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Abstract Tecoma stans is a widely distributed tall ornamental shrub in the plains of Indian subcontinent and is considered an invasive species across Argentina, Australia, South Africa, Pacific Islands and tropical regions of Asia. Besides having an ornamental significance, T. stans has been extensively investigated for its pharmaceutical applications as a source of bioactive compounds. In addition, the shrub is cultivated commercially as a potted flowering plant. We believe that T. stans, being a hardy, invasive and aggressively growing species, holds a considerable potential and a promising solution for re-greening waste and degraded lands outside its invasive range, due to its wider adaptability and drought tolerant characteristics. The shrub is an excellent source of pollen and nectar, that attracts diverse insect-pollinators and several species of birds. The prudent plantation of this shrub has the potential to restore the ecology of barren landscapes, that can change its perspective of ‘being invasive’ to ‘being ecologically healthy’ across the tropical, semi-arid and subtropical regions worldwide. This paper reviews the current updates on ecology, life cycle including morphology, plant growth characteristics, flowering phenology, reproductive biology, breeding system and fruiting of T. stans. In addition, details on insect-pollinator diversity and natural regeneration potential have also been discussed, besides highlighting its therapeutic and landscape use.

The precise knowledge of the seasonal influence on phenology, timing and duration of different growth stages (phenophases) exhibited in a life cycle of a plant is crucial for undertaking several crop management decisions. The reproductive growth stages hold a particular relevance in this regard that conveys a ‘seasonal shift’ and also a ‘shift’ in the timing, duration and intensity of vegetative and reproductive growth stages due to subnormal micro-climate induced by climate change. The present study investigates the phenological growth stages of Tecoma stans - a drought tolerant, yellow flowering shrub with a versatile use for urban greening and beautification. Till date, the phenological characteristics in T. stans have never been codified or described so far. The study was undertaken with an objective to codify the seasonal change in the phenological growth stages of T. stans using bi-numeric BBCH (Biologische Bun-desantalt, Bundessortenamt und Chemische Industrie) scale under subtropical climatic conditions of North West India. The experiment was planned on T. stans planted as a shrubbery block in a randomized block design layout. The distinct phenological growth stages of this shrub were represented through photographs. The year-round phenological calendar was also evolved exhibiting the time lapse of different phenophases along with their frequency and intensity of occurrence. Seasonal variation in mean temperature and precipitation markedly affected the phenological behavior of T. stans that exhibited seven major phenological growth stages namely, seed germination, leaf development, elongation of lateral shoots, inflorescence emergence, flower development, pod development and maturity of seed. The investigations undertaken are of vital interest to the urban landscape managers for the selection of species not only based on their aesthetic attributes but also to consider their functionality associated with the site-specific conditions. In addition, the salient findings will help deepen the understanding of weather-induced ‘eventful’ interactions of pollinators and flowers of T. stans that greatly benefit in a symbiotic manner, ensuring the survival and perpetuation of the species. The newly developed scale provides a unified standard for describing and identifying the phenological growth of T. stans that can potentially be utilized as a reference scale for undertaking future phenological studies.

The phenological studies of tree species is a potential tool to develop a keen observation for monitoring the gradual impact of climate change on biology of trees, manifested through variation in timing and duration of different phenological events in their life cycle. The documentation of these phenological growth stages reflect upon the implications for their responsiveness to seasonal variation in climate and potential utilization for the benefit of mankind. Pertaining to the immense significance of phenology, a study was conducted to document different growth and developmental stages in Moringa oleifera Lam. referencing to the BBCH scale (Biologische Bundesantalt, Bundessortenamt und Chemische Industrie), supplementing with significant Landmark stages (developed by the authors) under the subtropical conditions of Punjab state, India. The observation and the analysis of the growth stages in M. oleifera depicted asynchronous growth patterns exhibiting juvenile, vegetative and reproductive developmental stages within an individual tree canopy. These phenophases appeared simultaneously and were designated numerical values corresponding to principle growth stages (0–9) and secondary sub-stages (0–9) reflecting their relative intensity of occurrence. The novel landmark scale proposed for M. oleifera, defines the optimum stage(s) for its utilization such as tender leaves for culinary purpose; mature leaves for processing for manufacturing of fortified food products and herbal medicines; and immature pods for utilization in culinary preparations. The landmark stages proposed in M. oleifera reflect its immense significance for introducing as an edible tree species in Urban Food Forests as a source of nutrition besides offering other multi-functionalities of ecological, landscaping, esthetic and spiritual aspects.

The genetic diversity and growth dynamics of fifty-three half-sib families of eleven provenance sources and one bulk seed mixed population of fast growing forest tree species i.e. Melia azedarach were studied at two stand ages viz., fourth year (mid-rotation) and eighth year (end-rotation) to determine the selection stage in northern India. Significant variations were reported between and within seed provenances in all growth characters at both rotational ages. The broad sense heritability was higher at mid-rotational age. This revealed the growth is genetically controlled but with the time environmental effects escort the growth pattern. Growth pattern was different at each stand age. Growth is diameter dependent and the pattern was crown growth type. Families maintained their superiority over the time for tree height, basal diameter and diameter at breast height, which indicated a strong potential to identify good performing families for future plantation program. This study concluded that early stage selection is appropriate that later stage selection for all parameters studied except clear bole height that is much influenced by management practice and environment factors also. Neighbor-joining clustering with similarity index revealed that it is not necessary that the families, originated in one region were distributed in one cluster, indicating that families with same geographic origin could have undergone changes for different characters under selection.