Morphological characterization of Archontophoenix cunninghamii (Arecaceae) diaspores and seedlings | Caracterização morfológica do diásporo e da plântula de Archontophoenix cunninghamii (Arecaceae)

English. The palm Archontophoenix cunninghamii H.Wendl. & Drude, even  widely used in landscaping, has not been studied. In general, there are few articles on morphology of seeds and seedlings of Arecaceae species. With the aim of filling this gap, the objective of the present work describes the diaspore (seed with adhering endocarp) and the seedling morphology. A. cunninghamii seeds present rounded shape and a ruminated endosperm of hard consistency. The embryo is lateral, peripheral and relatively undifferentiated, approximately 4 mm long, conical, with one of the extremities convex, and in its inside there is a small protuberance while the other extremity is rounded and narrower. The seedling is adjacent ligulated and hypogeal, with the development starting from a mass of undifferentiated cells in the micropillar depression, the differentiation of shoot and root primordium, being the first enveloped by a sheath closed. The root system is fasciculate, with different adventitious roots and several lateral roots with few absorbent hairs. The stem comprises three sheaths surrounding the first young leaf, which are opened in succession, permitting the emergence of the primary bifid leaf, with typical parallel nerves.

Portuguese. A palmeira Archontophoenix cunninghamii H.Wendl. & Drude, embora muito utilizada no paisagismo ainda é pouco estudada. De maneira geral, os trabalhos sobre morfologia de sementes e plântulas de espécies de Arecaceae são escassos, desta forma, este trabalho teve como objetivo descrever a morfologia do diásporo e da plântula desta espécie. As sementes de A. cunninghamii têm forma arredondada e endosperma ruminado e consistência dura. O embrião é periférico e relativamente indiferenciado; com aproximadamente 4 mm de comprimento, de forma cônica, com uma das extremidades côncava no interior da qual se encontra uma pequena protuberância e a outra extremidade é arredondada e mais afilada. A germinação é adjacente ligulada e hipógea, sendo que o desenvolvimento se inicia a partir de uma massa de células indiferenciadas na depressão micropilar, a diferenciação dos primórdios caulinares e radiculares, sendo o primeiro envolto por uma bainha fechada. O sistema radicular é fasciculado, com raízes adventícias diferenciadas e várias raízes laterais, com poucos pelos absorventes. O primórdio caulinar é constituído por três bainhas que envolvem a primeira folha jovem, as quais se abrem, sucessivamente, permitindo a emergência da folha primária bífida, com nervuras paralelas típicas. Morphological characterization of Archontophoenix cunninghamii (Arecaceae)diaspores and seedlingsThe palm Archontophoenix cunninghamii H.Wendl. & Drude, even widely used in landscaping,has been poorly studied. In general, there are few articles on morphology of seeds and seedlingsof Arecaceae species. With the aim of filling this gap, the objective of the present work describesthe diaspore (seed with adhering endocarp) and the seedling morphology. A. cunninghamii seedspresent rounded shape and a ruminated endosperm of hard consistency. The embryo is lateral,peripheral and relatively undifferentiated, approximately 4 mm long, conical, with one of theextremities convex, and in its inside there is a small protuberance while the other extremity is roundedand narrower. The seedling is adjacent ligulated and hypogeal, with the development startingfrom a mass of undifferentiated cells in the micropillar depression, the differentiation of shoot androot primordium, being the first enveloped by a sheath closed. The root system is fasciculate, withdifferent adventitious roots and several lateral roots with few absorbent hairs. The stem comprisesthree sheaths surrounding the first young leaf, which are opened in succession, permitting theemergence of the primary bifid leaf, with typical parallel nerves.