Christensenia (plant)
| Christensenia | |
|---|---|
| Scientific classification | |
| Kingdom: | Plantae |
| Clade: | Tracheophytes |
| Division: | Polypodiophyta |
| Class: | Polypodiopsida |
| Order: | Marattiales |
| Family: | Marattiaceae |
| Genus: | Christensenia Maxon |
| Type species | |
| Christensenia aesculifolia (Blume) Maxon
| |
| Synonyms | |
|
Kaulfussia C.Presl | |
Christensenia is a genus of ferns in the botanical family Marattiaceae. The genus is confined to the Indo-Malayan region. The basal chromosome number for this genus is 2n=80.
Christensenia is unique in the Marattiaceae, because of its reticulate venation, palmately arranged leaves and radial synangia. Christensenia produces enormous amounts of spores, up to 7,000 spores per sporangium. The presence of a radial synangium is an archaic character, very similar to some of the fossil Asterothecaceae/Psaroniaceae, such as Scolecopteris. Christensenia itself has no fossil record.
Taxonomy
The Smith et al. classification of 2006, based on molecular phylogeny, placed Christensenia in Marattiaceae.[1] Subsequent classifications have maintained this placement.[2][3][4]
Species
After the 1993 revision by Rolleri, only two species and one variety are recognized:
- Christensenia aesculifolia (Blume) Maxon (type species)
- Christensenia aesculifolia var. korthalsii
- Christensenia lobbiana (de Vriese) Rolleri
References
- ^ Smith, Alan R.; Pryer, Kathleen M.; Schuettpelz, Eric; Korall, Petra; Schneider, Harald; Wolf, Paul G. (2006). "A classification for extant ferns" (PDF). Taxon. 55 (3): 705–731. doi:10.2307/25065646. JSTOR 25065646.
- ^ Christenhusz, Maarten J. M.; Zhang, Xian-Chun; Schneider, Harald (2011). "A linear sequence of extant families and genera of lycophytes and ferns" (PDF). Phytotaxa. 19: 7–54. doi:10.11646/phytotaxa.19.1.2.
- ^ Christenhusz, Maarten J.M.; Chase, Mark W. (2014). "Trends and concepts in fern classification". Annals of Botany. 113 (9): 571–594. doi:10.1093/aob/mct299. PMC 3936591. PMID 24532607.
- ^ PPG I (2016). "A community-derived classification for extant lycophytes and ferns". Journal of Systematics and Evolution. 54 (6): 563–603. doi:10.1111/jse.12229. S2CID 39980610.
- BRUMMITT, R. K. (1992) Vascular plant families and genera. Royal Botanic Gardens
- Pink, A. (2004). Gardening for the Million. Project Gutenberg Literary Archive Foundation.
- Rolleri, C. H. 1993. Revision of the genus Christensenia. Amer. Fern J. 83(1): 3–19.