Petrosavia

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Petrosavia

Description

Erect, glabrous, saprophytic, pale yellow or cream coloured, herbs lacking chlorophyll. Leaves scale-like, spiral, sessile, entire; Ovary superior or semi-inferior; Fruit dry, dehiscing along the ventral suture; Seeds numerous, ovoid, with longitudinal ridges;

Distribution

Asia-Temperate:, Taiwan (Taiwanpresent) Asia-Tropical:, Borneopresent (Sabahpresent, Sarawakpresent); Malayapresent Central Celebes: present Japan: present Kwangsi: present N. half of Sumatra: present Prov. Mino: present S. China: present Tonkin: present
Japan (Prov. Mino), China (Kwangsi and Taiwan), Indo-China (Tonkin), in Malesia: Malaya, N. half of Sumatra, Borneo (Sabah, Sarawak), and Central Celebes.
In addition to the two species from Malesia and Japan, a third has been described from Tonkin and S. China (Kwangsi): Petrosavia sinii (Krause) Krause.

Notes

This genus has been placed in the Liliaceae (Liliales) by Krause (1930), the Petrosaviaceae (Alismatales) by Hutchinson (1959) and the Miyoshiaceae (Miyoshiales) by Nakai (1941). Both in being saprophytic and in having 2- or multi-seriate ovules it is anomalous in either the Liliales (sensu Hutchinson) or the Alismatales. Erdtman () described the pollen as 1-sulcoidate which is unknown in the Scheuchzeriaceae or Alismataceae (Alismatales) but present, although uncommon, in the Liliaceae. M. Y. Stant () investigated the anatomy of P. stellar is and found it to be indistinguishable from that in the (saprophytic) Triuridaceae (Triuridales). Although here retained in the Liliaceae it is admitted that further investigation may show it to be better placed elsewhere.
The roots lack root-hairs but contain an endotrophic mycorrhiza (Groom, 1895).

Citation

Groom - in Ann. Bot. 1895: 45
Steen. - in Trop. Natuur. 1934: 52
Krause - in E. & P., Nat. Pfl. Fam., ed. 2, 15a. 1930: f. 87
Hutch. - in Fam. Fl. Pl., ed. 2. 1959: 546
Nakai - in J. Jap. Bot. 1941: 191
Ridl. - in Fl. Mal. Pen. 1924: 322
Nakai - in J. Jap. Bot. 1941: 191
Nakai - in J. Jap. Bot. 1941: 191
Hutch., Kew Bull. 1933: 156
Krause - in E. & P., Nat. Pfl. Fam., ed. 2, 15a. 1930: 256
Ridl. - in J. Str. Br. R. As. Soc. 1891: 170