Materials to the revision of the genus Cranichis (Orchidaceae) in Bolivia

Abstract The diversity of Cranichis in Bolivia is evaluated. An updated key for identifying species is provided. Morphological characteristics of 15 species of Bolivian Cranichis are presented together with illustrations of their floral segments. The occurrence of C.diphylla, C.lehmannii, and C.muscosa in this country was not confirmed. In our opinion the previously published Bolivian record for C.polyantha is doubtful. For the first time, C.badia and C.longipetiolata are reported in this country. Two new species of Cranichis are described.

amined from outside Bolivia are listed in Szlachetko 2013, 2019;Szlachetko and Kolanowska 2013, and books of Szlachetko 2016Szlachetko and Kolanowska 2020. The list of species of Bolivian Cranichis examined in this study is provided in Supplementary Information (Annex 1). Information on the habitats of Bolivian Cranichis was gathered during field studies and from the data on herbarium labels. Characteristics of species that are reported from Bolivia, but not confirmed or examined in this study, were prepared based on specimens collected in other regions, as well as the literature.
All herbarium specimens were examined in the standard way. The size and shape of the leaves and length of the scape were studied first. Then the details of the inflorescence (e.g. form of the floral bracts and ovaries) were examined. Three flowers from the middle part of the inflorescence were studied. The floral segments were observed under a stereoscopic microscope, after softening the flowers in boiling water.
Only those localities that could be identified based on information on the labels of the herbarium specimens were included in the distribution maps compiled using ArcGis 10.6 (Esri, Redlands, CA, USA).

Nomenclature
The electronic version of this article in portable document format is a published work according to the International Code of Nomenclature for algae, fungi and plants (Turland et al. 2018) and hence the new names contained in the electronic version are effectively published under that Code. In addition, new names included in this work that were issued with identifiers by IPNI will eventually be made available to the Global Names Index. The IPNI Life Science Identifiers (LSIDs) can be obtained and the associated information viewed using any standard web browser by appending the LSID contained in this publication to the prefix http://ipni.org/. The online version of this paper is archived and available from the following digital repositories: PeerJ, PubMed Central, and CLOCKSS.

Results
Here the characteristics of 15 Bolivian Cranichis are presented. The occurrence of C. diphylla, C. lehmannii, and C. muscosa in this country was not confirmed as we were not able to find reference material in the collection of Vasquez deposited in LPB. Moreover, in our opinion the previously published Bolivian record for C. polyantha is doubtful and is discussed below. Two new species of Cranichis are described in this paper and for the first time we are reporting the occurrence of C. badia and C. longipetiolata in Bolivia. While both Schweinfurth (1958) and Vásquez et al. (2014) accepted the name Cranichis multiflora (Poepp. & Endl.) Cogn., in our opinion this taxon should be classified within Ponthieva R.Br.   Garay (1978: 191): AMES-drawing).
Etymology. Dedicated to Stephan G. Beck, who collected the type specimen and is a former director of Herbario Nacional de Bolivia.
Habitat and ecology. Terrestrial in Yungas humid, secondary montane forest at an altitude of ca. 1730 m. Flowers in February.

Notes.
This species resembles C. lehmannii in general flower morphology, but its petals are spathulate-obovate, widest apically and similar in shape to those of C. diphylla. Leaves of C. lehmannii are smaller (up to 11 cm long), its ovary is glabrous (microscopically ciliate in C. beckii), lateral sepals are 2-veined (vs 1-veined in C. beckii) Table 1. Comparative morphology of C. beckii and C. lehmannii.
Habitat and ecology. According to Vásquez et al. (2014) this species occurs in the Yungas ecoregion at altitudes between 1000-1500 and 2500-3500 m.
Habitat and ecology. According to Vásquez et al. (2014) this species grows as an epiphyte in the Yungas ecoregion at altitudes between 2500-3500 m. Notes. The specimen cited by Jiménez-Pérez (2011) was not found in the Orchid collection deposited in LPB and we were not able to confirm the occurrence of this species in Bolivia. The characteristics presented above are based on those of Ecuadorian and Colombian plants (Szlachetko and Kolanowska 2019). Type. PERU. Ferreyra 3120 (lectotype, designated by Garay (1978: 200): AMES!, isolectotype: USM; UGDA-DLSz!-drawing).
Habitat and ecology. Terrestrial in Yungas montane humid, and cloud forest, also in montane Tucumano-Boliviano forest, at altitudes between 2380-3000 m. Diagnosis. Species similar to C. pleioneura, but distinguished by 1-veined sepals, lanceolate-ovate petals that are sparsely ciliate in the lower part and by subsessile, suborbicular-obovate lip with apiculate apex.
Etymology. Dedicated to Carla Maldonado, the director of Herbario Nacional de Bolivia, for her great support during our studies in Bolivia.

Cranichis polyantha
Notes. We examined Jimenez 5547 et al. (LPB) cited as reference material for this species in Bolivia by Jiménez-Pérez (2011) and Vásquez et al. (2014) and in our opinion it is not C. polyantha (Fig. 18). The only information about the original collection of this species is the incomplete illustration deposited in AMES. While Schlechter (1920) did not describe any ornamentation on the petals or lip of C. polyantha, both Garay (1978) and Bennett and Christenson (1995) identified this species based on its ciliate petals and lip covered with numerous nodules or papillose-verrucose.

Incertae sedis
I. Jimenez 5547 et al. (LPB!): this specimen was cited by Jiménez-Pérez (2011) as C. polyantha, however, several characters of this specimen do not fit the morphological characteristic of this species (Fig. 18). In Jimenez 5547 et al. the lip is covered with small nodules and the margins of the petals are glandular-ciliate. Currently, with only a single specimen in LPB and discrepancies between the original description of C. polyantha and the treatment of this taxon by Garay (1978) and Bennett and Christenson (1995), we prefer not to describe a new species based on this specimen.

Discussion
As summarized by Mace (2004) and Dubois (2003) effective conservation of species requires a good taxonomic basis. Unfortunately, the number of taxonomic studies that estimate the actual (alpha) diversity of ecosystems is declining (Wägele et al. 2011). Vásquez et al. (2003) note that there is a need for further research on orchids in Bolivia as the actual number of Orchidaceae occurring in this country is most probably much higher than currently recorded. In this paper we provide the most complete data on Bolivian Cranichis published so far. The species characteristics and dichotomous key presented will simplify the process of identification of Cranichis by local botanists and improve the quality of regional checklists.
Based on this study, details of perianth segments are the most useful diagnostic characters in Cranichis, however, the proper identification of some taxa is difficult without information about leaf petiole size (C. longipetiolata, C. polyantha) or inflorescence shape (C. lehmannii, C. cylindrostachys). Only two Bolivian Cranichis (C. garayana, C. pulvinifera) are characterized by a distinctly 3-lobed lip with irregularly erose to erose-lancinate margins. The lip form and ornamentation, together with shape, size and ornamentation on the margins of the tepals, can be used to identify most species in this genus in Bolivia. Petals of Bolivian Cranichis are 1-veined, whereas sepals can be 1-, 2-, 3-or 5-veined. Tepals can be glabrous or variously ciliate, papillate or pilose. While extensive studies on Cranichis (e.g. Kolanowska and Szlachetko 2014;Szlachetko and Kolanowska 2019) indicate that the number of veins is constant within a species we noted a variation in venation in Bolivian populations, which correspond to C. badia. There is a possibility that they represent an undescribed species of Cranichis, but we prefer not to delimit any new species based solely on the number of veins.
Similar to many other new species of orchids (e.g. Averyanov et al. 2015;Baquero et al. 2018;Lin et al. 2020) the new taxa described here are based on single specimens. This is not surprising as numerous tropical orchids are local endemics and their geographical ranges are often limited to small patches of forests or single valleys (Koopowitz 1992;Vermeulen and Lamb 2011). Among the numerous factors that affect the geographical distribution and diversity of orchids (Dodson 2003), local radiations resulting in the evolution of numerous species of orchids in relatively small areas seems to be the most important (e.g. Jost 2004). Describing new species based on limited data is obviously risky as there is no information on the intraspecific variation in such taxa. However, considering the ongoing loss of habitats for orchids (Wraith et al. 2020) it is important to identify novel orchids before they go extinct (Swarts and Dixon 2009;Vermeulen et al. 2014), even though based on incomplete data on their morphological variation.

Conclusions
Here we present synopsis of Bolivian species of Cranichis. Morphological characteristics of all the species together with the illustrations of the perianth segments and the identification key will be useful for local botanists collecting orchids. The proper documentation of the distribution of rare and endangered orchids in Bolivia will help in the establishment of more advanced nature management programs.
The occurrence of 12 species of Cranichis, including two new species and two new records, in Bolivia was confirmed. We did not validate the presence of C. diphylla, C. lehmannii and C. muscosa in this country. Moreover, in our opinion, the previously published Bolivian record for C. polyantha is doubtful and the specimen collected is an undescribed species. However, due to incongruities between the original description of C. polyantha and concept of this orchid presented by Garay (1978) and Bennett and Christenson (1995), we prefer not to delineate a new taxon.