PHANEROGAM I A 587 



hairs. The bent position of the flower bud is characteristic of many Papaver- 

 aceae. Ultimately the flower becomes erect as it opens ; the two sepals forming 

 the calyx are thrown on", and the four, large, wrinkled petals, forming the 

 corolla, expand. Papaver somnifcrum, which is of oriental origin, has abundant, 

 white latex. The plant has a glaucous bloom and, except on the flower-stalks, 

 which bear a few bristly hairs, is glabrous. Leaves sessile, margin irregularly 

 serrate or lobed. Petals violet or white with a dark patch at the base. Ovary 

 unilocular, incompletely septate by the projection inwards of the numerous 

 placentas. Fruit ripens erect on the peduncle. In Papaver the separation of the 

 central portion of eaeh carpel from the placentas at dehisceuce is limited to the 

 tips of the carpels. These bend outwards just below the flat stigmatic expansion, 

 and the kidney-shaped seeds are thrown out of the small openings when the capsule 

 borne on its long stalk is moved by the wind. 



OFFICIAL. Papaver somnifcrum, the Opium Poppy, yields PAPAVERIS CAPSULAE 

 and OPIUM. Papaver llhoeas yields KHOEADOS PETALA. 



Family 2. Fumariaceae. Glabrous herbs, without milky juice, with bipinnate 

 or tripinnate leaves. Flowers bimerous throughout ; the number of whorls in the 

 corolla is doubled. Floral formula, K2, C2 + 2, A2, G(2). The outer petals, or one 

 of them, bear spurs. In the latter case the flower is transversely zygomorphic 

 (Figs. 608, 609). The inner whorl of stamens is suppressed. The stamens of the 

 outer whorl are each tripartite, consisting of a central anther with two thee and 

 twu lateral anthers each with a single theca borne on a common filament. In 

 Hir/H'i-niim. the lateral branches join in pairs, and apparently form the inner 

 staminal whorl, the position of which they occupy. The transversely zygomorphic 

 flowers of the Fumariaceae with only one spur afford the only example of this type 

 of symmetry. The fruits of Fumaria are nutlets, those of Corydalis and Dicentra 

 an- capsules. Dicentra spcctabilis, which is frequently cultivated, has a bisym- 

 metrical corolla with two spurs. Seeds with endosperm. 



Family 3. Cruciferae (- 3 ). Annual, biennial, or perennial herbs 

 without milky juice. Inflorescence racemose, usually without bracts 

 or bracteoles. Flowers actinomorphic, always lateral, composed of 

 bimerous whorls. Floral formula, K 2 + 2, C 2 + 2, A 2 + 4, G (2). 

 The outer whorl of sepals stands in the median plane ; the four- 

 petals alternate with the sepals. The two outer stamens are shorter 

 than the four inner ones which stand in the median plane. The 

 latter correspond to two stamens branched to the base. The carpels 

 form a superior, usiially pod-like, ovary, which is divided into two 

 chambers by a false septum stretching between the parietal placentas. 

 The fruit opens by the separation from below upwards of the main 

 portion of each carpel, leaving the seeds attached by their stalks to 

 the central portion formed by the placentas together with the false 

 septum. Rarely the fruit is indehiscent. Embryo curved. Endo- 

 sperm wanting or reduced to a single layer of cells coherent with the 

 seed coat (Figs. 610-616). 



The form of the fruit and the position of the embryo in the seed are used in 

 the subdivision of this extremely uniform family. This general classification, which 

 dates from the time of Linnaeus, will be used here, but reference must be made to 

 the more recent, natural division of the family, founded on characters afforded by 



