family
Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...
of
flowering plant
Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (), commonly called angiosperms. They include all forbs (flowering plants without a woody stem), grasses and grass-like plants, a vast majority of ...
s in the
order
Order, ORDER or Orders may refer to:
* Categorization, the process in which ideas and objects are recognized, differentiated, and understood
* Heterarchy, a system of organization wherein the elements have the potential to be ranked a number of d ...
APG IV system
The APG IV system of flowering plant classification is the fourth version of a modern, mostly molecular-based, system of plant taxonomy for flowering plants (angiosperms) being developed by the Angiosperm Phylogeny Group (APG). It was publish ...
, it includes about 40 genera and 900 known species. The type genus is ''
Asphodelus
''Asphodelus'' is a genus of mainly perennial flowering plants in the asphodel family Asphodelaceae that was first described by Carl Linnaeus in 1753. The genus was formerly included in the lily family (Liliaceae). The genus is native to temper ...
''.
The family has a wide but scattered
distribution Distribution may refer to:
Mathematics
*Distribution (mathematics), generalized functions used to formulate solutions of partial differential equations
*Probability distribution, the probability of a particular value or value range of a varia ...
throughout the
tropics
The tropics are the regions of Earth surrounding the Equator. They are defined in latitude by the Tropic of Cancer in the Northern Hemisphere at N and the Tropic of Capricorn in
the Southern Hemisphere at S. The tropics are also referred ...
cosmetic
Cosmetic may refer to:
* Cosmetics, or make-up, substances to enhance the beauty of the human body, apart from simple cleaning
*Cosmetic, an adjective describing beauty, aesthetics, or appearance, especially concerning the human body
*Cosmetic, ...
uses. ''Xanthorrhoea'' is
endemic
Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found els ...
Members of the Asphodelaceae are diverse, with few characters uniting the three subfamilies currently recognized. The presence of anthraquinones is one common character. The flowers (the
inflorescence
An inflorescence is a group or cluster of flowers arranged on a stem that is composed of a main branch or a complicated arrangement of branches. Morphologically, it is the modified part of the shoot of seed plants where flowers are formed ...
) are typically borne on a leafless stalk ( scape) which arises from a basal rosette of leaves. The individual flowers have jointed stalks ( pedicels). A disk of woody tissue (a hypostase) is present at the base of the
ovule
In seed plants, the ovule is the structure that gives rise to and contains the female reproductive cells. It consists of three parts: the '' integument'', forming its outer layer, the ''nucellus'' (or remnant of the megasporangium), and the f ...
.
The subfamily Xanthorrhoeoideae contains only the genus '' Xanthorrhoea'', native to Australia. Plants typically develop thick woody stems; the flowers are arranged in a dense spike. Members of the subfamily
Asphodeloideae
Asphodeloideae is a subfamily of the monocot family Asphodelaceae in the order Asparagales. It has previously been treated as a separate family, Asphodelaceae ''sensu stricto''. The family Asphodelaceae has now been proposed to be a nomen cons ...
are often leaf succulents, such as aloes and haworthias, although the subfamily also includes ornamental perennials such as red hot pokers ('' Kniphofia''). Members of the subfamily Hemerocallidoideae are varied in habit. Daylilies (''
Hemerocallis
A daylily or day lily is a flowering plant in the genus ''Hemerocallis'' , a member of the family Asphodelaceae, subfamily Hemerocallidoideae. Despite the common name, it is not in fact a lily. Gardening enthusiasts and horticulturists hav ...
'') are one of the widely grown members of this subfamily.
paraphyletic
In taxonomy (general), taxonomy, a group is paraphyletic if it consists of the group's most recent common ancestor, last common ancestor and most of its descendants, excluding a few Monophyly, monophyletic subgroups. The group is said to be pa ...
group, the "lower Asparagales", which includes the Asphodelaceae as defined here, and a well-supported
monophyletic
In cladistics for a group of organisms, monophyly is the condition of being a clade—that is, a group of taxa composed only of a common ancestor (or more precisely an ancestral population) and all of its lineal descendants. Monophyletic ...
group of "core Asparagales", comprising Amaryllidaceae ''sensu lato'' and
Asparagaceae
Asparagaceae, known as the asparagus family, is a family of flowering plants, placed in the order Asparagales of the monocots. The family name is based on the edible garden asparagus, '' Asparagus officinalis''. Those who live in the temperate ...
''sensu lato''. Three separate families were at one time recognized (e.g. in the first
APG system
The APG system (Angiosperm Phylogeny Group system) of plant classification is the first version of a modern, mostly molecular-based, system of plant taxonomy. Published in 1998 by the Angiosperm Phylogeny Group, it was replaced by the improved ...
of 1998): Asphodelaceae, Hemerocallidaceae and Xanthorrhoeaceae. Molecular phylogenetic studies have shown that the three are closely related, although Rudall considered that the combination into a single clade was not supported by morphological analysis. The most recent APG classification, the
APG IV system
The APG IV system of flowering plant classification is the fourth version of a modern, mostly molecular-based, system of plant taxonomy for flowering plants (angiosperms) being developed by the Angiosperm Phylogeny Group (APG). It was publish ...
of 2016, places the three former families into a single family, the Asphodelaceae ''sensu lato''. The former families are treated as three subfamilies: Asphodeloideae, Hemerocallidoideae and Xanthorrhoeoideae.
The following phylogenetic tree for Asphodelaceae sensu lato is based on a
molecular phylogenetic
Molecular phylogenetics () is the branch of phylogeny that analyzes genetic, hereditary molecular differences, predominantly in DNA sequences, to gain information on an organism's evolutionary relationships. From these analyses, it is possible to ...
chloroplast
A chloroplast () is a type of membrane-bound organelle known as a plastid that conducts photosynthesis mostly in plant and algal cells. The photosynthetic pigment chlorophyll captures the energy from sunlight, converts it, and stores it ...
gene
In biology, the word gene (from , ; "... Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a b ...
s rbcL, matK, and ndhF. All branches have at least 70% bootstrap support. Of the 36 genera recognized by the authors, 29 were sampled. ''Eccremis'' was not sampled, but is added here because it is known to be closely related to ''Pasithea'' and is often combined with it. ''Hodgsoniola'' belongs somewhere in the grade from ''Tricoryne'' to ''Johnsonia''. The unsampled genera, ''Astroloba, Chortolirion'' and ''Gasteria'', belong to subfamily Asphodeloideae.
History
The family now called Asphodelaceae has had a complex history; its circumscription and placement in an order have varied widely.
In the
Cronquist system
The Cronquist system is a taxonomic classification system of flowering plants. It was developed by Arthur Cronquist in a series of monographs and texts, including ''The Evolution and Classification of Flowering Plants'' (1968; 2nd edition, 1988) ...
of 1981, members of the Asphodelaceae were placed in the order Liliales. Cronquist had difficulty classifying the less obviously delineated lilioid monocots; consequently, he placed taxa from both the modern orders Asparagales and Liliales into a single family
Liliaceae
The lily family, Liliaceae, consists of about 15 genera and 610 species of flowering plants within the order Liliales. They are monocotyledonous, perennial, herbaceous, often bulbous geophytes. Plants in this family have evolved with a f ...
.
In some of the older
systems of plant taxonomy
A system is a group of Interaction, interacting or interrelated elements that act according to a set of rules to form a unified whole. A system, surrounded and influenced by its environment (systems), environment, is described by its boundaries, ...
, such as the Cronquist system, the plants that now form the family Dasypogonaceae were also considered to belong to this family.
Molecular phylogenetic
Molecular phylogenetics () is the branch of phylogeny that analyzes genetic, hereditary molecular differences, predominantly in DNA sequences, to gain information on an organism's evolutionary relationships. From these analyses, it is possible to ...
studies have shown that Dasypogonaceae belongs to the commelinids and is therefore not even in the same order as Asphodelaceae.
The decision to group three formerly separate families, Asphodelaceae sensu stricto, Hemerocallidaceae and Xanthorrhoeaceae, into a single family first occurred as an option in the APG II system of 2003. The name used for the broader family was then Xanthorrhoeaceae; earlier references to the Xanthorrhoeaceae relate only to the subfamily Xanthorrhoeoideae. The changes were a consequence of improvement in molecular and morphological analysis and also a reflection of the increased emphasis on placing families within an appropriate order.
The APG III system of 2009 dropped the option of keeping the three families separate, using only the expanded family, still under the name Xanthorrhoeaceae. Anticipating a decision to conserve the name Asphodelaceae over Xanthorrhoeaceae (which came to pass in 2017), the
APG IV system
The APG IV system of flowering plant classification is the fourth version of a modern, mostly molecular-based, system of plant taxonomy for flowering plants (angiosperms) being developed by the Angiosperm Phylogeny Group (APG). It was publish ...
uses Asphodelaceae as the name for the expanded family.
The three previous families were then the subfamilies
Asphodeloideae
Asphodeloideae is a subfamily of the monocot family Asphodelaceae in the order Asparagales. It has previously been treated as a separate family, Asphodelaceae ''sensu stricto''. The family Asphodelaceae has now been proposed to be a nomen cons ...
, Hemerocallidoideae and Xanthorrhoeoideae. Earlier these three had been treated as separate families.
The family Asphodelaceae was made a nomen conservandum (conserved name) in 2017. Previously, the name Xanthorrhoeaceae had priority. This was anticipated in the APG IV family lists.
Genera
The genera listed below are from the
World Checklist of Selected Plant Families
The World Checklist of Selected Plant Families (usually abbreviated to WCSP) is an "international collaborative programme that provides the latest peer reviewed and published opinions on the accepted scientific names and synonyms of selected pl ...
, with the division into subfamilies based on APWeb .
The nothogenus ''Gasteraloe'' contains hybrids between ''Aloe'' and ''Gasteria''.
The genus '' Xeronema'' is now placed in a separate family, the Xeronemataceae.