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| Publication Type | J |
| Authors | Rzedowski, J. |
| Title | Some plant associations of the soils of Lake Texcoco |
| Source | Bol Soc Bot Mexico |
| Abstract | Lake Texcoco is 1 of the 3 bodies of water remaining after the recession through drainage of the large lake of 700 km2 occupying the center of the Valley of Mexico at the Conquest. Often now reduced to 100 km2 during dry periods, it is convenient to employ the contour line for 2247 m above sea level as its boundry. Included are some salty, wet soils occupied by Distichlis stricta. Man as well as precipitation controls the variable depth which seldom exceeds 0.5 m. Its waters are saline and alkaline and vary in both these respects with season and with depth. Cations are mainly sodium, and anions, chlorides and bicarbonates. Soils when exposed are solonetz or black alkali clays. Factors impeding the growth of vegetation are salinity and alkalinity (pH 9-10) of the waters and soils; variability in depth of water; and overgrazing. Most of the vegetation is halophytic but there are also non-halophytic aquatics and weeds. The aquatics are found in canals, ditches, mouths of ravines, or around springs and small permanent bodies of fresh water. In the helostadion (terminology of Huguet de Villar) are found: Aganipea bellidiflora, Cyperus bourgaei, Eleocharis dombeyana, Hydrocotyle verticillata, Juncus balticus, Jussiaea repens, Leersia hexandra, Polygonum hydropiperoides, P. punctatum, Sagittaria macrophylla, Scirpus lacustris, S. pungens, Typha latifolia; in the ploadostadion: Nymphaea sp., Potamogeton pectinatus; in the baphostadion: Myriophyllum hippuroides; in the epileon: Azolla caroliniana, Eichornia crassipes, Lemna minor, L. gibba, L. valdiviana, Wolffia columbiana; and in the hypoleon: Ceratophyllum demersum. The terrestrial plants may be divided: (1) those of the salty, alluvial soils of the older flat shore and (2) those at the margins of canals and ditches. On the shore plains are found: Ambrosia peruviana, Arenaria bourgael, Atriplex linifolia, Bouteloua simplex, Cyperus esculentus, C. melanostachys, Euphrosyne parthenifolia, Leptochloa dubia, Lippia nodiflora, Lythrum alatum, Medicago denticulata, Muhlenbergia tenuiflora, Nierembergia angustifolia, Petunia parviflora, Ranunculus donianus, Sanvitalia procumbens, Silvia serphylllfolia, Sonchus asper, Trifolium amabile, Xanthocephalum centauroides, Distichlis spicata, Suaeda nigra, Juncus baltlcus, Chenopodium mexicanum, Trianthema portulacastrum, Seauvium portulacastrum, Atrlplex muricata, Heliotroplum curassavicum, Sporobolus argutus, Hordeum jubatum and Xanthocephalum humile, of which the last 11 are most common. Some of their ecological char-acteristics are tabulated. Along the canals and ditches occur: Agrostis semivertlcillata, Ambrosia peruviana, Aster exilis, Atriplex muricata, Baccharis glutinosa, Bacopa monnieri, Beta vulgaris, Bidens chrysanthemoides, Cyperus bourgael, C. esculentus, C. melanostachys, Distichlls splcata, Echinochloa crusgalli, E. crusgalli var. zelayensis, Eleocharis dombeyana, Erigeron bonariensis, E. scaposus, Juncus balticus, Medicago dentlculata, Nasturtium mexicanum, Panicum repens, Polygonum hydropiperoides, Polygonum punctatum, Polypogon elongatus, Polypogon monspeliensis, Ranunculus cymbalaria, R. dichotomus, Rumex mexicanus, Sagittaria macrophylla, Salix bonplandiana and Urtica dioica var. angustifolia. || ABSTRACT AUTHORS: A. J. Sharp |
| Publication Date | 1957 |
| Year Published | 1957 |
| Volume | 21 |
| Beginning Page | 19-33 |
| Unique Article Identifier | BCI:BCI19583200018619 |
| Plants associated with this reference |