Characterisation of Three Flower Colour Morphotypes of Tecomella undulata (Rohida) Based on Density, Distribution, Phenology and Morphological Traits in Rajasthan

Tecomella undulata (Sm.) Seem., commonly known as Rohida, is one of the most valuable indigenous timber species of the Indian Thar Desert and adjoining semi-arid regions. The species belongs to the family Bignoniaceae and is well adapted to harsh arid climatic conditions (Kritikar and Basu 1993; Nadkarni 2000). Due to overexploitation for wood and medicinal uses, the species is categorised under endangered section in Rajasthan. Besides its importance as quality timber, it contributes significantly to biodiversity conservation, agroforestry systems, and restoration of degraded landscapes thus considered as key stone species of Rajasthan (Kumar et al, 2008). Beyond its importance as a timber species, T. undulata has considerable relevance to agroforestry and range-management systems in the arid and semi-arid regions of Rajasthan. Its ability to survive under low rainfall, high temperature and poor soil conditions makes it a suitable tree component for dryland-based agroforestry and silvopastoral systems. The species can contribute to the diversification and resilience of production systems while providing tree-based ecosystem services and supporting the restoration of degraded lands and rangelands. Incorporation of well-adapted and genetically superior T. undulata planting material into agroforestry and restoration programmes may therefore help in improving the sustainability of land-use systems in the Thar region. Knowledge of its natural distribution, phenological behaviour and morphological variation is particularly important for identifying suitable populations and morphotypes for conservation, enrichment planting and future agroforestry and range-management interventions. This species exhibits considerable phenotypic variation, particularly in flower colour (Fig 1), canopy architecture, and reproductive characteristics (Chakrawati and Chand, 1975; Negi et al., 2011). Due to variation in flower colour, the species is recognised as State flower of Rajasthan (Fig 1) (Chal et al. 2011). Phenological studies particularly flowering and fruiting are vital to develop viable conservation and breeding strategies. Thus knowledge on distribution and phenological pattern of any species is an important approach for improvement and breeding programmes and conservation planning (Beniwal, 2005). Similarly, variability in pod, seed, and leaf traits is also an important step because it serves as important criteria for selecting superior genotypes for quality planting material and genetic improvement. Despite the ecological and economic importance of Rohida, no information is available regarding comparative phenological performance among different flower colour morphotypes. Therefore, to the best of my knowledge present study was carried out to record flowering and fruiting pattern, evaluate variability in pod, seed, and leaf characteristics, and document density and distribution among three different flower colour morphotypes of T. undulata in Rajasthan.

Novelty and Contribution of this Study: While earlier studies have documented morphological variation in T. undulata (Chakravarty and Chand, 1975; Negi et al., 2011) and molecular differentiation among flower colour morphotypes (Kaur et al., 2018; Meena et al., 2025), no study has comparatively assessed the phenological performance of the three flower colour morphotypes across reproductive seasons. This study makes three specific contributions. First, it provides the first comparative account of flowering and fruiting patterns among orange-, red-, and yellow-flowered morphotypes of T. undulata monitored over two consecutive reproductive seasons. Second, it integrates density and distribution data from 14 natural populations across eight districts with morphological and phenological data from a single representative population, thereby linking population-level patterns with individual-tree performance. Third, it reports effect sizes for morphological traits and interprets phenotypic differences cautiously in relation to prior molecular evidence, providing a basis for conservation and quality planting material programmes. By distinguishing between observed phenotypic differences and confirmed genetic differentiation, the study aims to guide future integrated research on this endangered arid-zone tree.