_Pyramidal_, shaped like a pyramid. _Pyrene_, _Pyrena_, a seed-like nutlet or stone of a small drupe. _Pyriform_, pear-shaped. _Pyxidate_, furnished with a lid. _Pyxis_, _Pyxidium_, a pod opening round horizontally by a lid, 124. _Quadri-_, in words of Latin origin, four; as _Quadrangular_, four-angled; _Quadrifoliate_, four-leaved; _Quadrifid_, four-cleft. _Quaternate_ in fours. _Quinate_, in fives. _Quinque_, five. _Quincuncial_, in a quincunx; when the parts in æstivation are five, two of them outside, two inside, and one half out and half in. _Quintuple_, five-fold. _Race_, a marked variety which may be perpetuated from seed, 176. _Raceme_, a flower-cluster, with one-flowered pedicels arranged along the sides of a general peduncle, 73. _Racemose_, bearing racemes, or raceme-like. _Rachis_, see _rhachis_. _Radial_, belonging to the ray. _Radiate_, or _Radiant_, furnished with ray-flowers, 94. _Radiate-veined_, 52. _Radical_, belonging to the root, or apparently coming from the root. _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 æstivation), 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.