Aldama macbridei (Heliantheae: Compositae): notes on its distribution and vulnerable habitats in central Peru

: Aldama macbridei (S.F.Blake) E.E. Schill. & Panero (Heliantheae: Compositae), endemic to Peru is updated in terms of its distribution in the Central Andes. Also presented is a brief description of the species and the environments it inhabits. It is proposed its conservation status according to IUCN Red List categories be upgraded to ‘Near Threatened’ (NT).

ISSN 0974-7907 (Online); ISSN 0974-7893 (Print) The genus Aldama La Llave (1824: 14) (Heliantheae, Compositae) is native to tropical and subtropical areas and comprises 118 species extending from southwestern North America and Mexico to South America (Schilling & Panero 2011;Magenta et al. 2017). In Peru, the genus is represented by eight species (Schilling & Panero 2011) mainly distributed in subtropical dry and humid montane forests across the Andes.
During ongoing floristic studies in archaeological sites in the boundaries of the Alto Marañon region in Central Peru (Montesinos-Tubée 2016, 2017, some interesting specimens of Aldama were collected. These plants occur on rock crevices and steep slopes in the boundaries of Pasco and Huánuco departments at 2,300-2,450 m elevation. After examination the specimens were identified as Aldama macbridei (S.F.Blake) E.E.Schill. & Panero, which is endemic to Peru (Beltrán et al. 2006) and has not been recorded in the studied region so far. The habitat of the type locality, near Huacachi, Mito (Blake 1926), has been modified by agriculture conversion, forestation with exotic species, and burning of the slopes (Image 1). The objective of this study is to present a brief description of Aldama macbridei along with photo plates and other relevant information, to facilitate the correct identification of this species and define its conservation status in the light of present field observations and the diminishment of native ecosystems.

Materials and Methods
This contribution is the result of a review of the published bibliography, field work in southern Peru, and the revision of Peruvian herbarium specimens. Additionally, digital specimens from USA herbaria were studied. Herbarium acronyms follow Thiers (2020 (South America) and specimens of Aldama macbridei were collected, identified using relevant literature (Magenta et al. 2017;Pruski & Robinson 2018), and also compared with specimens from different herbaria (CPUN, COL, F, GH, HSP, HUT, K, MH, MOQ, OXA, TX, US). All voucher specimens are deposited in the herbaria of Cajamarca University (CPUN), Michael Dillon Institute (HSP), La Libertad-Trujillo National University (HUT), Moquegua National University (MOQ), and San Marcos National University (USM). Pictures of living individuals are presented.

Sampling strategy
After the study of herbarium specimens from Huánuco (Macbride 4078), Huancavelica (Tovar 1884), and Ancash (Cerrate 2135 & 3746), several expeditions to those provinces and neighboring areas allowed us to collect individuals from a population located 60 km from the type locality of Aldama macbridei. Based on data from sheet labels we were able to contrast the current variability of some morphological characters in the field, and to observe the typical habitats and ecological features for this taxon. Early and reproductive stages were measured for vegetative characters to assess phenotypic plasticity associated with soil characteristics and slope inclination. Juvenile, sexually immature but well-developed plants (>1.5 m tall) and adults, sexually mature plants, and flowering individuals were characterized at least once. An estimation of the number of individuals composing the population sampled was done. The species has been assessed for its conservation status based on the 14 th version of the IUCN Red List (IUCN 2019). The locality sampled was recorded by Garmin Global Positioning System, allowing the first georeferenced population of Aldama macbridei.

Results and Discussion
The description of the species with notes on its distribution, phenology, ecological aspects, details of specimens examined and conservation status along with colour photographs to facilitate accurate identification are given below. Holotype: 4078, 20.v.1923-1.vi.1923 Muña, at about 1,980 m, coll J.F. Macbride (F-535145!). Isotypes: GH barcode 00014012 image!, S-R6483 image!, US-1191485 image!.
Flowering: Flowers and fruits were observed between March and May.
Ecology: This species was found on the lower mountain slopes close to the Huertas river, tributary of the Huallaga river, between the cities of Ambo (Huánuco) and Yanahuanca (Pasco) at an altitudinal range of 2,320-2,410 m. The species inhabits the tropical dry low montane forest (bs-MBT, MINAM 2009), considered a life zone located in the Meso-Andean region and characterized by the predominance of mountainous steep slopes. The prevailing climate is characterized by its dryness during several months of the year. The total annual precipitation fluctuates between 500 and 600 mm. The vegetation cover is deciduous as well as evergreen shrub species, and there is evidence of fire occurrence (mostly by anthropic action), influenced by the dominance of grasses. The following species were observed in the environment of Aldama macbridei in the boundary of the Huánuco-Pasco departments: Caesalpinia spinosa The other specimen corresponds to the Colcabamba district, Tayacaja province, Huancavelica department, in humid montane forests (bh-MT, tropical montane humid forest), at 2,300 m. An altitude of 1,980 m is indicated on the label of the type specimen, in Pachitea, Huánuco. Considering new collections, it is therefore concluded that the altitudinal distribution range for Aldama macbridei is from 1,980 to 3,060 m in tropical dry low montane forests (Figure 1).
Distribution: Central Peru, new to Ancash, Huancavelica and Pasco departments. Prospections on herbaria out from Peru (example COL) allow us to reaffirm that the taxon does not surpass the Peruvian territory and is endemic to the mountains of the Central Andes. According to our ongoing expeditions in these geographic high-altitude systems, the species distribution boundaries lie between Huánuco province to the north, and Huancavélica province to the south, and is limited to the high altitude plateaus or Andes mountains.

Journal of Threatened Taxa | www.threatenedtaxa.org | 26 February 2022 | 14(2): 20666-20671
Aldama macbridei: notes on its distribution and habitats in central Peru Conservation status: With nearly 724 endemic Composite species, Asteraceae is the second biggest family in terms of endemicity, in Perú . Endemism is a significant attribute of any taxon with reference to its restricted distribution, and endemic species of Peruvian Andes mountains located between Huancabamba deflection, an important biogeographic boundary, and Atacama Desert, hold immense significance. An assessment of their geographical distribution within remote Andean areas is of great conservation concern. Assessments are always done using the best available information, however, there is a dearth of knowledge in the case of the distribution pattern for many high-altitude endemic species, especially those in some Andean mountains with difficult access, as those explored as part of the ongoing prospection of Asteraceae from Perú.

Montesinos-Tubée & García-Yanes
The study by Beltrán et al. (2006) regarding conservation status on Peruvian Asteraceae has provided valuable information for most of endemic Composites in the country. In the present survey, an attempt has been made to assess the population and conservation status of one of the species omitted from this work (Aldama macbridei), because of the scarce exploration of some remote Andean areas, as those considered and sampled here.
Also, a perusal of herbarium consultation in local (CPUN, HSP, HUT, MOQ, OXA, USM, TX) and international herbaria has revealed interesting new information about the species distribution. A new record from Huancavelica province (Tovar 1884) allows us to broaden the current knowledge for the distribution of the species, thought to be limited to Andean high-altitude plateaus located to the North of Lima, the Capital city (provinces of Ancash, Huánuco, and Pasco).
According to the criteria and categories of IUCN (2019), it is proposed as 'Near Threatened' (NT) following Red List criteria. This taxon has a reduced distribution area (less than 10,000 km²). For the locality sampled, less than 500 individuals were counted for the whole population at this site. Only four other populations are known, and the absence of other collections allow us to consider that the species may be restricted to the localities referenced in this work. Nevertheless, one of these populations is located near the Huayhuash reserve, in a private protected area (Sernanp 2021), so the category NT is defined preliminarily, to move to an eventual threatened category (ex. EN B1-b) if future assessments of population dynamics firmly establish a high risk of extinction. Suitable habitats for Aldama macbridei are regarded as near threatened because of slope burning in all the areas where its occurrence is known. Also, agriculture expansion, changes in annual rainfall, landslides, and forestation with exotic species are quite common ongoing processes outside the protected area where one occurrence is registered. These factors, together with exploitation of natural resources (especially mining in Ancash, Huanuco, and Pasco provinces) and the expansion of roads (MTC, 2020) due to the explosive demographic growth of Lima's vicinities (the capital city) may all potentially reduce the current extent of Aldama macbridei's populations. Interestingly, several degraded areas with steep slopes (the current habitat for Aldama macbridei, ex. Figure 3B) documented during our expeditions, present a potential for reforestation with native species for watershed protection purposes. Notes: Aldama macbridei, was originally described by Blake (1926) under the species Viguiera macbridei S.F.Blake from Pachitea region, Huánuco province. According to Schilling & Panero (2011), Aldama macbridei was better placed into Aldama group than within Viguiera traditional concept. Aldama macbridei is allied to Aldama linearifolia (Chodat) E.E. Schill. & Panero (2011: 324), differing by the glabrous stems, narrower leaves, glabrous pedicels, larger phyllaries and ray limbs, and by the distribution of the latter in Brazil and Paraguay. Aldama macbridei also differs from Aldama linearis (Chodat) E.E. Schill. & Panero (2011: 324), another similar species, by its relatively shorter leaf size, hispidolous pubescence of leaves, broader phyllaries, shorter capitules and by the distribution of the latter in Mexico. Lastly, it differs from Aldama tenuifolia, (Gardner) E.E. Schill. & Panero (2011: 325), a brazilian representative of the genus, by the narrower leaves, glabrous underside of the leaf blades, glabrous stems, and pedicels.

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