The Strobiloideae are an obsolete

taxon In biology, a taxon (back-formation from ''taxonomy''; : taxa) is a group of one or more populations of an organism or organisms seen by taxonomists to form a unit. Although neither is required, a taxon is usually known by a particular name and ...

omic name, a subclass of both

Monocotyledons Monocotyledons (), commonly referred to as monocots, (Lilianae ''sensu'' Chase & Reveal) are flowering plants whose seeds contain only one embryonic leaf, or cotyledon. A monocot taxon has been in use for several decades, but with various ranks and ...

and

Dicotyledons The dicotyledons, also known as dicots (or, more rarely, dicotyls), are one of the two groups into which all the flowering plants (angiosperms) were formerly divided. The name refers to one of the typical characteristics of the group: namely, ...

proposed by

Charles Bessey Charles Edwin Bessey (21 May 1845 – 25 February 1915) was an American botanist. Biography He was born at Milton, Wayne County, Ohio. He graduated in 1869 at the Michigan State Agricultural College. Bessey also studied at Harvard Universi ...

in 1915 in his taxonomic classification of plants. In this sense by not being unique it breaks the rules of

botanical nomenclature Botanical nomenclature is the formal, scientific naming of plants. It is related to, but distinct from taxonomy (biology), taxonomy. Plant taxonomy is concerned with grouping and classifying plants; Botany, botanical nomenclature then provides na ...

as currently used, however Bessey actually used a qualifying hyphenation (Alternifoliae-Strobiloideae and Oppositifoliae-Strobiloideae), a distinction not always recognised in reference to this scheme. Bessey believed in the strobiloid theory of plant evolution that postulated that the

Angiospermae Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (). The term angiosperm is derived from the Greek words (; 'container, vessel') and (; 'seed'), meaning that the seeds are enclosed within a fruit. The ...

(flowering plants) originated from

Cycadophyta Cycads are seed plants that typically have a stout and woody (ligneous) trunk with a crown of large, hard, stiff, evergreen and (usually) pinnate leaves. The species are dioecious, that is, individual plants of a species are either male or ...

, and that flowers originated from a primitive vegetative shoot that developed into a structure with

perianth The perianth (perigonium, perigon or perigone in monocots) is the non-reproductive part of the flower. It is a structure that forms an envelope surrounding the sexual organs, consisting of the calyx (sepals) and the corolla (petals) or tepal ...

stamens The stamen (: stamina or stamens) is a part consisting of the male reproductive organs of a flower. Collectively, the stamens form the androecium., p. 10 Morphology and terminology A stamen typically consists of a stalk called the filamen ...

and

carpels Gynoecium (; ; : gynoecia) is most commonly used as a collective term for the parts of a flower that produce ovules and ultimately develop into the fruit and seeds. The gynoecium is the innermost whorl of a flower; it consists of (one or more) ...

. From this arose two lines, the Strobiloideae (or Ranalian line) with

connation Connation in plants is the developmental fusion of organs of the same type, for example, petals to one another to form a tubular corolla. This is in contrast to adnation, the fusion of dissimilar organs. Such organs are described as connate or a ...

of like parts and the Cotyloideae (or Rosalian line) with connation of unlike parts, which he assigned as the two subclasses of monocots (called Alternifoliae by Bessey), but also of dicots (called Oppositifoliae by Bessey).

Subdivisions

The Alternifoliae Strobiloideae had five orders, arranged as follows: *:::1 subclassis ''Strobiloideae'' *:::::ordo

Alismatales The Alismatales (alismatids) are an order of flowering plants including about 4,500 species. Plants assigned to this order are mostly tropical or aquatic. Some grow in fresh water, some in marine habitats. Perhaps the most important food cro ...

*:::::ordo

Liliales Liliales is an order (biology), order of monocotyledonous flowering plants in the Angiosperm Phylogeny Group and Angiosperm Phylogeny Web List of systems of plant classification, system, within the lilioid monocots. This order of necessity includ ...

*:::::ordo Arales *:::::ordo Palmales *:::::ordo Graminales of these, the Alismatales were considered the most primitive. while the Oppositifoliae Strobiloideae had fourteen arranged in three superorders: *::2 classis ''Oppositifoliae'' *::::1 superordo ''Apopetalae-Polycarpellatae'' *::::2 superordo ''Sympetalae-Polycarpellatae'' *::::3 superordo ''Sympetalae-Dicarpellatae''

References

Sources

* {{cite book, last=Singh, first=Gurcharan, title=Plant Systematics: An Integrated Approach, year=2004, publisher=Science Publishers, isbn=1-57808-351-6, url=https://books.google.com/books?id=In_Lv8iMt24C&pg=10, pages=10–29, access-date=23 January 2014 Monocots Historically recognized angiosperm taxa