Morphology characteristics of orchids species in Bukit Barisan, Bengkulu province

The species orchid is one of the rich local genetic resources of Bengkulu Province. Information on the diversity of orchid species in Bengkulu has not been widely disclosed, so characterization is needed. This study aims to identify and characterize orchid species based on morphological characters. The study was carried out in Bukit Barisan, Central Bengkulu, Kepahiang, Rejang Lebong and Lebong from April to December 2018. The orchid data collection was carried out by exploration methods and direct observation of orchid plants in situ and exitu. In-situ observations were made on all orchid species found in their habitat and were flowering or fruiting, while the external observations were made on orchids that were not flowering and bearing fruit in their habitat. The samples of these orchids are collected and maintained beforehand until they grow flowers and fruit. Observations were made on morphological characteristics, namely the growth pattern of stems, pseudobulbs, leaves, flowers and fruit. Determination of the types of orchids identified in accordance with orchid guidelines. There are 15 genera consisting of 34 types of orchids with various forms of stem growth, pseudobulbs, leaves and flower colors.


Introduction
Indonesia is one of the biodiversity countries which has the largest tropical rainforest in the world with a very high diversity of genetic resources including orchids. Orchids are among the fifth most abundant plants in the world and grow as epiphytes and terrestrial [1]. The number is estimated at more than 26,000 species and 5,000-6000 species are in Indonesia. Puspitaningtyas [2] mention 1,327 species grow on the island of Java and the rest grow on the islands of Sumatra, Kalimantan, Sulawesi, Irian Jaya, and other islands. Bengkulu Province is one in Sumatra which is famous for its Bukit Barisan with a diverse topography in which there is a lot of high biodiversity and one of them is natural orchids or forest orchids. Tropika et al [3] found 1118 species of orchids in the Sumatra region, 458 of which are endemic to Sumatra, especially in mountainous areas in the Bukit Barisan. These orchids are known as species orchids. Natural orchids or species orchids are orchids that have not undergone a cross that are still living naturally in their natural habitat. The wealth of natural orchids is widely distributed in forest areas, topography or other vegetation. In Bengkulu, the diversity of orchids is estimated to be reduced or threatened with extinction in line with forest destruction due to forest burning, land use change for road construction and settlement. On the other hand, orchid diversity is a very valuable asset and will not be valuable if not utilized. So far, the information on the diversity of orchids in Bengkulu has not been   Optimal orchid growth will have a positive impact on the flowering process. The distribution and preservation of orchid genetic resources in Bukit Barisan is influenced by climate [5].The recorded temperatures ranged from 23.94 and 24.06 degrees Celsius. Orchids grows at an altitude of 0-2000 m above sea level, the temperature needed for orchid growth ranges from 21-35 0 C [6]. Furthermore there are two main factors that affect orchid growth, namely intrinsic factors and extrinsic factors [7]. Intrinsic factors that influence the flowering process include: genes, endogenous hormones, and plant age. Meanwhile, extrinsic factors that influence the flowering process include: light, temperature, humidity, nutrient availability, and external induction of phytohormones. All of these factors are interrelated to support optimal plant growth.

Identification and characterization of local orchids
Based on the identification results, it was found that the orchids found were very diverse, namely 34 species, most of which were 91.17% of the epiphytic orchids and 8.82% were ground orchids ( Table 1). Sumatra is one of the regions rich in epiphytic orchids. Epiphytic orchids are orchids that are attached to trunks, branches or branches of living or dead trees as their living substrate. The functional roots are dangling, while the roots that stick to the media (substrate) only function as an adhesive root, namely to hold the plant in its position [8]. The observation results showed that the host trees which have a rough surface of the bark are the places where the efifit orchids attach.Fardhani et al [9] suggest that tree species with these characteristics affect water and nutrient storage. Furthermore, the identification results (Table 2) showed that orchids have two types of growth, monopodial (5.8%) and sympodial (94.12%).
According to Rosanti [10] monopodial orchids are orchids that have a main stem that continues to grow upward (vertically) indefinitely. Leaves will increase steadily from the tip of the stem throughout its life. This species is devoid of rhizomes and pseodobulbs, and usually grows aerial roots along the length of the stem. Flower stalk grows from the side of the stem (axillary). If the tip of the stem is damaged by rot or cut / cut, a new stem will grow from the side of the old stem and leaves will grow from the new stem. Sympodial orchids are orchids that have a main stem that is composed of annual segments. This type of orchid has a pseudobulb stem (pseudobulb). The growth of the ends of the stems is limited, stem growth will stop when the upward growth has been maximized. A new stem emerges from the base of the previous main stem.
Based on the observations obtained 15 genera consisting of 34 species. The orchids found have their own unique character, starting from the shape of sepals, petals, labellum and different colors. Efipit orchids have deep roots and hang in the air. The roots attach to both living and dead trees and have a rough surface [11]   10 Tabel 3. discovered that the orchid flower has a very large variety of flowers. A unique and attractive form is a genetic asset asset that can provide economic value if managed properly [12]

Conclusion
There is a diversity of growth types, bulb shape, shape, size, leaf and flower shape and color.