Hemitrichia is a genus of slime molds, of the family Trichiaceae, found within the order Trichiida. It was first described by Josef Rostafinski in 1873 and remains a well-defined genus of the slime molds. Hemitrichia species exhibit either plasmodiocarp or sporangium fruiting bodies, both of which are well-known and recognizable slime molds seen on multiple continents. This genus includes species such as H. serpula (known as the pretzel slime mold) and H. decipiens (known as salmon-eggs), both of which are widespread.
Etymology
Hemi comes directly from the Greek prefix hemi, meaning “half”. Trichia is combination of the Greek trichios, which refers to hair or hair-like structure and –ia, referring to a condition, leading to –trichia being the condition of having hair. Hemitrichia therefore refers to the condition of partially having hair.
Josef Rostafinski described Hemitrichia in the family Trichiaceae, along with another genera Trichia. Trichia was described as having numerous capillitium threads, which are free and tapered at the ends. Hemitrichia is described as having capillitium threads that can either be free or fused into a net.
History of knowledge
H. serpula, in France
As in all members of the Trichiida order, the structure of the capillitium plays a major role in identifying and defining the different families and genera. The presence of a net-like capillitium is likely the most defining and recognizable feature of the genus Hemitrichia, as it has been mentioned by almost every author in his or her description of the genus. It was first described by Josef Rostafinski in his 1873 book “Versuch eines systems der mycetozoan”. Rostafinski places Hemitrichia as one of two genera under the family “Trichiaceae”, the other being Trichia. Rostafinski describes the genus as having “apillitium tubes fused into nets, free or with single tapered ends trapped between stalk contents”. The genus has also previously been referred to as “Hemiarcyria” by Fries...
