.

_Radicant_, rooting, taking root on or above the ground.

_Radicels_, little roots or rootlets.

_Radicle_, the stem part of the embryo, the lower end of which forms the
root, 11, 127.

_Rameal_, belonging to a branch. _Ramose_, full of branches (_rami_).

_Ramentaceous_, beset with thin chaffy scales (_Ramenta_), as the stalks
of many Ferns.

_Ramification_, branching, 27.

_Ramulose_, full of branchlets (_ramuli_).

_Raphe_, see _rhaphe_.

_Ray_, parts diverging from a centre, the marginal flowers of a head (as
of Coreopsis, 94), or cluster, as of Hydrangea (78), when different from
the rest, especially when ligulate and diverging (like rays or
sunbeams); also the branches of an umbel, 74.

_Ray-flowers_, 94.

_Receptacle_, the axis or support of a flower, 81, 112; also the common
axis or support of a head of flowers, 73.

_Reclined_, turned or curved downwards; nearly recumbent.

_Rectinerved_, with straight nerves or veins.

_Recurved_, curved outwards or backwards.

_Reduplicate_ (in aestivation), valvate with the margins turned outwards,
97.

_Reflexed_, bent outwards or backwards.

_Refracted_, bent suddenly, so as to appear broken at the bend.

_Regular_, all the parts similar in shape, 82.

_Reniform_, kidney-shaped, 53.

_Repand_, wavy-margined, 55.

_Repent_, creeping, i. e. prostrate and rooting underneath.

_Replum_, the frame of some pods (as of Prickly Poppy and Cress),
persistent after the valves fall away.

_Reptant_, same as repent.

_Resupinate_, inverted, or appearing as if upside down, or reversed.

_Reticulated_, the veins forming network, 50. _Retiform_, in network.

_Retinerved_, reticulate-veined.

_Retroflexed_, bent backwards; same as _reflexed_.

_Retuse_, blunted; the apex not only obtuse but somewhat indented, 54.

_Revolute_, rolled backwards, as the margins of many leaves, 72.

_Rhachis_ (the backbone), the axis of a spike or other body, 73.

_Rhaphe_, the continuation of the seed-stalk along the side of an
anatropous ovule or seed, 112, 126.

_Rhaphides_, crystals, especially needle-shaped ones, in the tissues of
plants, 137.

_Rhizanthous_, flowering from the root.

_Rhizoma_, _Rhizome_, a rootstock, 42-44.

_Rhombic_, in the shape of a rhomb. _Rhomboidal_, approaching that
shape.

_Rib_, the principal piece, or one of the principal pieces of the
framework of a leaf, or any similar elevated line along a body, 49, 50.

_Rimose_, having