Petrosaviaceae is a family of flowering plants belonging to a monotypic order, Petrosaviales. Petrosaviales are monocots, and are grouped within the

lilioid monocots Lilioid monocots (lilioids, liliid monocots, petaloid monocots, petaloid lilioid monocots) is an informal name used for a grade (grouping of taxa with common characteristics) of five monocot orders (Petrosaviales, Dioscoreales, Pandanales, L ...

. Petrosaviales are a very small order (one family, two genera and four species were accepted in 2016) of photosynthetic (''

Japonolirion ''Japonolirion'' is a genus of plants in the family Petrosaviaceae. There is only one known species, ''Japonolirion osense'', endemic to Japan Japan ( ja, 日本, or , and formally , ''Nihonkoku'') is an island country in East Asia. It ...

'') and rare leafless achlorophyllous, mycoheterotrophic plants (''

Petrosavia ''Petrosavia'' is a genus in the family Petrosaviaceae. It includes three species from eastern and southeastern Asia. # ''Petrosavia sakuraii'' (Makino) J.J.Sm. ex Steenis (syn ''P. miyoshia-sakuraii'') - Japan (Mino Province), China (Guangxi, ...

'') found in dark montane rainforests in Japan, China, Southeast Asia and Borneo. They are characterised by having

bract In botany, a bract is a modified or specialized leaf, especially one associated with a reproductive structure such as a flower, inflorescence axis or cone scale. Bracts are usually different from foliage leaves. They may be smaller, larger, or of ...

eate racemes,

pedicellate In botany, a pedicel is a stem that attaches a single flower to the inflorescence. Such inflorescences are described as ''pedicellate''. Description Pedicel refers to a structure connecting a single flower to its inflorescence. In the absenc ...

flowers, six persistent tepals,

septal nectaries Nectar is a sugar-rich liquid produced by plants in glands called nectaries or nectarines, either within the flowers with which it attracts pollinating animals, or by extrafloral nectaries, which provide a nutrient source to animal mutualists ...

, three almost distinct

carpels Gynoecium (; ) 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) ''pistils'' ...

, simultaneous

microsporogenesis Pollen is a powdery substance produced by seed plants. It consists of pollen grains (highly reduced microgametophytes), which produce male gametes (sperm cells). Pollen grains have a hard coat made of sporopollenin that protects the gametophyt ...

, monosulcate pollen, and follicular fruit.

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 recognized the family and assigned it to the clade monocots, unplaced as to order. The

APG III system The APG III system of flowering plant classification is the third version of a modern, mostly molecular-based, system of plant taxonomy being developed by the Angiosperm Phylogeny Group (APG). Published in 2009, it was superseded in 2016 by a fur ...

of 2009 and the APG IV system of 2016 placed family Petrosaviaceae in order Petrosaviales.

Genera

, two genera are accepted by the World Checklist of Selected Plant Families: * ''

'' Nakai, with one species * ''

'' Becc, with three species

Distribution and habitat

The plants in both genera are found in high-elevation habitats.

References

Bibliography

External links

''Petrosavia'' in ''Flora of China''

links at CSDL, Texas

The Plant List
* * {{Taxonbar, from=Q131296 Monocot families Petrosaviales