A SHORT GLOSSARY OF BOTANICAL TERMS xxiii 



RACHILLA, a secondary axis in the inflorescence of grasses. 



RACHIS, the stalk of a compound leaf; the primary axis of certain kinds of 



inflorescence. 



RADICAL, springing from the root. 

 RADICLE, the embryo root. 



RAY FLORETS, the outer flowers of the Composites ; cf. Disk Florets. 

 RECEPTACLE, the top portion of the axis of a flower which bears the flora 



envelope and the male and female organs ; also the axis bearing the florets 



in Composites. 



RECURVED, bent back moderately. 

 REFLEXED, bent back considerably. 

 REGULAR, divided equally. 

 RENIFORM, kidney-shaped or bean-shaped. 

 RETICULATED, like a network. 

 RETRORSE, directed backward or downward. 

 RETUSE, very obtuse or truncate and slightly indented. 

 REVOLUTE, rolled back, as towards the underside of a leaf. 

 RHIZOME, a creeping, prostrate underground stem, bearing erect or sometimes 



prostrate shoots. 



RHOMBOIDAL, approaching a quadrangular, not square. 

 RINGENT, strongly 2-lipped and gaping. 



ROOT-STOCK, a thick short rhizome ; or the crown of the root. 

 ROSETTE, a somewhat circular group of leaves arranged in a close and spreading 



manner, often flat on the ground. 

 ROSTRATE, beaked. 



ROTATE, a monopetalous corolla with short tube and very spreading limb. 

 RUGOSE, wrinkled. 

 RUNCINATE, pinnatifid, with the lobes pointing backwards ; e.g. a Dandelion 



leaf. 

 RUNNER, a slender, prostrate, and generally rooting stem-branch. 



SAGITTATE, arrow-shaped, the auricles or lobes pointing backwards. 



SCABROUS, rough to the touch. 



SCALE, a thin, disk-like growth on the exposed surface of some leaves and stems. 



SCAPE, a naked flower stem springing direct from the root and bearing a single 

 flower. 



SCARIOUS, thin and more or less transparent and not green, but scaly and dry. 



SECUND, all turned towards one side. 



SEED, a fertilised ovule. 



SEPAL, one of the divisions of the calyx. 



SERRATE, edged like a saw. 



SERRULATE, with very small saw-like teeth. 



SESSILE, stemless. 



SETA, a bristle, or a slender straight prickle. 



SETACEOUS, like a bristle. 



SHEATH, the lower part of a leaf or its petiole, which forms a sort of tube sur- 

 rounding the stem. 



SHRUB, a woody perennial plant without a main trunk. 



SILICULE, a short seed-pod in Cruciferous plants, such as Draba ; adj. Siliculose. 



SILIQUA, a linear seed-pod in Cruciferous plants, such as Wallflower ; adj. 

 Siliquose. 



SINUOUS or SINUATE, wavy ; when teeth on the margin of a leaf are broad and 

 irregular lobes or notches. 



SPADIX, a fleshy spike, as in Arum maculatum. 



SPATHE, a sheath-like leaf enveloping a flower, as in Arum. 



SPATHULATE, broadened in the short upper half and narrowly contracted below. 



SPECIES, a unit of a genus of greater or less affinity. 



SPERMATOPHYTES, seed-plants. 



SPIKE, a simple inflorescence of sessile flowers attached to a simple axis. 



