|
|
||||||||
2Institut für Systematische Botanik der Universität Zürich, Zollikerstrasse 107, CH-8008 Zürich, Switzerland; and 3Institut für Pharmazie der Johannes Gutenberg-Universität Mainz, Saarstrasse 21, D-55099 Mainz, Germany
Mourera fluviatilis from northern South America is a spectacular member of the Podostemaceae (river-weeds). Its raceme-like inflorescences are up to 64 cm long and have 4090 flowers arranged in two opposite rows. Inflorescence development starts with the initiation of a double-sheathed (dithecous) bract in a terminal position. All lateral bracts (again dithecous) are initiated in basipetal order along the two flanks of the inflorescence. Each gap between two neighboring bracts contains a single flower. The flowers are bisexual, each with a whorl of 1620 ligulate tepals and 1440 stamens, which are arranged in one or two whorls. Floral development starts with the formation of a girdling primordium rim around a two-lobed primordial gynoecium. Stamen and tepal initiation is centrifugal on the girdling primordium. The anthers are introrse or extrorse, depending on stamen position. Seedlings develop two entire, threadlike cotyledons, followed by forked filamentous leaves, which arise from the plumular pole. The radicular pole of the hypocotyl develops into a claw-shaped holdfast that fixes the young plant to the rock. The developmental morphologies of Mourera fluviatilis and other members of the Mourera group (including Lonchostephus and Tulasneantha) fit well with the Podostemoideae bauplan known from other New World genera, such as Apinagia and Marathrum.
Key Words: basipetal bract inception inflorescence morphogenesis Mourera fluviatilis Podostemaceae polystemonous flowers seedling morphology terminal leaf water plants
This article has been cited by other articles:
![]() |
S. Koi and M. Kato Developmental Morphology of the Shoot in Weddellina squamulosa and Implications for Shoot Evolution in the Podostemaceae Ann. Bot., June 1, 2007; 99(6): 1121 - 1130. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. Koi, R. Fujinami, N. Kubo, I. Tsukamoto, R. Inagawa, R. Imaichi, and M. Kato Comparative anatomy of root meristem and root cap in some species of Podostemaceae and the evolution of root dorsiventrality Am. J. Botany, May 1, 2006; 93(5): 682 - 692. [Abstract] [Full Text] [PDF] |
||||
![]() |
R. IMAICHI, Y. HIYAMA, and M. KATO Leaf Development in the Absence of a Shoot Apical Meristem in Zeylanidium subulatum (Podostemaceae) Ann. Bot., July 1, 2005; 96(1): 51 - 58. [Abstract] [Full Text] [PDF] |
||||
![]() |
K. SUZUKI, Y. KITA, and M. KATO Comparative Developmental Anatomy of Seedlings in Nine Species of Podostemaceae (Subfamily Podostemoideae) Ann. Bot., June 1, 2002; 89(6): 755 - 765. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. Ota, R. Imaichi, and M. Kato Developmental morphology of the thalloid Hydrobryum japonicum (Podostemaceae) Am. J. Botany, March 1, 2001; 88(3): 382 - 390. [Abstract] [Full Text] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |