Morphological Characterization of Certain Ornamental Cacti Genera Suitable for Tropical Climatic Regimes

Cacti are ornamental, perennial, succulent and slow growing plants, especially known for their drought
tolerant characters (xerophyte). The wide range of forms, shapes, and sizes of their stems and
flowers and certain specific characters viz., areoles, spines, glochids etc. make this group of plants
unique in the indoor as well as in outdoor gardens, parks and landscapes. An experiment on
assessing cacti belonging to different genera for their morphological traits was conducted at the
Department of Floriculture and Landscaping, Horticultural College and Research Institute, Tamil Nadu
Agricultural University, Coimbatore during 2017-2018. In the experiment for the morphological
characterization of certain ornamental cacti genera viz., Hylocereus triangularis, Myrtillocactus
geometrizans, Mammillaria beneckei, Hamatocactus setispinus, Ferocactus latispinus, Melocactus
caesius and Gymnocalycium mihanovichii, various morphological parameters viz., growth form,
characteristic features of ribs, areoles and spines, stem colour, plant height, plant girth, number of
areoles have been evaluated for their suitability to be used in tropical landscaping. The morphological
characterization of the above said cacti has revealed that Hylocereus triangularis and Myrtillocactus
geometrizans can be used as potential rootstocks whereas Mammillaria beneckei, Hamatocactus
setispinus, Ferocactus latispinus, and Gymnocalycium mihanovichii can be used as suitable scions in
grafting programme.