“…In species with endospermous seeds, the hyperphyll is completely hidden in the seed, functioning as a haustorial organ. The cotyledonary hypophyll then mostly appears as the small cotyledonary sheath without any pronounced tubular elongation and without appendages, the cotyledon as a whole represents the compact type (TILLICH a, 1998(TILLICH , 2000see Fig. 1 A , B).…”
The paper gives a detailed morphological analysis of seedlings of 45 genera of Araceae. Including all seedling descriptions in the literature, informations for 60 genera are available now.
Generally, the cotyledon is subdivided into a bifacial hypophyll and a unifacial hyperphyll. The presumably most ancestral seedling type is characterised by a compact cotyledon, the cotyledonary hyperphyll is a haustorium inside the copious endosperm. Furthermore, it has a well growing primary root, the plumule gives rise to one to several cataphylls until the first eophylls develop. Starting from this type, two very different evolutionary lines can be followed. The first one leads to a seedling of which the cotyledonary hypophyll is transformed to an assimilating, blade‐like organ, while the minute unifacial hyperphyll is haustorial and hidden in the seed (e.g. Philodendron, Colocasia, Sauromatum ). The second line leads to endospermless seeds, the cotyledonary hyperphyll is transformed to a voluminous storage organ, hypocotyl and primary root are completely missing (e.g. Aglaonema, Arophyton, Nephthytis ). Many tribes are characterised by one or by two closely related seedling types, but a few tribes encompass a surprising diversity of seedlings (e. g. Caladieae, Spathicarpeae, Areae). The possible adaptive value of different seedlings is discussed.
“…In species with endospermous seeds, the hyperphyll is completely hidden in the seed, functioning as a haustorial organ. The cotyledonary hypophyll then mostly appears as the small cotyledonary sheath without any pronounced tubular elongation and without appendages, the cotyledon as a whole represents the compact type (TILLICH a, 1998(TILLICH , 2000see Fig. 1 A , B).…”
The paper gives a detailed morphological analysis of seedlings of 45 genera of Araceae. Including all seedling descriptions in the literature, informations for 60 genera are available now.
Generally, the cotyledon is subdivided into a bifacial hypophyll and a unifacial hyperphyll. The presumably most ancestral seedling type is characterised by a compact cotyledon, the cotyledonary hyperphyll is a haustorium inside the copious endosperm. Furthermore, it has a well growing primary root, the plumule gives rise to one to several cataphylls until the first eophylls develop. Starting from this type, two very different evolutionary lines can be followed. The first one leads to a seedling of which the cotyledonary hypophyll is transformed to an assimilating, blade‐like organ, while the minute unifacial hyperphyll is haustorial and hidden in the seed (e.g. Philodendron, Colocasia, Sauromatum ). The second line leads to endospermless seeds, the cotyledonary hyperphyll is transformed to a voluminous storage organ, hypocotyl and primary root are completely missing (e.g. Aglaonema, Arophyton, Nephthytis ). Many tribes are characterised by one or by two closely related seedling types, but a few tribes encompass a surprising diversity of seedlings (e. g. Caladieae, Spathicarpeae, Areae). The possible adaptive value of different seedlings is discussed.
“…No desenvolvimento foliar em eudicotiledôneas, a porção superior usualmente dá origem ao limbo e pecíolo foliar, enquanto a porção inferior à bainha e às estípulas (Kaplan 1973;Bell 2008). Por outro lado, nas monocotiledôneas, em geral, a maior parte da estrutura foliar tem origem a partir da porção inferior (Kaplan 1973;Tillich 1998;Buzgo & Rudall 2002). Nesse contexto, sugere-se que as diferenças no crescimento ou retenção entre as porções superior e inferior explicam a ampla variedade de formas entre os filomas das plantas (Kaplan 1973(Kaplan , 1975.…”
Section: As Diferenças Intraflorais Dos Estames Em Microlicia Euphorb...unclassified
“…O início do desenvolvimento da sépala de Leandra melastomoides é similar ao encontrado na literatura para algumas folhas, especialmente de monocotiledôneas (Kaplan 1973(Kaplan , 1975Tillich 1998). A similaridade baseia-se no surgimento de um primórdio perpendicular ao ápice meristemático, ereto desde seu início, com um único eixo de crescimento, seguido pelo estabelecimento de uma zona ventral de crescimento tal qual uma formação secundária sobre a superfície ventral (ver Franck 1976;Buzgo & Rudall 2002).…”
Section: Morfologia Do Cálice Em Leandra Melastomoidesunclassified
“…Autores no passado buscaram estabelecer a relação entre as partes de órgãos filomáticos, como o Vorläuferspitze da sépala de Passiflora e o pecíolo foliar (Puri 1947). Entretanto, tais inferências não parecem adequadas (Tillich 1998;Buzgo & Rudall 2002). Atualmente tem se admitido que as relações sejam mais bem estabelecidas entre origem ontogenética (p.ex.…”
Section: Morfologia Do Cálice Em Leandra Melastomoidesunclassified
“…limbo foliar nas eudicotiledôneas e bainha foliar nas monocotiledôneas). Nesse sentido, nossa abordagem é menos tipológica (Franck 1976;Buzgo & Rudall 2002) Tillich 1998). Apenas a análise ontogenética cuidadosa pode esclarecer a contribuição de cada porção/parte na formação do órgão maduro (Kaplan 1973, Bloedel & Hirsch 1979.…”
Section: Morfologia Do Cálice Em Leandra Melastomoidesunclassified
This review compares new developmental models on flowering and other vascular plants with evolutionary hypotheses formulated by Agnes Arber and like-minded botanists. Special emphasis is laid on philosophical basics such as perspectivism, pluralism about evolutionary modelling, continuum way of thinking, and fuzzy logic. Arber's perspective is best labelled as F uzzy A rberian M orphology (FAM Approach). Its proponents ('FAMmers') treat structural categories (e.g. 'roots', 'shoots', 'stems', 'leaves', 'stipules') in vascular plants as concepts with fuzzy borderlines allowing intermediates (including transitional forms, developmental mosaics). The FAM Approach complements Cla ssical Plant M orphology (ClaM Approach), which is the traditional approach in botany. ClaM proponents ('ClaMmers') postulate that the structural categories of vascular plants are regarded as concepts with clear-cut borderlines and without intermediates. However, during the evolution of vascular plants, the root-shoot distinction and the stem-leaf distinction have become blurred several times due to developmental changes, resulting in organs with unique combinations of features. This happened, for example, in the bladderworts (Utricularia, Lentibulariaceae). When focusing on the 'leaf', the FAM Approach is identical to Arber's 'partial-shoot theory of the leaf' and Sinha's 'leaf shoot continuum model'. A compound leaf can repeat the developmental pathway of the whole shoot, at least to some degree. For example, compound leaves of Chisocheton(Meliaceae) with indeterminate apical growth and three-dimensional branching may be seen as developmental mosaics sharing some growth processes with whole shoots! We focus here on the FAM Approach because this perspective is especially promising for developmental geneticists studying flowering and other vascular plants.
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