Fosterella gracilis (Rusby) L.B. Smith in Die Brom 2 40-45.2006 by
Pierre L. Ibisch, Jule Peters, Martina Rex, Katharina Schulte, Arturo Osinaga & Roberto Vásquez
Prelude
In the framework of our long-time and interdisciplinary studies of the Genus (Refer among others Ibisch et al. 2002, Rex et al. submitted manuscript) Fosterella gracilis earns a special mention.
It is about an interesting species which ‘was classified ' as an unwarranted synonym. It is a good example of how important it is to always consult Type material and original descriptions, because it can be lost in the framework of the taxonomic treatment through different researchers in the course of the time and valuable information lost.
As in other similar cases, the taxonomic treatment of the partially characteristic deficient Fosterella genus is difficult, if only looked at on the basis of herbarium material. There is practically no flower formation or colour and also the delicate scales on the leaf sheaths to refer to when judging only from Herbarium specimens. In the case of the genus Fosterella, the description of the species known first, was based mostly exclusively on dried Fosterella vouchers. Not all described taxa are today cultivated and thus observable. Robert Read and also our own investigations into the treatment of the genus could be only be achieved by the study of living plants. It presents a special challenge, of course, to assign new findings to old Type vouchers, that are only partial fragments.
The tumultuous taxonomic move of Catopsis gracilis to Fosterella penduliflora
Fosterella gracilis is returned after absolutely tumultuous taxonomic changes:
Rusby first described it in 1910 as Catopsis gracilis (Rusby 1910). Lyman B. Smith transferred it in 1934 to the genus Lindmania ( Smith 1934) until he established the genus Fosterella in 1960 (Smith 1960). Admittedly, Fosterella gracilis (Rusby) L.B. Smith first appeared in the first monograph of the genus ( Smith & Downs 1974), but it finally became classified as a synonym of Fosterella penduliflora by Smith & Read (1992) without reason – not even a forced taxonomic change. However, Robert Read did write later, in correspondence with Elvira Gross, criticising that at the time Smith forced a somewhat rash revue of the genus, that led to the Bradea publication. If Smith and Read had consulted the original description again, they would have become surely aware of the characteristics, that do not fit F. penduliflora.
Description by Rusby (1910):
« Catopsis gracilis sp. nov.
Basal sheaths white-tomentose, decreasingly pilose above; leaves densely rosulate at the base, 4-8 cm. long, 8 mm. broad a little above the middle, narrowed downward, above gradually attenuate, finely many nerved; bracts of the stem linear-attenuate; stem about 3 dm. high, erect or ascending, slender, paniculate above, the branches very slender, ascending, rather densely flowered; floral bracts about two-thirds the length of the strongly recurved pedicel, ovate, acute; sepals 2 mm. long, ovate, acuminate, rigid; petals (yellow?) 5-6 mm. long, lanceolate, nerved; longest filament 3 mm. long, its strongly curved anther half its length; pistil equaling the filaments, the style half as long as the ovoid, winged ovary, stout, linear, entire; capsule 3 mm. long. “Guanai, 1500 ft., Sept. 27, 1901” (No. 738).”
The yellow colour of the petals – noted by the collector on the label and actually the showiest characteristic was described by the author only under reservation (in brackets and with question marks). Furthermore, it could not be supported unequivocally from the dried Type voucher. This characteristic was lost in the taxonomic literature for the moment (shown below). Also, the scales on the leaves are clearly different from Fosterella penduliflora as well as the leaf base, never being white woolly or flaky shaggy (see. Fig. 3, 4, 5) but shield like scaled. The leaf base of F. gracilis is moreover hardly narrowed - even less than with F. penduliflora. The inflorescence of F. gracilis is distinctly dainty, the branches are very much slender curved and spreading wide ( fig. 6). Other differences - like the wider, less succulent and stiff leaves as well as the waxy surface of the entire inflorescence – does not come from the herbarium specimen or the original description. F. gracilis grows in contrast to F. penduliflora in larger groups as well as in clumps (Fig. 7 and 8.)
The resurrection of the species Fosterella gracilis from synonymity has since not been justified formally; even though in different earlier publications it has appeared without thorough examination ( for example Krömer et al. 1999).
Resurrection: the only yellow flowered Fosterella
As already mentioned by Schulte (2003), the yellow flowers got temporarily lost. Smith & Downs (1974) had no reference to „(yellow?) “ , and Smith & Read (1992) do not refer to it either. It was Robert Read, that finally recognized and has documented in an unpublished key, that the yellow flowering species is different from F. penduliflora. The most recent collection of living material which flowered in the collection of the Fundación Amigos de de la Naturaleza finally answered all doubts ( BOLIVIA. Dpto. Beni: Prov. Ballivian, approximately 5 km downstream from Rurrenabaque, on a boulder on the banks of the Río Beni 14°33'34"S, 67°30'35"W, 200 m, 28.10.2002, R. Vasquez, A. Osinaga, K. Schulte & M. Rex 4702; LPB, FR) (fig. 6). It is about the only known Fosterella with yellow flowers! First, the collectors believed they had discovered a new species, but gradually it was realised that the small question mark in the original description had impeded the recognition of this species for a long time.
In the present article, the characteristics of the discovered plant are documented and for the first time we have a photograph of the species.
The systematic position of Fosterella gracilis within the genus
Our molecular examinations of the genus Fosterella allow interesting insights into the relational position of Fosterella gracilis within the genus. In a first analysis, genetic fingerprints were produced for 18 Fosterella species, and also M. Rex, R. Vasquez, A. Osinaga & K. Schulte 281002-3; (LPB, FR); location and morphology identical to the ones of the plant described above R. Vásquez et al. 4702, and on the basis of these characteristics a family tree for the genus Fosterella has been constructed( Rex et al., submitted manuscript). This molecular family tree shows an isolated position for Fosterella gracilis that suggests a certain systematic autonomy of the taxa. However the data base for this analysis is not yet sufficient in order to get information on the relationship of Fosterella gracilis to the other Fosterella apecies. Our latest molecular studies ( Rex et al. 2006) that is founded on the comparative sequence-analysis of the ancestry of different Chloroplast areas, more exact statements now allow us to view the relational position of Fosterella gracilis. The molecular family tree produced on this data base clearly shows that F. penduliflora, F. latifolia, F. chiquitana and F. gracilis form a natural complex and it is therefore possible to attribute to a common ancestor. Fosterella gracilis does not stand in this family tree within the group of the examined F. penduliflora test, which also goes against its synonymising with F. penduliflora. In stead it places Fosterella gracilis in an isolated position in this group which a clear hint as to its genetic autonomy. The results of the molecular examinations show the restoration of the taxon Fosterella gracilis is justified.
Peters et al in Selbyana 29(2): 182-194. 2008
We recently re-established this taxon (Ibisch et al. 2006), which had been synonymized by Smith & Downs (1992) under Fosterella pen¬duliflora. Originally described as Catopsis gracilis, and temporarily shifted to Lindmania, this species had an astonishing taxonomic his¬tory. The disregard of information provided by the collector and included in the original de¬scription by later authors led to taxonomic con¬fusion. Fosterella gracilis from the lower val¬leys and foothills of the North-Bolivian Andes is the only known yellow-flowering species in the genus. Not only the floral color, but also sev-eral other characters suggest that the species is distinct from F. penduliflora. These include the abaxially tomentose leaves, and the very slender and glaucous inflorescence. Evidence from mo¬lecular studies (Rex et al. 2007) also confirms the genetic distinctness of F. gracilis from F. penduliflora (compare FIGURE 3).
When Rusby (1910), based on the collection R.S. Williams 738, described Catopsis gracilis, he did not choose a holotype from among the three specimens. Therefore, in accordance with the ICBN (2005), the designation of the speci¬men preserved in NY by Smith & Downs (1974) as holotype should be changed to lectotype.
Habitat & Ecology
Fosterella gracilis seems to be limited geographically to the base of the Andes as well as in sub Andean areas in North Bolivian valleys from ca. 200 to over 1000 m.above sea level. There it comes from naturally occurring forest-free slopes as well as on rocks (Fig 8, 9). Meanwhile, further collections have occurred in the Madidi National Park: Bolivia. Dpto. La Paz: Prov. Franz Tamayo, Madidi, Virgen Del Rosario-Pata, 1000-1300 m, 14°36’48“S, 68°40’59“ W, 10. Nov 2003, A. Fuentes & R. Cuevas 5887,( LPB, NY) as wellas Bolivia. Depto. La Paz: Prov. Franz Tamayo, Madidi, Apolo, Unapa, 1022 m, 14°32’26“S, 68°29’46“ W, 1. Sept 2004, A. Fuentes & C. Aldana 6371,( LPB, MO). The collectors documented the yellow colour of the flowers in each case. —SeeDie Bromelie
We recently re-established this taxon (Ibisch et al. 2006), which had been synonymized by Smith & Downs (1992) under Fosterella penduliflora. Originally described as Catopsis gracilis, and temporarily shifted to Lindmania, this species had an astonishing taxonomic history. The disregard of information provided by the collector and included in the original description by later authors led to taxonomic confusion. Fosterella gracilis from the lower valleys and foothills of the North-Bolivian Andes is the only known yellow-flowering species in the genus. Not only the floral color, but also several other characters suggest that the species is distinct from F. penduliflora. These include the abaxially tomentose leaves, and the very slender and glaucous inflorescence. Evidence from molecular studies (Rex et al. 2007) also confirms the genetic distinctness of F. gracilis from F. penduliflora (compare FIGURE 3). When Rusby (1910), based on the collection R.S. Williams 738, described Catopsis gracilis, he did not choose a holotype from among the three specimens. Therefore, in accordance with the ICBN (2005), the designation of the specimen preserved in NY by Smith & Downs (1974) as holotype should be changed to lectotype. —SeePeters 2009p. 29(2): 189
