Osservazioni Microbiologiche Sui Nettaii di Piante Alpine

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     

Ciclo di Accrescimento E Differenziazione Delle Gemme in Piante Perenni Nel Territorio di Bari

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.     

L'evoluzione della cerchia legnosa in Arbutus Andrachnoides Link. in Firenze,dal luglio 1946 al Giugno 1947

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.     

Cenni Ecologici su Alcune Piante Notevoli (O Nuove) per la Flora Romana e Loro Attivitàg nella Costituzione della Vegetazione Laziale

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.     

Ricerche Morfologiche e Anatomiche Su Mimosa Pudica L.

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.     

Osservazioni Fenologiche Sulle Serpentine Dell'Impruneta (Firenze)

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.     

Naturalizzazione E Riproduzione Spontanea Di Piante Ornamentali Nella Liguria Occidentale

Abstract

Effects of the growth-retarding compounds «CCC» and «AMAB» on the growth and alkaloidal content of Datura Stramonium L. — Datura Stramonium L. was administered two fortnightly-doses of 200 cc 10 ^-2 M solutions of (2-cloroethyl)-trimethylammonium chloride (CCC) or (allyl)-trimethylammonium bromide (AMAB), poured on the soil of every pot. In the treated plants were noted shorter and thicher stems and petioles and leaves larger in size and darker green than in the controls. Yields of leaves in CCC and AMAB-treated plants were not significantly changed while root fresh and dry weights were decreased. The per-cent concentration of total alkaloids in the leaves and roots of both CCC and AMAB-treated plants was not significantly different in comparison with that of normal plants. Therefore the A. assumes that the growth-retarding chemicals must not interfere with alkaloidal synthesis.     

La Marana di Ciminiera (Foggia)

Summary

A «marana» of the Foggia Plain (Puglie) is a depression where water accumulates from the surrounding higher ground, and, very often, springs from the undersoil where the clay layer curves upwards. The soil is generally saline. It is not tillled but is grazed by herds of water-buffaloes. In the Marana di Ciminiera the auth. has found a mosaic of highly saline soils (with Salicornia fruticosa, Suaeda fruticosa, etc.), subsaline meadows (with Juncus acutus, Althaea officinalis, etc.), and fairly deep bogs, mostly drying up in summer (with Iris Pseudo-Acorus, Typha angustifolia, Phragmites communis, etc.).

A dense stand of Inula Helenium, one of Ligustrum vulgare, Lonicera etrusca, Crataegus Oxyacantha, Thalictrum flavum, Schoenus nigricans, and the general aspect of Lago della Contessa are described. Plants collected in the «marana» are listed.