Petrosaviaceae

Petrosaviaceae
Petrosavia sakuraii
Scientific classification
Kingdom:	Plantae
(unranked):	Angiosperms
(unranked):	Monocots
Order:	Petrosaviales Takht.
Family:	Petrosaviaceae Hutch.[1]
Type species
Petrosavia stellaris Becc.
Genera
Japonolirion Petrosavia

Petrosaviaceae is a family of flowering plants belonging to a monotypic order, Petrosaviales. Petrosaviales are monocots, and are grouped within the lilioid monocots. Petrosaviales are a very small order (1 family, 2 genera, about 5 species) of rare leafless achlorophyllous, mycoheterotrophic plants found in dark montane rainforests in Japan, China, Southeast Asia and Borneo. They are characterised by having bracteate racemes, pedicellate flowers, six persistent tepals, septal nectaries, three almost distinct carpels, simultaneous microsporogenesis, monosulcate pollen, and follicular fruit.^[2]

Taxonomy

The family has only been recognized in modern classifications, previously the plants involved were usually treated as belonging to the family Liliaceae.

The APG II system, of 2003, does recognize this family and assigns it to the clade monocots, unplaced as to order. This family then consists of two genera Japonolirion and Petrosavia. In circumscribing the family in this way, APG II departs from the APG system, of 1998, which treated each of these genera as constituting its own family. The APG III system, of 2009, place family Petrosaviaceae in order Petrosaviales.^[1]

Japonolirion is taken to consist of one species and Petrosavia of three species.

Distribution and habitat

The plants in both genera are found in high-elevation habitats and have bracteate racemes, pedicellate flowers, six persistent tepals, septal nectaries, three nearly distinct carpels, simultaneous microsporogenesis, monosulcate pollen, and follicular fruits.

References

1. Angiosperm Phylogeny Group (2009). "An update of the Angiosperm Phylogeny Group classification for the orders and families of flowering plants: APG III" (PDF). Botanical Journal of the Linnean Society 161 (2): 105–121. doi:10.1111/j.1095-8339.2009.00996.x. Retrieved 2013-06-26.
2. Cameron, Chase & Rudall 2003

External links

• Petrosavia in Flora of China
• NCBI Taxonomy Browser
• links at CSDL, Texas
• The Plant List
• Cameron, Kenneth M.; Chase, Mark W.; Rudall, Paula J. (July 2003), "Recircumscription of the monocotyledonous family Petrosaviaceae to include Japonolirion", Brittonia 55 (3): 214–225, doi:10.1663/0007-196X(2003)055[0214:ROTMFP]2.0.CO;2, JSTOR 3218442