Revision of Liparis (Orchidaceae, Epidendroideae, Malaxidinae) in Brazil

Abstract The presence of Liparis occurring in Brazil was revised, resulting in three taxons confirmed in national territory. Nine lectotypifications and six neotypifications, together with L. inundata being demoted to a synonym of L. nervosa, are proposed. Species can be distinguished by the leaf blade, the number of leaves per pseudobulb and the presence of calluses in the lip. From those, only L. cogniauxiana is endemic to the country, being restricted to the Cerrado biome. Liparis nervosa occurs in all Brazilian biomes and is the only one registered in the Pampas and the Caatinga, while L. vexillifera occurs in the Atlantic Forest, Amazon and Cerrado biomes. According to the IUCN criteria, L. cogniauxiana, L. nervosa and L. vexillifera are in the ‘‘Least Concern (LC)’’ category due to a broad distribution, the number of occurrences, presence in protected areas and low pressure from indiscriminate collecting.


Introduction
Orchidaceae is one of the richest plant families (Chase et al. 2015) and is well represented in Brazil, with 251 genera and approximately 2,500 species, of which almost 1,500 are endemic to the country (BFG 2018).Although Liparis Richard (1817: 39) is a cosmopolitan group with more than 300 species (Cameron 2005), only three are traditionally recognized as occurring in Brazil (Santos & Smidt 2020).
Liparis was described in 1817 by Louis-Claude Marie Richard, with Ophrys loeselii Linnaeus (1753: 947) as the type species, based on a specimen from Sweden that honors the plant collector Peter Johann Loesel, a german botanist from the 1600s who studied the Prussian flora (Loesel 1703).Linnaeus described this species as plants with bifoliar and lanceolate leaves and glabrous inflorescence with 5 to 8 flowers, slightly reflexed petals, and a strongly ovate lip.The most complete taxonomic approach Rodriguésia 74: e00192023.2023 that classifies Liparis at the infrageneric level was carried out by Garay & Romero-Gonzalez (1999), who proposed a key for identifying the taxa.The authors reported four subgenera and 19 sections.
Liparis was historically split into different smaller groups based solely on morphological characteristics, and some of the subgenera and sections can be interpreted as separate genera according to some authors (du Petit Thouars 1809; Pfitzer 1887; Margońska & Szlachetko 2001;Jones & Clements 2005); nonetheless, these classifications rarely or never represent the evolutionary pattern for the group (Cameron 2005;Pridgeon et al. 2005).Since there is much historical confusion concerning the Liparis taxonomy, it is better to not adopt an infrageneric classification until a more robust phylogeny is proposed for the Neotropics (Pridgeon et al. 2005;Radins et al. 2014).
This research aimed to revise the Liparis species recorded in Brazil.We present taxonomic notes, complete descriptive comments with ecological information, diagnoses, illustrations, photographs, identification keys, distribution maps and an assessment of the conservation status of these species.

Results and Discussion
A total of 767 exsiccates were studied, 736 from specimens collected in Brazil and 31 from other countries.A total of 50 vouchers belong to Liparis cogniauxiana F. Barros & L.R.S. Guimarães (2010: 31), 562 of Liparis nervosa (Thunberg 1784: 814) Lindley (1830: 26) and 124 of Liparis vexillifera Cogniaux (1896: 289).From those, only L. cogniauxiana is endemic to the country, being restricted to the Cerrado biome.Liparis nervosa occurs in all Brazilian biomes and is the only one registered in the Pampas and the Caatinga, while L. vexillifera occurs in the Atlantic Forest, Amazon and Cerrado biomes (Fig. 1).
Liparis cogniauxiana is characterized by its small size with a terrestrial habit and two or rarely three plicate leaves emerging from the lateral or apex of the entirely or mostly aboveground pseudobulb.
It can be recognized and distinguished from the other two species of the genus in its vegetative morphology, by the greater compactness between the pseudobulb and leaves with a short petiole, and its flowers, by the two inconspicuous calluses at the base of the lip.This species resembles Liparis nervosa, being distinguished by a tgetative size of 51-149 mm instead of 92-520 mm in length, by the presence of two or rarely three leaves per pseudobulbs, and by the rounded calluses on the lip.
Liparis cogniauxiana is endemic to the Cerrado biome, usually occurring in low-altitude areas within the forest formation of dry woods, but occasionally can be found exposed to the sun in the formations of dry or rupestrian fields.It blooms from December to April and is fertile from the beginning to the end of summer.With an extent of occurrence (EOO) of approximately 1,402,367.520km², an area of occupancy (AOO) of approximately 200,000 km², together with several records inside protected areas, this taxon falls into the category of ''Least Concern (NT)''.
The Cymbidium bituberculatum protologue mentions a collection by J. Cooper from Nepal that could not be found in any herbarium, and the information in the text is insufficient to confidently determine if it was ever herborized.In the same work from Hooker (1824), an illustration based on the specimen used to describe his species is presented; hence, it is designated as the lectotype here.
The collection of ''Ridgway J. 169, May of 1834'' used in the description for Liparis guineensis could not be found and is probably lost; hence, the illustration based on the same exemplar (Lindley 1834) is here designated as the lectotype.
The identity of Liparis elata var.purpurascens is uncertain.The protologue lacks indication of an original material, and the only two pieces of information given are -''purple leaves and erect bracts''.Although the diagnosis of this taxon as a variety of Liparis nervosa is unclear, for taxonomical balance, we still opted to designate a collection as the neotype: ''R.P. Lyra-Lemos 4618'' (MAC11091), as it bears the purplish leaves mentioned in the protologue.
There are three syntypes of Liparis kappleri (AMES00052492; AMES00271895; P00347774).As no holotype is indicated among these duplicates in the protologue of the species and the material deposited at P ( 00347774) is of better quality, it is designated here as the lectotype.
The Liparis odontostoma holotype collection made by Hooker J.D. in the Sikkim state region of India is probably lost, and as no other original material seems to exist, we choose to designate the collection of Hooker J.D. without number (K000387773) from Mount Khasi in the Meghalaya state region as the neotype, due to it being well preserved and found in a nearby area in India, representing the taxon accordingly.
There are multiple syntypes of Liparis eggersii deposited in distinct herbariums.Therefore, we here designate the collection of GOET (008575) as the lectotype, choosing it among the duplicates due to the good condition of the exsiccate, which presents complete inflorescence with fruits and flowers.
The description of Liparis elata var.latifolia by Ridley (1886) emphasizes broad leaves as a morphological characteristic for recognizing the species.The protologue indicates two distinctive collections as types, with multiple duplicates spread among different herbaria.The collection of Balansa B. 4542 from Paraguay presents specimens with narrower leaves than the collections of Wright C. 1495 from Cuba, thereby being ruled out as a lectotype.Among the duplicates of Wright C. 1495, the material deposited at BM ( 000074263) is chosen to be designated here as the lectotype due to the good condition of the exsiccate -with complete vegetative and reproductive parts as well as for displaying morphological characteristics closely related to the original description of the taxon.
The Liparis elata var.rufina protologue indicates two distinguished materials that are herborized in the same exsiccate, while the collection of Morson without number (K000242155) comprises only an inflorescence and a drawing of a flower belonging to one specimen.The collection of Barter without number (K000242156) is complete -composed of vegetative and reproductive parts from two individuals, in addition to the drawing of a flower; hence, it is here designated as the lectotype.
The Liparis bituberculata var.khasiana holotype is lost, and no other original material seems to exist; thus, we designated the collection of Griffith W. 5068 (K000387771) as the neotype, as it supports the characteristics described by the author and was also collected in India.This same exsiccate includes another collection (K000387770) identified as L. bituberculata var.khasiana; however, this one lacks information about the collector, and the specimen could even belong to another species, as it does have some unique features such as an elongated stem and the absence of pseudobulbs; therefore, it should be disregarded.
Three duplicate collections of original material belonging to Liparis elata var.longifolia are deposited at P (P00338287; P00338288; P00338289).Even though they are all in good condition, we opted to designate the collection of P (00338287) as the lectotype here, as it is the only one with flowers and fruits in the same exsiccate.
While studying Liparis nervosa we noticed that some plant collections had smaller sizes and oblong-lanceolate leaves.These exemplars with these morphological features generally inhabit wetlands in open fields, with some exceptions in the Amazon Forest, where this morphotype (Fig. 3a) is also found in the forests near the Rio Negro River.
The variations in vegetative morphology of these specimens have caused taxonomic controversy, even though the shape and size of floral parts are not different from those of common L. nervosa.This morphotype was recognized previously as Liparis elata var.inundata (Barbosa Rodrigues 1877;Cogniaux 1896;Hill 1926), a synonym of L. nervosa that was recently elevated from the variety position to species status as Liparis inundata by Pansarin et al. (2020).Nonetheless, the difference in phenology within populations was used as a comparative feature between this morphotype and a common L. nervosa.However, we recommend caution when using this characteristic since populations may differ in their flowering season depending on their occurrence; these varieties could be attributes of the habitat itself, driving populations to flower at different times of year.
For now, we prefer to keep L. inundata as a synonym of L. nervosa since the morphological and ecological characteristics used to discern them are not sufficient, and it is not hard to find plants with intermediate morphology (Fig. 3b), which can cause even more taxonomical instability in this taxon.One future approach could be to manually cross-pollinate these different morphotypes, monitor the offspring generated between populations, and compare the morphological characteristics of the different individuals generated.
Liparis nervosa is characterized by its highly variable vegetative size and terrestrial habit, but occasionally, it is found growing on organic matter accumulated between tree trunks or rocks.Mature individuals always have more than two leaves, which are deciduous and show rapid growth after falling, emerging from the side or apex of the entirely or mostly aboveground pseudobulb.The flowers are usually fertile in succession in a spiral conformation from the base of the inflorescence to its apex.
It can be recognized and distinguished from the other two native species by its usually larger size and many leaves, and its pseudobulbs always bear long and thick roots.The flowers are similar to those of Liparis cogniauxiana but can be distinguished by the two tooth-like calluses presented at the base of the lip.
Liparis nervosa can be found in all Brazilian biomes, flowering from January to December.It commonly occurs in lowland forests, montane forests, and marshes but can sometimes be exposed to the sun in open flooded fields or on roadsides near forests.With an extent of occurrence (EOO) of approximately 6,702,407.731km², an area of occupancy (AOO) of approximately 2,128.000km², and a presence in all Brazilian biomes, the taxon falls into the category of ''Least Concern (LC)' cylindrical,, ellipsoid or rarely oblongoid; covered by white, green or brown deciduous foliaceous sheaths.Leaves 47-160 × 10-83 mm, green, one per pseudobulbs, several layers of a sheath-like petiole 8-58 mm length; lamina conduplicate or flat, sometimes involving the floral stem, coriaceous, oblonglanceolate, lanceolate, rarely elliptical, margin entire or undulate, apex acute, rarely obtuse.Inflorescence 25-163 mm raceme; floral bracts in the base of the pedicels, acuminate.Flowers resupinate; yellow or green, sometimes purplish or reddish only in the lip; pedicels 3-8 mm length; ovary 2-7 mm length.Dorsal sepal 6-8 × 1-2 mm, oblong or oblonglanceolate, margin entire and revolute, apex obtuse or slightly acute.Lateral sepals 5-7 × 0.5-2 mm, free, oblong or oblong-lanceolate, margin entire and revolute, apex obtuse or slightly acute.Petals 5-9 × 0.4-1 mm; linear; margin entire and revolute; apex obtuse.Lip 6-7 × 4-6 mm, trilobate, glabrous; base with two longitudinal calluses that extend up to the apex of the lip, with one internal robust vein; lateral lobes extending from the base up to the middle of the lip, rounded; mid-lobe ovate or rarely obovate, slightly reflexed, margin entire, slightly undulate near the apex; apex rounded, rarely emarginate.Column 4-5 mm length, slightly arched; foot short, apex winged; anther green or yellow.Pollinarium with two ovoid, bipartite pollinia.

Figure 1 1 .
Figure 1 -a-d.Distribution of Liparis -a.occurrence of all species in Brazil and indication of the country's position in South America; b. occurrence of Liparis nervosa; c. occurrence of Liparis cogniauxiana; d. occurrence of Liparis vexillifera.

Figure 4
Figure 4 -a-j.Illustration of Liparis nervosa -a.habit of the morphotype previously called Liparis inundata; b. habit of the intermediate morphotype between L. inundata and common Liparis nervosa; c. habit of common L. nervosa; d. frontal view of the flower; e. lateral view of the flower; f. dorsal sepal; g. petal; h.lateral sepal; i. lip; j. lateral view of the column attached to the ovary (a.G.A. Black 2749, 2771; b.G.T. Prance 15906; c, e, d, f, g, h, i, j.T.F.Santos 60).

Figure 5
Figure 5 -a-h.Illustration of Liparis vexillifera -a.habit; b. frontal view of the flower; c. lateral view of the flower; d. dorsal sepal; e. petal; f. lateral sepal; g. lip; h.lateral view of the column (a-h.T.F.Santos 350).