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21.
Dott. Benedetta Mancuso 《Plant biosystems》2013,147(1-2):335-344
Summary The Author studies the secondary wood in a Cherry tree «Regina del Mercato» and describes several degenerative factures in the wood elements. The author concludes that there is a close relation between number and development of the leaves and differentiation of secondary wood elements. 相似文献
22.
Dott. Maria Arena 《Plant biosystems》2013,147(3-4):395-422
Summary The vegetative growth of the olive tree in Messina is described. The growth period begins at the end of March and prosecutes without interruption as late as November. The secondary wood tissue producted during summer time (from Yuly to August) is abnormal being of a parenchimatoide type. During winter there is a well defined rest period. The cambium produces secondary wood and bark with an alternate rythm, so that in spring the wood production prevails on the liber and in autumn the opposite condition is realized. Each phase of production of secondary conducting tissues (wood as well as bark) is followed by a phase of starch storing. In the stem several false wood rings are produced during one year, while in the young branches each wood ring corresponds to one year. The longitudinal growth and cork formation on the branches of the year are particularly pronounced during spring (March-May). Cambium cells swell in a characteristic way before they start dividing and collapse during the resting periods, thickening evidently their walls, so that in winter it is difficult to distinguish a cambial cell from a parenchimatic one. The behaviour of the vegetative growth of the olive tree in Messina is discussed on the base of the climatic characters of the region. 相似文献
23.
Dott. Maria Viesti 《Plant biosystems》2013,147(4):487-495
Summary The author has studied the flora of a few country lanes in the surroundings of Molfetta (Apulia). The various stations are described and the plants collected are listed. 相似文献
24.
25.
Dott. Alessandro Marcello 《Plant biosystems》2013,147(2):269-280
Riassunto Lo sviluppo del gametofito femminile di Campsis radicans (L.) Seem. (Bi-gnonaceae) è di tipo normale, monomegasporiale, otto-nucleato. Le cellule somatiche dell'ovulo durante lo sviluppo del gametofito e la loro trasformazione in tessuto nutritizio presentano particolari fenomeni interessanti non solo dal punto di vista morfologico, ma anche da quello microchimico. L'ispessimento attivo della membrana delle cellule dell'ipostasi è preceduto dall'acquisto di un intenso potere cromotropo e di un aspetto mucillaginoso : il passaggio delle sostanze pectiche della membrana cellulare da uno stato di inerzia ad uno di accrescimento coinciderebbe secondo ogni verosimiglianza con l'acquisto di radicali solforici da parte dei loro polisaccaridi. L'amido del gametofito adulto in via di degenerazione acquista un intenso potere cromatropo determinato dai prodotti della sua demolizione 相似文献
26.
Dott. Vittoria Armenise 《Plant biosystems》2013,147(3):391-417
Summary Growth cycle and buds differentiation in perennial plants growing in Bari's area. — V. The evolution of the wood ring in Rhammus Alaternus L. from December 1946 to March 1949. In Rhamnus Alaternus L. the cambium awackens in March with the production of an early wood, characterized by large vessels and loose fibers. It keeps on dividing the following months, producing intermediary wood, whose vessels become narrower and narrower. In June the wood ring is almost complete and the cambial activity slows down. In July late wood is formed, with narrow tracheae and highly lignified fibers. From August to February cambial activity is very scarce and irregular, in the wood produced fibers being tangentially compressed. In a young branch of R. A. cambium becomes suddenly active in February, that is one month before than in the stem, it goes on during the month of March-June, with an evident diminution in the size of the wood elements. This diminution of size instead of being regular, shows some oscillations, expecially during the month of May. In Sept. the cambium starts again dividing, but rather poorly and irregularly, forming some vessels a little wider than the preceeding ones, so that an incomplete false ring is formed only in some points of the branch. As a rule the autumn wood is a typical late wood. This scarce and irregular cambial activity goes on also during Oct.-Dec. In January is more active and forms rather wide vessels in comparison with those formed in the preceeding month. This new formed wood however does not show the characteristics of the early wood of a new ring. Concluding, the characteristics of the cambial activity of A. R. are In the stem: 1) March: early wood. 2) March-June: intermediary wood. 3) July: late wood, resting period. 4) At the end of Autumn a scarce production of late wood is sometimes possible. In the young branch: 1) February: early wood. 2) March-June: intermediary wood, with positive and negative oscillations in the vessels width. 3) At the end of June the late wood is already differentiated. 4) July-August: resting period. 5) Spt.-Juan.: the cambium starts again dividing very scarcely and producing a transition wood between the two rings. This wood can be regarded neither as a true ring nor a false one, it represents rather the last phase of the late wood formation. 6) In the young branch of the female specimen the cambium starts dividing somewhat later than in the male one. 7) The wood ring width does not vary much in relation to the yearly amount of rainfall. The lack of relation between rainfall and ring width is particularly evident in 1948 (a rainy year). The, «Compleasance» of R. A. could show that this species is, in Puglia, in its own habitat. On the other hand it is rather peculiar that R. A. forms only one wood ring during one year, with production of early wood during the spring, and of late wood in the autumn, instead of producing a second autumn ring following a distint summer rest, as could be expected. 相似文献
27.
Dott.Ssa Ornella Vergnano 《Plant biosystems》2013,147(4):639-645
Summary The evolution of the wood ring in arbutus andrachnoides link, in florence (from July 1946 to June 1947). The anatomical characters of the wood ring of the stem and of the young branch of Arbutus andrachnoides Link have been studied in Florence. The results are the following: the cambial tissue in the stem starts dividing at the end of April and continues during the summer months, ending completely in September. In the branch the cambium differentiates almost a month earlier, namely at the beginning of April. In both cases the only wood ring produced is completed at the end of September. Comparing the evolution of this wood with the climatic factors it can be seen that the cambium activity starts in a period of remarkable rainfall and of regular increase of temperature and presents a remarkable activity still at the end of August. Arbutus andrachnoides Link. is a spontaneous hybrid between A. Unedo and A. Andrachne and its distribution (in Greece and in the gréek islands) shows that A. Unedo and A. Andrachne had the possibility to overlap in this area and to produce this hybrid. 相似文献
28.
Dott. Giuliano Montelucci 《Plant biosystems》2013,147(3):366-418
Summary The A. notes some new localities of Latium in which he has found several plants interesting for their rarity, but chiefly for their phytogeographical features in reference to the stations in which these species were found. The following plants are for Latium as new: Bifora radians M. B., Cuscuta pentagona Eng., Lippia nodiflora Rich., Galinsoga parviflora Cav., Lapsana hirta Ten. 相似文献
29.
Dott. Ester Maugini 《Plant biosystems》2013,147(3-4):505-519
Summary Firstly, the author describes the anatomical and histological structures of Mimosa pudica L. during the stages of development of the young plant prior to the appearing of cambium. She then discusses, in the light of previous literature on the subject, the three principal features of Mimosa pudica: herbaceous bearing, stable tetrarchy with intercotyledonal bundles along the plumule, and small sized germination. Finally, the author concludes that Mimosa pudica appears to be an individual with tree-like rather than herbaceous symmetry (stable tetrarchy), in which the size of germination has diminished parallelly to reduction in size of the adult individual. 相似文献
30.
Dott. Ida Bargoni 《Plant biosystems》2013,147(3-4):232-251
Riassunto L'A. deserive la vegetazione di due stazioni delle serpentine dell'Impruneta e riporta le osservazioni condotte negli anni 1938–40 sul ritmo di vegetazione delle specie che popolano tali stazioni. Dalle osservazioai fenologiche risulta che il risveglio della vegetazione sulle serpentine non è ritardato alla primavera per le specie pi[ugrave] tipiche, mentre lo è per talune specie banali; che le parti secche delle piante tendono a rimanere lungamente in posto; che la disseminazione è lenta e si protrae spesso fino all'autunno inoltrato od anche fino alla primavera successiva. 相似文献