Odontonema strictum Kuntze, a commonly cultivated
shrub in Brazil, has red flowers grouped in inflorescences
and can reach two meters high. The objective of this work
was to study the root formation and morpho-anatomy
of herbaceous cuttings of Odontonema strictum. The
cuttings were planted in conical polyethylene container
with vermiculite of fine granulometry and coconut coat
powder. The experiment was conducted in a greenhouse
at the Federal University of Paraná, Curitiba, Brazil. The
cuttings were 12 cm long with two leaves cut by half in
the apical portion. The experimental design used was a
completely randomized with 4 replications of 10 cuttings
each one. After 44 days, the root formation was 100% on
the two studied growing media. The vermiculite presented
the higher number of roots per cutting (22,49 roots) while
the coconut coat powder presented the higher average of
root size per cutting (11,67 cm). Anatomically, the cuttings
of O. strictum presented unisseriate epidermis, with thick
walls; cortex composed by collenchyma, parenchyma,
and endodermis with casparian strips; central cylinder in
secondary state of growth, having pericycle with isolated
groups of fibers, active cambium and medular parenchyma.
The probable origin of adventitious roots is the peripheral phloem cells. The results indicate that the anatomical
characteristics of the cuttings do not block the formation
of adventitious roots, having no mechanical tissue on the
cortex. This species has easy root formation and there is
no need of plant growth regulator application.