For example, diffuse axial parenchyma is often claimed to be associated with heterocellular rays, presence of tracheids as the imperforate tracheary type, and vessels with scalariform
guianensis which are horizontal (scalariform
, gash-like) to vertical (palisade).
Each cell has eight to 10 layers of scalariform
thickenings, this character gives the seed a deep honeycomb appearance.
4): The shell is small for the subgenus, being slightly more than 4mm long, and 0.41 times as wide as long, with scalariform
, strongly shouldered whorls.
A few multiperforate perforations (modified scalariform
, with variously shaped perforations) present.
Sieve plates are scalariform
, showing radial and tangetial distribution in sieve elements and a high staining reaction for cellulose and hemicellulose.
Hypothesis: Because air emboli tend to stop at perforation plates, regardless of whether perforation plates are scalariform
or simple (Slatyer, 1967), shorter vessel length may be disabled in a plant with shorter vessel elements.
What is the syndrome of features associated with the scalariform
pitting pattern of tracheary elements?
1930): "In view of the proof offered that the transition from the protoxylem to the secondary xylem represents a primitive to specialized sequence which is palingenetic, and the accurate portrayal this sequence gives the change from scalariform
to porous perforations, there is little reason to doubt that the detailed transitions here illustrated give a connected picture of the evolution of the scalarifiorm vessel segment from the scalariform
tracheid" (1930, pp.
or araucaroid, uniseriate to triseriate, bordered pitting.
On the other hand, Carpenter and Dickison (1976) admitted that whereas both Oncothecaceae and Theaceae are characterized by relatively unspecialized wood anatomy (e.g., solitary vessels with small diameter, very oblique endwalls, and scalariform
perforation plates in Oncotheca), the presence of multilacunar nodes in Oncotheca is in sharp contrast to the unilacunar nodes so characteristic of Theaceae.
Chenery and Sporne (1976) hypothesized that aluminum hyperaccumulation is a primitive character based on a statistical correlation with seven primitive characters: woodiness, scalariform
perforation plates, scalariform
vessel pitting, apotracheal parenchyma, nonstoried wood, early fossil records, and tropical rain-forest distribution.