Sphenophytes are represented today by one genus, Equisetum. This is the last remaining sphenophyte genus, a relict from a group which was far more diverse and abundant during the Palaeozoic Era. These plants are commonly referred to as ‘horsetails’, due to the appearance of their whorls of tufty leaves, or ‘scouring rushes’, since they have been used since pre-history to scour dirty dishes because of their high silica content. Making their first appearance in the Devonian, horsetails are today considered 'living fossils'.
Rinistachya hilleri
Locality: Waterloo Farm
Age: latest Devonian
This species is a rare example of a Devonian sphenophyte. It has some primitive characters, retaining features that support decent of sphenophytes from an iridopteridalean ancestor, and adding useful new information about this debated relationship (1).
Rinistachya has characteristic webbed leaves borne in whorls at nodes along the axis, and bears its fertile parts in loose whorls. The fertile appendages are multiply branched, much like the iridopteridaleans.
This species is the only known sphenophyte from the Devonian of Gondwana, and makes a valuable addition to the known diversity of plants of that age.
Locality: Waterloo Farm
Age: latest Devonian
This species is a rare example of a Devonian sphenophyte. It has some primitive characters, retaining features that support decent of sphenophytes from an iridopteridalean ancestor, and adding useful new information about this debated relationship (1).
Rinistachya has characteristic webbed leaves borne in whorls at nodes along the axis, and bears its fertile parts in loose whorls. The fertile appendages are multiply branched, much like the iridopteridaleans.
This species is the only known sphenophyte from the Devonian of Gondwana, and makes a valuable addition to the known diversity of plants of that age.
References:
1) Prestianni, C., & Gess, R. W. (2019). Rinistachya hilleri gen. et sp. nov. (Sphenophyllales), from the upper Devonian of South Africa. Organisms Diversity & Evolution, 19(1), 1-11.
1) Prestianni, C., & Gess, R. W. (2019). Rinistachya hilleri gen. et sp. nov. (Sphenophyllales), from the upper Devonian of South Africa. Organisms Diversity & Evolution, 19(1), 1-11.