ALBERT

Description: Typhonium trilobatum, T. flagelliforme, T. roxburghii, and T. blumei are taxonomically distinct, but their epithets (including that of T. divaricatum, nom. illegit.) frequently have been interchanged, primarily because of nomenclatural problems involving synonymy and (mis)typifications. It is concluded that the last monographer (Engler, 1920) used the correct names for the four species, except for what he called T. divaricatum, here called T. blumei.

Description: This genus, like Anadendrum and Heteropsis, is intermediate between the subfamilies Pothoideae and Monsteroideae as constituted by Engler (1920, p.63). When Schott originally described the genus he placed it next to Anadendrum (Pothoideae). Engler (1879, p. 100) left it in the Pothoideae next to Heteropsis which followed Anadendrum. Later, Engler (1908, p. 118) transferred Amydrium to the Monsteroideae as a monotypic genus. In the same publication (p. 1) Engler established a new genus, Epipremnopsis, which he placed next to Anadendrum in the Pothoideae. In this treatment I propose to unite Epipremnopsis and its three species with the hitherto monotypic genus Amydrium. The species concerned are rather different from each other. Study of them in the wild and the herbarium suggested that they were congeneric. In a recent survey of aroid floral anatomy (Eyde et al., p. 481, 486, fig. 9—15, 27) it was found that Amydrium humile and Epipremnopsis media have virtually identical unilocular ovaries with a single, deeply intrusive placenta (since found in E. magnifica and zippeliana). This striking condition has arisen from a bilocular ovary by abortion of the opposing placenta. Among the other aroids this character in known only in the genus Epipremnum and is the fundamental difference separating it from its near relatives, Rhaphidophora and Scindapsus Amydrium is distinguished from Epipremnum by its lack of needlelike trichosclereids which are abundant in the flowers and fruits of Epipremnum.

Description: Up to the present time Xenophya has been a monotypic genus known only from its type collection. It is closely related to the genus Alocasia from which it may be distinguished by its entirely persistent spathe and anatropous ovules. In Alocasia the upper part of the spathe quickly withers and is lost and the ovules are suborthotropous. Schott (Bonplandia 10, 1862, 148) described a Philippine plant as ‘Alocasia? (Schizocasta) portei’. Schizocasia cannot be considered as validly published here because the author did not accept the name (Art. 34, ICBN). Xenophya Schott (1863) was published by Schott and placed in the tribe Zomicarpeae of the subfamily Aroideae. Engler (in DC., Monogr. Phan. 2, 1879, 495) included Schizocasia portei as representing a monotypic genus but changed his mind in the Additamenta on page 645 and transterred the species back to Alocasia. Again, ‘Schizocasia’ was not validly published because the author did not accept the name. In the same publication Engler (p. 526—7) accepted Xenophya in the Zomicarpeae but expressed his great uncertainty about the placement of the genus. The genus Schizocasia was finally established by Engler (Bot. Jahrb. I, 1880, 185—6) based on a Papuan species, S. acuta. In this publication Engler comments how similar his plant is to Xenophya but it differs by the micropyles of the ovules of Schizocasia facing out and facing in in Xenophya. Finally, Engler (Pflanzenr. Heft 73 1920, 60) continued the placement of Xenophya in the Zomicarpeae but said in a note that it would be better placed in the Colocasioideae (where Schizocasia is placed). In the same publication Engler (Pflanzenr. Heft 71, 1920, 115) in his discussion of Schizocasia said that Schizocasia appears to be very similar to Xenophya but differs in the facing of its ovules and above all in its staminate flowers.

Description: The genus Spathiphyllum was recently revised by G. S. Bunting (Mem. New York Bot. Gard. 10, 3, 1960, p. 1\xe2\x80\x9454). Engler (Pflanzenr. IV.23B Heft 37, 1908, p. 118) concluded that the closest relative of Spathiphyllum was the small Papuan genus Holochlamys Engl. and placed it in the Spathiphylleae, the second of two tribes of the subfamily Monsteroideae. The discovery of large numbers of distinctive trichosclereids (Nicolson, Amer. Journ. Bot. 47, 1960, p. 601) only in the species of these two genera supports Engler\xe2\x80\x99s uniting of the genera as a tribe.\nThe two genera can be distinguished by the following key: I. Peduncle as long as or longer than the petioles. Spathe persistent ........ Spathiphyllum I. Peduncle much shorter than petioles. Spathe marcescent ............. Holochlamys

Description: Up to the present time Xenophya has been a monotypic genus known only from its type collection. It is closely related to the genus Alocasia from which it may be distinguished by its entirely persistent spathe and anatropous ovules. In Alocasia the upper part of the spathe quickly withers and is lost and the ovules are suborthotropous.\nSchott (Bonplandia 10, 1862, 148) described a Philippine plant as \xe2\x80\x98Alocasia? (Schizocasta) portei\xe2\x80\x99. Schizocasia cannot be considered as validly published here because the author did not accept the name (Art. 34, ICBN). Xenophya Schott (1863) was published by Schott and placed in the tribe Zomicarpeae of the subfamily Aroideae. Engler (in DC., Monogr. Phan. 2, 1879, 495) included Schizocasia portei as representing a monotypic genus but changed his mind in the Additamenta on page 645 and transterred the species back to Alocasia. Again, \xe2\x80\x98Schizocasia\xe2\x80\x99 was not validly published because the author did not accept the name. In the same publication Engler (p. 526\xe2\x80\x947) accepted Xenophya in the Zomicarpeae but expressed his great uncertainty about the placement of the genus. The genus Schizocasia was finally established by Engler (Bot. Jahrb. I, 1880, 185\xe2\x80\x946) based on a Papuan species, S. acuta. In this publication Engler comments how similar his plant is to Xenophya but it differs by the micropyles of the ovules of Schizocasia facing out and facing in in Xenophya. Finally, Engler (Pflanzenr. Heft 73 1920, 60) continued the placement of Xenophya in the Zomicarpeae but said in a note that it would be better placed in the Colocasioideae (where Schizocasia is placed). In the same publication Engler (Pflanzenr. Heft 71, 1920, 115) in his discussion of Schizocasia said that Schizocasia appears to be very similar to Xenophya but differs in the facing of its ovules and above all in its staminate flowers.

Description: Typhonium trilobatum, T. flagelliforme, T. roxburghii, and T. blumei are taxonomically distinct, but their epithets (including that of T. divaricatum, nom. illegit.) frequently have been interchanged, primarily because of nomenclatural problems involving synonymy and (mis)typifications. It is concluded that the last monographer (Engler, 1920) used the correct names for the four species, except for what he called T. divaricatum, here called T. blumei.

Description: This genus, like Anadendrum and Heteropsis, is intermediate between the subfamilies Pothoideae and Monsteroideae as constituted by Engler (1920, p.63). When Schott originally described the genus he placed it next to Anadendrum (Pothoideae). Engler (1879, p. 100) left it in the Pothoideae next to Heteropsis which followed Anadendrum. Later, Engler (1908, p. 118) transferred Amydrium to the Monsteroideae as a monotypic genus. In the same publication (p. 1) Engler established a new genus, Epipremnopsis, which he placed next to Anadendrum in the Pothoideae. In this treatment I propose to unite Epipremnopsis and its three species with the hitherto monotypic genus Amydrium.\nThe species concerned are rather different from each other. Study of them in the wild and the herbarium suggested that they were congeneric. In a recent survey of aroid floral anatomy (Eyde et al., p. 481, 486, fig. 9\xe2\x80\x9415, 27) it was found that Amydrium humile and Epipremnopsis media have virtually identical unilocular ovaries with a single, deeply intrusive placenta (since found in E. magnifica and zippeliana). This striking condition has arisen from a bilocular ovary by abortion of the opposing placenta. Among the other aroids this character in known only in the genus Epipremnum and is the fundamental difference separating it from its near relatives, Rhaphidophora and Scindapsus Amydrium is distinguished from Epipremnum by its lack of needlelike trichosclereids which are abundant in the flowers and fruits of Epipremnum.