Silica and Ash in Several Marsh Plants

Ash and silica content and their depositional patterns in tissues of Spartina alterniflora Loisel., Distichlis spicata (L.) Greene, Scirpus validus Vahl., Zizania aquatica L., and Limonium carolinianum (Walt.) Britt. were determined. Zizania aquatica leaves had the highest silica content (6.0%) of any of the plant parts tested; silica making up over half of the ash. Silica in the plants was opaline in character. Limonium carolinianum did not accumulate silica in any great amount. However, ash content was very high in Limonium carolinianum and Scirpus validus making up over 17% of the dry weight of the leaves. X-ray diffraction showed the presence of halite (NaCl) and calcium sodium phosphate (2.4 CaO • 0.6 Na2O • P2Os) in the ash of the leaves of all the plants from Mississippi except Zizania aquatica. Mineral deposition (silica and other minerals) in Zizania aquatica occurs in rows lengthwise of the leaf, and there are bowtie- and oval-shaped phytoliths. In Distichlis spicata leaves, mineral deposits occur in rows of elongate, serrated units. Spongy mineral deposition occurs lengthwise of the leaves of Spartina alterniflora and some of these deposits, including the silica, are fibrous. In Scirpus validus heavy deposits occur lengthwise of the leaf. Silica occurs in a sheetlike pattern and in rows of oval particles

Silica and Ash in the Salt Marsh Rush, Juncus roemerianus

Silica content of living rhizomes from the perennial salt marsh rush Juncus roemerianushad values of 0.34, 0.20, and 0.60% of dry weight in three morphologically distinct populations along the Mississippi coast and was directly related to available silica content of the soil (29.7, 17.0, 169.6 mg/100g soil, respectively). On the other hand, living leaves had about the same average silica content (0.93, 0.87, 0.9070 or dry weight). The silica content of living leaves varied from 0.142% in younger leaves to 1.520% in older ones. Similarly, rhizomes also increased in silica content with age, varying from 0.137% in younger portions to 1.030% for older ones. Mature leaves collected in October all had a higher average silica content (0.737%) than those collected in April (0.413%), indicating that silica content also increases over the growing season. Decomposed leaves (dead-standing) had a relatively high silica content o f 1.8170, obviously reflecting a loss of organic matter and soluble minerals. Roots contain considerable silica, but reliable results were not possible as the soil could not be completely removed from them. Petrographic microscope studies showed that the silica was clear, colorless and isotropic with a refractive index of 1.43, all properties typical of the mineral opal. No α-quartz was present, as occurs in some species of Juncus. The silica was deposited in a sheet made up of small, irregular phytoliths arranged in rows lengthwise in the leaves. Ash percentages were much higher than those for silica and no definite conclusions could be drawn from their variation. In comparison to the maximum silica content of leaves from Juncus interior (3.21%), the concentrations found in leaves of J. roemerianus were relatively low

Silica and Ash in the Salt Marsh Rush, Juncus roemerianus

Silica content of living rhizomes from the perennial salt marsh rush Juncus roemerianushad values of 0.34, 0.20, and 0.60% of dry weight in three morphologically distinct populations along the Mississippi coast and was directly related to available silica content of the soil (29.7, 17.0, 169.6 mg/100g soil, respectively). On the other hand, living leaves had about the same average silica content (0.93, 0.87, 0.9070 or dry weight). The silica content of living leaves varied from 0.142% in younger leaves to 1.520% in older ones. Similarly, rhizomes also increased in silica content with age, varying from 0.137% in younger portions to 1.030% for older ones. Mature leaves collected in October all had a higher average silica content (0.737%) than those collected in April (0.413%), indicating that silica content also increases over the growing season. Decomposed leaves (dead-standing) had a relatively high silica content o f 1.8170, obviously reflecting a loss of organic matter and soluble minerals. Roots contain considerable silica, but reliable results were not possible as the soil could not be completely removed from them. Petrographic microscope studies showed that the silica was clear, colorless and isotropic with a refractive index of 1.43, all properties typical of the mineral opal. No α-quartz was present, as occurs in some species of Juncus. The silica was deposited in a sheet made up of small, irregular phytoliths arranged in rows lengthwise in the leaves. Ash percentages were much higher than those for silica and no definite conclusions could be drawn from their variation. In comparison to the maximum silica content of leaves from Juncus interior (3.21%), the concentrations found in leaves of J. roemerianus were relatively low

Silica and Ash in Several Marsh Plants

Ash and silica content and their depositional patterns in tissues of Spartina alterniflora Loisel., Distichlis spicata (L.) Greene, Scirpus validus Vahl., Zizania aquatica L., and Limonium carolinianum (Walt.) Britt. were determined. Zizania aquatica leaves had the highest silica content (6.0%) of any of the plant parts tested; silica making up over half of the ash. Silica in the plants was opaline in character. Limonium carolinianum did not accumulate silica in any great amount. However, ash content was very high in Limonium carolinianum and Scirpus validus making up over 17% of the dry weight of the leaves. X-ray diffraction showed the presence of halite (NaCl) and calcium sodium phosphate (2.4 CaO • 0.6 Na2O • P2Os) in the ash of the leaves of all the plants from Mississippi except Zizania aquatica. Mineral deposition (silica and other minerals) in Zizania aquatica occurs in rows lengthwise of the leaf, and there are bowtie- and oval-shaped phytoliths. In Distichlis spicata leaves, mineral deposits occur in rows of elongate, serrated units. Spongy mineral deposition occurs lengthwise of the leaves of Spartina alterniflora and some of these deposits, including the silica, are fibrous. In Scirpus validus heavy deposits occur lengthwise of the leaf. Silica occurs in a sheetlike pattern and in rows of oval particles