, stems, or leaves of host plants, especially grasses and cereals.

Usage Notes

• Capitalization: As a formal taxonomic name, "Ustilaginales" is always capitalized.
• Context: The term is used almost exclusively in scientific contexts, particularly in mycology (the study of fungi), plant pathology, and agriculture.
• Grammar: It functions as a singular noun when referring to the order as a collective group (e.g., "The order Ustilaginales is widespread.").

Examples of Usage

• Scientific Description:
  • The characteristic life cycle of the order Ustilaginales involves the production of teliospores within the host tissue.
  • Several important cereal diseases are caused by fungi classified under Ustilaginales.
• Taxonomic Context:
  • The smut fungus Ustilago maydis is a well-studied member of the order Ustilaginales.

Advanced Usage

• Phylogenetic Context: In modern fungal taxonomy based on molecular phylogenetics, the classification of smut fungi is under revision. The traditional order Ustilaginales is sometimes considered in a broader sense or subdivided, with some families now placed in other orders like Urocystidales.
  • Molecular data has led to a re-evaluation of the boundaries within the order Ustilaginales.

Variants and Related Words

• Ustilaginaceous (adj.): Of or pertaining to the order Ustilaginales.
  • The ustilaginaceous fungi were observed on the corn plants.
• Smut (n.): The common name for a plant disease caused by fungi of the order Ustilaginales, or for the dark spore mass itself.
  • Corn smut is caused by a member of the Ustilaginales.
• Ustilaginomycetes (n.): The class to which the order Ustilaginales belongs.

Synonyms

• Smut fungi (common name, not a taxonomic synonym)
• Smuts (common name, plural form)

Related Phrases / Terms

• Obligate parasite: A key characteristic of members of the Ustilaginales; they can only grow and reproduce on a living host plant.
• Teliospore / Chlamydospore: The thick-walled, resting spore type diagnostic for fungi in the order Ustilaginales.
• Brand spore: Another term for the dark teliospores produced by these fungi.

Noun

1. parasitic fungi causing smuts; sometimes placed in class Tiliomycetes