A Review of the Neotropical Genera Amalophyllon

A Review of the Neotropical Genera Amalophyllon

Selbyana 29(2): 157–176. 2008. AREVIEW OF THE NEOTROPICAL GENERA AMALOPHYLLON, NIPHAEA, AND PHINAEA (GESNERIACEAE-GLOXINIEAE) JOHN K. BOGGAN* National Museum of Natural History, Dept. of Botany, Smithsonian Institution, Washington, DC 20013-7012, USA. Email: [email protected] LAURENCE E. SKOG National Museum of Natural History, Dept. of Botany, Smithsonian Institution, Washington, DC 20013-7012, USA; Marie Selby Botanical Gardens, Sarasota, FL 34236-7726, USA. ERIC H. ROALSON School of Biological Sciences and Center for Integrated Biotechnology, Washington State University, Pullman, WA 99164-4236, USA. ABSTRACT. Previous molecular and morphological studies have revealed that the genus Phinaea (Gesne- riaceae-Gloxinieae) as circumscribed until now is polyphyletic. On the basis of these studies Phinaea s.s. is restricted to three species. Amalophyllon, originally described in Scrophulariaceae, is here recognized as a member of Gesneriaceae and as the first available generic name for the majority of the species previously included in Phinaea. An emended description of Amalophyllon is provided and the frequently confused genera Amalophyllon, Phinaea, and Niphaea are contrasted and the differences between them clarified. Eight species are transferred to Amalophyllon: A. albiflorum, A. caripense, A. divaricatum, A. laceratum, A. macrophyllum, A. repens, A. roezlii, and A. rubidum. Lectotypes are designated for two names, Niphaea parviflora and Napeanthus repens. Three new species, Amalophyllon clarkii, A. macrophylloides, and Ni- phaea pumila, are described. A key to the genera and species and lists of the currently known taxa for all three genera are provided. Key words: Gesneriaceae, Gesnerioideae, Gloxinieae, Scrophulariaceae, Amalophyllon, Niphaea, Phinaea INTRODUCTION and the taxonomic affinity of several taxa has remained uncertain. Morton (1937) observed, The neotropical genera Niphaea Lindl. and ‘‘Phinaea is one of the least known genera of Phinaea Benth. comprise species of small herbs Gesneriaceae. Seven species have been de- with subrotate white corollas and have been con- scribed, but most of these are known from single fused through much of their taxonomic history. specimens only.’’ More recent estimates of the Lindley (1841, 1842) described Niphaea with a number of species of Phinaea have ranged from single species, N. oblonga Lindl., and several ca. six (Skog 1979) to 16ϩ (Burtt & Wiehler additional species were subsequently described 1995, Wiehler 2002c). by other authors. Bentham (1876) segregated in Fritsch (1893–1894) classified Niphaea and the new genus Phinaea several of these species Phinaea with the Caribbean genus Bellonia L. that differed from N. oblonga in having stamen in tribe Bellonieae. Species of all three genera filaments longer (rather than shorter) than the have rotate to subrotate white corollas that are anthers and anther cells with distinct (as op- thought to have converged on a vibrational or posed to confluent) locules. On the basis of these ‘‘buzz’’ pollination syndrome (Wiehler 2002b). characters, most Niphaea species were subse- The genera of Bellonieae were included in an quently transferred to Phinaea (Hemsley 1882, expanded tribe Gloxinieae by Wiehler (1983), Fritsch 1893–1894, Solereder 1909, Morton although not necessarily as close relatives 1957). Other species transferred to Phinaea (Wiehler omitted any descriptions or discussions were originally described in the genera Trevi- of these genera). This position, however, was not rana Willd. (Poeppig 1840) and Napeanthus supported by Xu and Skog (1990), who contin- Gardner (Donnell Smith 1901, Brandegee 1914). ued to consider these three genera in the Bello- Although the distinction between Niphaea and nieae. Recent molecular analyses (Smith et al. Phinaea was discussed at length by Solereder 2004, Roalson et al. 2005a, Roalson et al. 2008) (1909), the two genera have remained confused suggest that Bellonia is better placed in tribe Gesnerieae, but Niphaea and Phinaea are best * Corresponding author. placed in tribe Gloxinieae. Further, the segre- 157 158SELBYANA Volume 29(2) 2008 TABLE 1. Characters distinguishing the three genera, Niphaea, Phinaea, and Amalophyllon. Character Niphaea Phinaea Amalophyllon Number of species 4 3-4 13ϩ Distribution Central America Central America, South Central America, South America, West Indies America Chromosome no. N ϭ 11 N ϭ 13 N ϭ 13, 26 Petiolation distinctly petiolate distinctly petiolate to subses- distinctly petiolate to subses- sile sile Leaf pairs (sub)equal (sub)equal subequal to unequal Leaf shape ovate to elliptic ovate to elliptic elliptic to lanceolate Leaf veins (color) never silvery sometimes silvery never silvery Leaf veins (number) (2–)5–7 pairs 4–6 pairs (4–)6–10ϩ pairs Corolla symmetry rotate to subrotate subrotate to slightly zygo- rotate to subrotate morphic Corolla color white white white or (rarely) pink Nectary absent annular absent Stamen filament length shorter than anthers longer than anthers longer than anthers Stamen filament curva- not curved curved curved ture Anther (thecae) shape oblong subglobose subglobose Anther thecae diver- parallel divergent divergent gence Ovary position half inferior half inferior half inferior to almost supe- rior Pedicel posture erect in fruit erect in fruit usually curved in fruit Capsule apex rostrate not rostrate not rostrate Capsule texture (at de- dry, lignified fleshy, poorly lignified dry, membranous hiscence) Valve dehiscence opening slightly spreading broadly opening slightly Valve trichomes present absent absent Seeds falling freely sticky, adhering to valves falling freely gation of Niphaea and Phinaea has been sup- 2008). However, further molecular and morpho- ported by molecular and morphological analyses logical analyses (see below) have shown Amalo- (Zimmer et al. 2002, Smith et al. 2004, Roalson phyllon rupestre Brandegee, the type species of the et al. 2005a), and these analyses do not support monotypic genus Amalophyllon Brandegee and a close relationship between the two genera as originally described in Scrophulariaceae (Brande- suggested by some authors (Fritsch 1893–1894, gee 1914), to belong to this group of Phinaea spe- Skog 1979). cies. We have therefore applied that generic name One unexpected result of these analyses (partic- to this group. Niphaea is closely related to neither ularly Roalson et al. 2005a, Roalson et al. 2008) Phinaea nor Amalophyllon; it is one of several is that two phylogenetically and morphologically Central American lineages in a polytomy at the distinct groups of species have been included in a base of the tribe with the Central American genera polyphyletic Phinaea. Although both groups nest Moussonia Regel, Achimenes Pers., Solenophora within Gloxinieae, these two groups are not close- Benth., Eucodonia Hanst., and Smithiantha Kuntze ly related to each other, and neither group is close- (Roalson et al. 2005a), or placed in a clade with ly related to Niphaea. The type species of Phinaea, the genera Eucodonia, Moussonia, and Smithian- P. albolineata (Hook.) Benth. ex Hemsl., belongs tha sister to the South American Gloxinieae clade to a clade containing Diastema Benth., Monopyle (Zimmer et al. 2002, Roalson et al. 2008). Moritz ex Benth., and several species previously Species of Niphaea, Phinaea, and Amalo- included in Gloxinia L’He´r. s.l. and later trans- phyllon are all small weak-stemmed herbs bear- ferred to the genera Gloxiniopsis Roalson & Bog- ing scaly rhizomes and small white flowers with gan, Nomopyle Roalson & Boggan, and Gloxinella rotate to subrotate corollas. Bellonia, while sim- (H.E.Moore) Roalson & Boggan (Roalson et al. ilar in floral morphology, is a woody shrub and 2005b). The other sampled species of Phinaea do lacks scaly rhizomes. Although superficially not appear to have any close relatives within the similar, closer examination of Niphaea, Phinaea, tribe, at least as it has been sampled so far (Smith and Amalophyllon has shown them to be distinct et al. 2004, Roalson et al. 2005a, Roalson et al. in several characters (TABLE 1). Species of all BOGGAN ET AL.: AMALOPHYLLON REVIEW 159 three genera tend to be geographically restricted, Phinaea, and Amalophyllon. Intergeneric hy- widely separated from each other, and poorly brids have been documented between Niphaea collected. Phinaea has an especially interesting and Achimenes (Worley 1979, 1997, 2002; distribution: the three known species are widely Wiehler 1983; Dates 1986) and between Phi- disjunct (Mexico, Colombia/northern Brazil, W. naea and Diastema (Martens 1996). Purported Indies) although any mechanisms for long-dis- hybrids between Niphaea and Amalophyllon (as tance dispersal are unknown; the fruits are sim- Phinaea), Niphaea and Eucodonia, Niphaea and ilar to the ‘‘splash cup’’ fruits described for Gloxinella (as Gloxinia), and Niphaea and Smi- some Gesneria species (Skog 1976). In contrast, thiantha (Worley 1997, 2002) are not well doc- the genus Niphaea is restricted to Mexico and umented. The nomenclature of nothogeneric Guatemala. Species of Amalophyllon cover a taxa involving these genera has been discussed wide geographic range in Central and South by Roalson and Boggan (2006). America and are discussed in more detail below. The purposes of this paper are to (1) recog- Following Bentham (1876), Phinaea has tradi- nize Amalophyllon as a member of Gesneri- tionally been separated from Niphaea on the ba- aceae; (2) provide a complete generic descrip- sis of floral characters: Niphaea with anther cells tion of Amalophyllon,

View Full Text

Details

  • File Type
    pdf
  • Upload Time
    -
  • Content Languages
    English
  • Upload User
    Anonymous/Not logged-in
  • File Pages
    20 Page
  • File Size
    -

Download

Channel Download Status
Express Download Enable

Copyright

We respect the copyrights and intellectual property rights of all users. All uploaded documents are either original works of the uploader or authorized works of the rightful owners.

  • Not to be reproduced or distributed without explicit permission.
  • Not used for commercial purposes outside of approved use cases.
  • Not used to infringe on the rights of the original creators.
  • If you believe any content infringes your copyright, please contact us immediately.

Support

For help with questions, suggestions, or problems, please contact us