Asphodelaceae: A Distinct Family from Other liliod Monocot Groups
Asphodelaceae
(Aloe Family)
CLASSIFICATION
Dahlgren et al. (1985) divided the Monocotyledons into several superorders of which the Liliiflorae is the largest. The order Asparagales is the largest of the five orders within Liliiflorea. One of the families within Asparagales recognized by Dahlgren and his co-workers was Asphodelaceae (Chase et al. (2000). Asphodelaceae consists of the sub-families, the Asphodeloideae and the Alooideae. The Alooideae consists of six genera of which Aloe is the largest. The sub-family Alooideae are noted for their spectacular secondary growth, a characteristic used to define the Alooideae as monophyletic. On the other hand, some workers within the taxa have considered the above two subfamilies were for sometime, considered to be separate families, the Asphodelaceae and Alooideae (Dagne and Yenesaw 1994). Determining the proper phylogeny was difficult because some authors have argued that Aspodeloideae is not a monophyletic group. Also, the Aspodeloideae are more varied and share a great deal of morphological similarities between other groups (Chase et al. 2000). The latest generation of chemical information on species belonging to these two groups is believed to reveal the relationships among the various taxa and to assist in establishing taxonomic classifications at various levels (Dagne and Yenesaw 1994). However, there is still not strong enough evidence suggesting both sub-families should not be included in a single family, the Asphodelaceae (Bisrata 2000).
MORPHOLOGY
Asphodelaceae is a distinct family from other liliod monocot groups by a combination of several morphological and reproductive features: simultaneous microsporogensis, atypical ovular structure, lacking steroidal saponins, producing seeds with arils, and the general presence of anthraquinones. Basic morphological features of genera within the Asphodelaceae consist of mostly herbs, shrubs, and sometimes arborescent, which grows into woody forms with
(Aloe Family)
CLASSIFICATION
Dahlgren et al. (1985) divided the Monocotyledons into several superorders of which the Liliiflorae is the largest. The order Asparagales is the largest of the five orders within Liliiflorea. One of the families within Asparagales recognized by Dahlgren and his co-workers was Asphodelaceae (Chase et al. (2000). Asphodelaceae consists of the sub-families, the Asphodeloideae and the Alooideae. The Alooideae consists of six genera of which Aloe is the largest. The sub-family Alooideae are noted for their spectacular secondary growth, a characteristic used to define the Alooideae as monophyletic. On the other hand, some workers within the taxa have considered the above two subfamilies were for sometime, considered to be separate families, the Asphodelaceae and Alooideae (Dagne and Yenesaw 1994). Determining the proper phylogeny was difficult because some authors have argued that Aspodeloideae is not a monophyletic group. Also, the Aspodeloideae are more varied and share a great deal of morphological similarities between other groups (Chase et al. 2000). The latest generation of chemical information on species belonging to these two groups is believed to reveal the relationships among the various taxa and to assist in establishing taxonomic classifications at various levels (Dagne and Yenesaw 1994). However, there is still not strong enough evidence suggesting both sub-families should not be included in a single family, the Asphodelaceae (Bisrata 2000).
MORPHOLOGY
Asphodelaceae is a distinct family from other liliod monocot groups by a combination of several morphological and reproductive features: simultaneous microsporogensis, atypical ovular structure, lacking steroidal saponins, producing seeds with arils, and the general presence of anthraquinones. Basic morphological features of genera within the Asphodelaceae consist of mostly herbs, shrubs, and sometimes arborescent, which grows into woody forms with
Cited: Adams S.P., I.J. Leitch, M.D. Bennett, M.W. Chase, and A.R. Leitch. 2000. Ribosomal DNA Evolution and Phylogeny in Aloe (Asphodelaceae) Eguiarte. 2000. Phylogenetics of Asphodelaceae (Asparagales): An Analysis of Plastid rbcL and trnL-F DNA Sequences Dagne E., and A. Yenesew. 1994. Anthraquinones and chemotaxonomy of the Asphodelaceae Glen, H.F. & Hardy.D.S. 2000. Aloe. Flora of Southern Africa . National Botanical Institute, Pretoria 5:1-1. Judd W.S., C.S. Cambell, E.A. Kellogg, P.F. Stevens, and M.J. Donoghue. 2002. Plant Systematics: A Phylogenetic Approach Van Wyk, B-E, van Oudtshoorn, B & Gericke, N. 1997. Medicinal Plants of South Africa Viljoen, A.M., B-E. van Wyk, and F.R. van Heerden. 1998. Distribution and Chemotaxonomic significance of flavonoids in Aloe Watson L., and M. J. Dallwitz (1992 onwards). The Families of Flowering Plants: Descriptions, Illustrations, Identification, and Information Retrieval