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| Zamia multidentata Segalla, Pimenta & Calonje. 2023. |
Abstract
Zamia multidentata is described and illustrated here as a new species from the Amazon basin, state of Acre, Brazil. The new species shares morphological similarities with the Amazonian species Z. hymenophyllidia, and Z. urep, to which it is compared. The combination of slender (to 6.2 cm) caulescent stems, strongly serrulate elliptic leaflets with long acuminate tips and a pronounced adaxially raised longitudinal crease, as well as seed strobili with long peduncles (15 cm +) and flat megasporophylls distinguish the new species Zamia multidentata from all other known species in the genus.
Keywords: Amazon basin, Amazon rainforest, Serra do Divisor, Sierra del Divisor, Gymnosperms
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| Reproductive characteristics of Zamia multidentata. A. Near mature ovulate strobilus, B. Mature ovulate strobilus with ripe seeds, C. Immature ovulate strobilus. D. Megasporophyll shield, E. Megasporophyll with two mature seeds with sarcotesta intact, F. Seed sclerotesta, G. Pollen strobilus at pollen dehiscence stage, H. Microsporophyll abaxial view, I. Microsporophyll adaxial view, J. Pollen strobilus cross section showing microsporophyll arrangement, abaxial side, K. Close up of distal half of pollen strobilus. All photographs used for the preparation of the illustration were taken at the type locality. |
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| Zamia multidentata in habitat. A. Adult plant in habitat with post-receptive ovulate strobilus, B. Abaxial side of leaf, with Márcio Sombra, C. Adult plant with Rosane Segalla for scale, D. Adult plant growing near river. The nutrient poor sandy soils of the region evident on the opposing riverbank. All photographs taken at type locality. |
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| Vegetative characteristics of Zamia multidentata. A. Median leaflet attached to rachis, B. Top view of eophyll, C. Habit of adult individual with ovulate strobilus. D. Newly emerging leaf showing slightly reflexed ptyxis and indumentum covering rachis, E. Middle section of petiole showing some patches of indumentum and prickles, F. Leaf. All photographs used for the preparation of the illustration were taken at the type locality. |
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| Comparison of microsporophylls and leaflets of Zamia multidentata, Z. hymenophyllidia, and Z. urep. A. Microsporophyll of Z. multidentata, abaxial side, B. Median leaflet of Z. multidentata, adaxial side, C. Microsporophyll of Z. hymenophyllidia, Nong Nooch Tropical Botanical Garden (NNTBG) accession 16022A, originally collected from Loreto, Perú. D. Median leaflet of Z. hymenophyllidia, adaxial side, photographed in Leticia, Amazonas, Colombia, E. Microsporophyll of Z. urep, abaxial side, F. Median leaflet of Z. urep, adaxial side. Photographs of Z. multidentata from material collected at type locality, photographs of Z. urep from NNTBG accession 15233A. |
Rosane Segalla, Ricardo Soares Pimenta and Michael Calonje. 2023. Zamia multidentata (Cycadales, Zamiaceae), A New arborescent Species of Zamia from Acre, Brazil. Phytotaxa. 598(1); 21-31. DOI: 10.11646/phytotaxa.598.1.2