@article {165,
	title = {Metabolic adaptation and vertical zonation of Littorella uniflora (L.) Aschers. and Isoetes lacustris L.},
	journal = {Aquatic Botany},
	volume = {4},
	year = {1978},
	note = {Cited By (since 1996):10Export Date: 11 November 2013Source: Scopus},
	month = {1978///},
	pages = {1 - 10},
	abstract = {The seasonal variation of photosynthesis and respiration was investigated in the two dominating plant species of contrasting vertical zonation in the oligotrophic Lake Kalgaard, Denmark, namely Littorella uniflora (L.) Aschers. (0-2 m) and Isoetes lacustris L. (2.0-4.5 m). The photosynthesis at a given temperature in low or high irradiance, and the chlorophyll content of Littorella and Isoetes were almost independent of season. In accordance with the zonation, the light-saturated net photosynthesis of Littorella was consistently higher compared with Isoetes and the difference increased with temperature (5-20{\textdegree}C). The photosynthesis in low irradiance, on the other hand, was often slightly, but not significantly, higher in Isoetes and, despite its higher chlorophyll content and lower specific leaf area, the slope of the initial part of the photosynthesis-light curve was rather similar for the two species. The dark respiration of the underground parts was lower than the leaf respiration and, in addition, the respiration was lower for Isoetes than for Littorella. The physiological responses are discussed in relation to the ecological conditions in oligotrophic lakes and to the distributional pattern of the two species. {\textcopyright} 1978.},
	url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-0002036139\&partnerID=40\&md5=10106045a111768457d8024b24b026a9},
	author = {Sand-Jensen, K.}
}
@article {166,
	title = {Structure and development of sieve elements in the root of Isoetes muricata dur.},
	journal = {Annals of Botany},
	volume = {42},
	year = {1978},
	note = {Export Date: 11 November 2013Source: Scopus},
	month = {1978///},
	pages = {15 - 21},
	abstract = {Root tissues of Isoetes muricata Dur. were fixed in glutaraldehyde and postfixed in osmium tetroxide for electron microscopy. Very young root sieve elements can be distinguished from contiguous parenchyma cells by the presence of crystalline and/or fibrillar proteinaceous material in dilated cisternae of rough endoplasmic reticulum (ER). Similar crystalline-fibrillar material accumulates in the perinuclear space. During differentiation, the portions of ER enclosing this proteinaceous substance become smooth surfaced and migrate to the cell wall. Along the way many of them form multivesicular bodies which fuse with the plasmalemma, discharging their contents toward the wall. Nuclear degeneration is pycnotic. At maturity, the sieve element contains a degenerate, filiform nucleus, plastids, and mitochondria. In addition, the wall of the mature sieve element is lined by a plasmalemma and a parietal network of smooth ER. Sieve-area pores are present in both end and lateral walls of mature sieve elements. Whereas a single cluster of pores occurs in each end wall, the pores of the lateral walls are solitary and few in number. {\textcopyright} 1978 Annals of Botany Company.},
	url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-49349132852\&partnerID=40\&md5=67d8953cc7808df8f64f219b72d811b2},
	author = {Kruatrachue, M. and Evert, R.F.}
}
