. The water-balance of succulent plants. Desert plants; Plant ecology; Cactus. FORM-ALTERATIONS AND GROWTH OF CACTI. Individual and Local PECtfLiARiTiES. Long--continued measurements have brougrht to light several minor facts which, while they do not affect the main question, are of sufficient impor- tance to record. As might be expected, each plant has a marked individ- uality, and it was possible before the measurements were made to predict with considerable accuracy what their deportment with regard to present conditions would be. One plant responded to rain more quickly than another, or in
. The water-balance of succulent plants. Desert plants; Plant ecology; Cactus. FORM-ALTERATIONS AND GROWTH OF CACTI. Individual and Local PECtfLiARiTiES. Long--continued measurements have brougrht to light several minor facts which, while they do not affect the main question, are of sufficient impor- tance to record. As might be expected, each plant has a marked individ- uality, and it was possible before the measurements were made to predict with considerable accuracy what their deportment with regard to present conditions would be. One plant responded to rain more quickly than another, or in a more marked degree, and some expanded for a longer period and were slower to contract when the weather became dry. The latter class usually included the more vigorous individuals, with larger trunks and wider furrows. There was no external indication of a cause for this condition of affairs, but it seems likely that in such cases the water was in some way held longer in the soil or pockets of rock to which their roots had access. As already noted elsewhere, not only the in- dividual plant, but parts of the same plant, re- spond differently to variations in amount of water in the soil, according to their location as to height and to points of the compass. But aside from this there are sometimes marked differences in the action of two intervals so close together that neither height nor ex- posure to the sun could account for the dif- ference. Perhaps the most marked case of this kind is that of intervals Nos. I and VI on sahuaro No. 4 (fig. 5). Both are on the southwest side of the stem, little more than 10° apart, and No. I is but 3 inches higher than No. VI, the latter being located just below the insertion of a rib where the furrow forks. As would be expected from their proximity and general similarity of position, both exhibit the same general response to changes of water- supply, the curves rising and falling together with much >regularity; but VI plainly shows more s
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectcactus, bookyear1910
