Note 257 — Chapter I · PHYLLODY.

This distinction between laminar and vaginal venation is well seen in cases like Mussaenda, Calycophyllum, or Dipterocarpus, where the enlarged calycine segment has a strictly vaginal arrangement of its veins, very different from that which occurs in the true leaf-blades. These are cases, therefore, where the sheath of the leaf is unusually enlarged, and are not to be referred, as is often done, to metamorphosis of one or more sepals to perfect leaves. Prolified roses, cherries, &c., furnish frequently parallel cases. With reference to Mussaenda, C. Morren held the view that the petal-like sepal was really a bract adherent to the calyx, and incorporating with itself one of the calycine lobes—"soudée au calice et ayant dévorée, en englobant dans sa propre masse, un lobe calicinal." The Belgian savant considers this somewhat improbable explanation as supported by a case wherein there were five calyx lobes of uniform size, and a detached feather-veined leaf proceeding from the side of the ovary lower down ('Bull. Acad. Belg.,' xvii, p. 17, Fuchsia, p. 169).