Sympodial structure of spikelets in the tribe Schoeneae (Cyperaceae).
نویسندگان
چکیده
Spikelet morphology of 250 specimens of 47 species of Schoeneae was examined using light microscopy and scanning electron microscopy. We confirmed that spikelet structure in Schoeneae is cymose with a sympodial "rachilla." Monopodial spikelets, as described by most current literature, were not found in Schoeneae. Prophylls are not always present in sympodial spikelets and cannot be used to determine whether a spikelet is sympodial or monopodial. Spikelets of Schoeneae develop acropetally, and the uppermost glume may or may not produce a flower. The last feature may be variable within species and within individual plants, so presence or absence of this flower is not an indication of sympodial or monopodial spikelet structure in Schoeneae. Relative position of flower, glume, and axis is a reliable criterion to judge whether spikelets are sympodial or monopodial. In some species of Schoenus and in Ptilothrix, formation of the arch-shaped base of the fertile glume relates to the shape of the inclined nodes on which the glume grows. This study highlights the need to reinvestigate spikelet structure in other tribes of Cyperaceae.
منابع مشابه
Sedges in the mist: A new species of Lepidosperma (Cyperaceae, Schoeneae) from the mountains of Tasmania
The status of a putative new species of Lepidosperma from the mountains of south-western Tasmania, Australia, was investigated. Phenetic analysis (Flexible UPGMA Agglomerative Hierarchical Fusion and semi-strong hybrid multidimensional scaling) was conducted on a database derived from morphological and anatomical characters scored from herbarium material, culm anatomy slides and scanning electr...
متن کاملFlower and spikelet morphology in sawgrass, Cladium jamaicense Crantz (Cyperaceae).
In recent systematic treatments of the Cyperaceae, spikelets of all but the most primitive tribes have been considered to be indeterminate, whereas historically the number of flowers, floral sex and distribution of sexes in spikelets have been important characters in suprageneric classifications. However, descriptions of these spikelet characteristics for sawgrass, Cladium jamaicense Crantz, va...
متن کاملThe Schoenus Spikelet: a Rhipidium? A Floral Ontogenetic Answer
The inflorescence unit of Schoenus nigricans and S. ferrugineus consists of a zigzag axis and distichously arranged bracts, each of which may or may not subtend a bisexual flower. Each flower seems to terminate a lateral axis. These features have led to a controversy about the nature of the inflorescence unit, particularly whether it is monopodial or sympodial. It was often seen as a pseudospik...
متن کاملGlume absence in the Orcuttieae (Gramineae: Chloridoideae) and a hypothisis of intratribal relationships
This study addresses glume absence in tribe Orcuttieae. In Orcuttia califomica, 0. inaequalis, and 0. viscida, all spikelets possess two glumes except for the terminal spikelet of the inflorescence, which lacks both glumes. In 0. pilosa and Tuctoria greenei the terminal spikelet lacks only the first (proximal) glume, whereas in 0. tenuis, T. fragilis, and T. mucronata both glumes are developed ...
متن کاملPhylogeny of Abildgaardieae (Cyperaceae) Inferred from ITS and trnL–F Data
Within the tribe Abildgaardieae, the relationships between Fimbristylis and its relatives have not been certain, and the limits of Fimbristylis have been unclear, with Bulbostylis and Abildgaardia variously combined with it and each other. The relationships and limits of tribes Abildgaardieae and Arthrostylideae and their genera were evaluated across 49 representative species using parsimony an...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- American journal of botany
دوره 91 1 شماره
صفحات -
تاریخ انتشار 2004