18 GLOSSARY OF BOTANICAL TERMS. 



Oblong, much longer than broad, and rounded at both ends. 



Obovate, ovate with the broadest part above the middle. 



Obtuse, blunt. 



Opposite, two leaves or other organs rising from the same level on opposite sides 

 of the stem. 



Orbicular, flat, circular or almost so. 



Order, a group of families resembling each other. 



Orthotropous {atropous) , when an ovule has a straight axis, the chalaza being at 

 its base and the micropyle at the opposite end. 



Ovary, the lower part of the carpel or pistil, containing the ovules, and finally 

 becoming the fruit (fig. 2). Compound ovary, see syncarpous. 



Ovate, when a flat surface, such as that of a leaf, is egg-shaped and broader 

 below the middle. 



Ovoid, egg-shaped (of solid organs such as fruits). 



Ovule, the seed in its early stage. It consists of the embryo-sac, containing the 

 future embryo, completely surrounded by the nucellus, which is in its turn 

 surrounded (except at the micropyle) by an outer covering, usually consist- 

 ing of two coats, an inner and an outer. At the base of the ovule is a spot 

 called the chalaza, where nourishment enters from the placenta through the 

 funicle, and at the opposite extremity is the small opening through the outer 

 covering, which is called the micropyle (fig. 2). 



Palea, the upper of two bracts enclosing the flower of grasses. 



Palmatifid, leaf divided into diverging lobes, and so resembling the open hand. 



Palmatisect, palmately divided nearly to the base. 



Panicle, an inflorescence where the axis is divided into branches bearing several 

 flowers. 



Paniculate (panicled), arranged in a panicle. 



Papilionatc, pea-shaped (flower). 



Papillose, covered with minute protuberances called papillae. 



Pappus, a ring of hairs or scales which represents the calyx in many Compositae. 



Parasite, a plant growing upon another, and deriving its nourishment from the 

 latter. 



Parietal placenta, when the placentas and ovules are attached to the walls of a 

 1 -celled compound ovary. 



Parted {partite), an organ divided into parts almost to its base. 



Pedicel, stalklet of a flower, when the peduncle bears 2 or more pedicellate 

 flowers. 



Pedicellate, growing on a pedicel. 



Peduncle, stalk of a solitary flower, or common stalk (floral axis or rhachis) of 

 several pedicellate or sessile flowers. 



Pedunculate, growing on a peduncle. 



Peltate, leaf whose stalk is attached to its under-surface, instead of to the edge. 



Pendulous ovule, one hanging from the summit of the ovary. The term suspended 

 is sometimes used when the ovule is attached slightly below the summit. 



Penicillate, arranged like a tuft of hairs. 



Perennial, living for several years. 



Perianth, the floral envelope, usually consisting of 2 whorls, the calyx and 

 corolla. The term is specially employed to describe flowers in which the seg- 

 ments of the perianth are much alike but in whorls (as in Liliaceae and 

 Juncaceae) , or quite similar and in a single whorl (as in Chenopodiaceae) . 



Pericarp, the walls of the fruit, consisting of the ripened ovary. The walls or 

 layers may be more or less fused into one, or they may be easily distinguish- 

 able as three: the epicarp, mesocarp, and endocarp. In inferior fruits the 

 concave receptacle remains adherent to the pericarp and forms part of the 

 fruit. Combined epicarp and mesocarp are often called exocarp. 



Perigynous, when the sepals, petals, and stamens are inserted round the superior 

 ovary on the cuplike or tubular receptacle. The stamens also appear 

 perigynous when inserted on the corolla. 



Persistent, lasting until the fruit is ripe, as sepals or glumes; also applied to 

 leaves remaining green during the winter: the opposite of caducous and 

 deciduous. 



Petal, one of the divisions or leaves of the corolla, usually colored. 



Petaloid, resembling a petal. 



Petiolate, supported on a petiole. 



Petiole, stalk of a leaf. 



Tctxolule, stalk of a leaflet. 



