Identifier: textbookofstruct00thom (find matches)
Title: Text-book of structural and physiological botany
Year: 1877 (1870s)
Authors: Thomé, Otto Wilhelm, 1840- Bennett, Alfred William, 1833-1902
Subjects: Plant physiology
Publisher: New York : J. Wiley & sons
Contributing Library: Smithsonian Libraries
Digitizing Sponsor: Biodiversity Heritage Library

View Book Page: Book Viewer
About This Book: Catalog Entry
View All Images: All Images From Book
Click here to view book online to see this illustration in context in a browseable online version of this book.

Text Appearing Before Image:
Fig. 478.—Longitudinal section through the medullary sheath of the spruce-fir ; a-espiral vessels or vascular cells ; f-i transitional forms into the ordinary wood-fibres; k normal wood-fibre ; m cells of the pith (x 400). those of the root often in several rows, as well as that of theresin-passages, which are especially abundant in Coniferae,form an excellent diagnosis to distinguish the different kindsof wood (Fig. 479). The structure of the swollen stem of special Morpliology and Classification, 373 the Cycadeae is similar, the large pith containing a quantityof starch (known as sago), and surrounded by a com-
Text Appearing After Image:
Fig. 479.—Transverse section through the wood of the Scotch fir with moderatelylarge annual ring ; x x boundary of the annual ring ; s silver-grain (x 200). paratively slightly developed wood. Gum-passages replacein them the resin-passages of the Coniferae. 374 Strnctitral ajid Physiological Botany. (Dicotyledons are subdivided as under, viz. :— Division I. Apetal^, iNCOMPLEXyE, or Monochlamyde/e.Periaiith consisti7tg of ofily a single whorl of leaves^ or entirelyabsejzt, or occasionally of a double whorl ofsepaloid leaves, SUBDIVISION I. Ovary superior; perianth usually distinct. Cohort I. Chenopodiales. Flowers usually hermaphrodite; peri-anth green or coloured, usually regular, sometimes in two whorls, tubeshort or absent, segments imbricate in bud ; ovary of one, rarely severalcarpels ; ovules solitary, rarely two or more, basal ; embryo usuallycoiled or curved. Herbs or shrubs. This cohort includes the ordersPkytolaccacece (Phytolacca) ; Polygonacea; (Eriogomtm^ Polygonum^ Fa

Note About Images