Drepanophycaceae Explained

Drepanophycaceae is a family of extinct lycophytes[1] of Late Silurian to Late Devonian age, found in North America, China, Russia, Europe, and Australia.

Description

The stems are several mm to several cm in diameter and several cm to several metres long, erect or arched, dichotomizing occasionally, furnished with true roots at the base.[2] Vascular bundle an exarch actinostele, tracheids of primitive annular or helical type (so-called G-type). Leaves are unbranched microphylls several mm to 2 cm or more long with a single prominent vascular thread, arranged spirally to randomly on the stem. Homosporous sporangia borne singly on the upper leaf surface or in an axillary position.[3]

Drepanophycaceae differs from a related family of the same period, Asteroxylaceae, in having vascularized microphylls;[3] see Drepanophycales for more details.

Genera

The genera in the family are:[2]

Notes and References

  1. Web site: Drepanophycaceae. www.scientific-web.com . https://web.archive.org/web/20120301123850/http://www.scientific-web.com/en/Biology/Plants/Lycopodiophyta/Drepanophycaceae.html . March 1, 2012.
  2. Hueber 1992, p. 491 (Baragwanathia) and 492 (Drepanophycus)
  3. See tables 2 & 3 in Gensel (1992) for list of these anatomical details.