APJSTOLOCHIE^— BIRTHWORT TRIBE 115 



flax Tlii'dum ; the Germans, Ldnblatt ; the Dutch, VlaschUad ; the liussians, 

 Litiossisti/ icai. M. de Caiulolle terms this species T. Imviifilsum. 



2. Erect Bastard Toad-flax (T. hilmile). — Stems erect, branched 

 from the base ; leaves linear, 1 -nerved, fleshy ; flowers in spiked racemes, 

 sessile, with three bracts ; fruit four or five times as long as the perianth : 

 perennial. Specimens of this plant have been gathered in Devonshire, but 

 it is not an indigenous plant. 



Order LXXIV. ARISTOLOCHIEiE — BIRTHWORT 



TRIBE. 



Perianth attached to the ovary below, tubular above, with a wide mouth ; 

 stamens G — 10 or 12, inserted on the ovary; ovary 4 — 6-celled ; styles 6, 

 their inner surface stigmatic ; fruit 4 — 6-celled, manj^-seeded. The order 

 consists of shrubs or herbaceous, often climbing plants, very abundant in the 

 warmer parts of South America, but rare in other countries : they contain 

 bitter, tonic, and stimulant propeities. 



1. BiRTHWORT (Aridoldrhia). — Perianth tubular, curved, SAvollen at the 

 base, the mouth dilated on one side ; anthers 6, inserted on the style ; stigma 

 6-lobed ; capsule 6-celled. Name, the old Greek, having reference to its 

 former use as an aid in parturition. 



2. AsARABACCA (Asdrtnn). — Perianth bell-shaped. 3-cleft ; stamens 12, 

 inserted at the base of the style ; style 6-lobed ; capsule 6-celled. Name 

 from the Greek a, not, and snm, a wreath, because it was excluded by the 

 ancients from their garlands. 



1. BiRTHWORT (Aristoldchia). 



Common Birth wort (J. clemafitis). — Stems erect, without branches; 

 leaves heart-shaped, stalked, smooth ; flowers upright ; lip oblong, tapering ; 

 root creeping, and perennial. This plant, though not truly wild, seems so 

 long since to have been established in some parts of the east and south of 

 England, that it may be regarded as naturalized. It grows among ruins, 

 and bears in May dull yellow flowers, growing several together. The corolla 

 is swollen at the base, but contracted above, and expanding with an oblong 

 lip with a short point. The swollen part of the flower is clothed, inside, 

 with stift" hairs, pointing downwards, and the authors of the "British Flora" 

 remark, " When the flower is expanded it is not uncommon for a little insect 

 [Tipula ijennicm'nis) to enter it, the stiff" hairs preventing its egress until it 

 has brushed off the pollen from the anthers upon the stigma ; the perianth 

 then becomes withered, the hairs become flaccid, and the insect makes its 

 escape." This statement needs some qualification. It is now known that 

 the stigmas are mature before the anthers shed their pollen, and should the 

 flies have previously visited a Birthwort flower, they Avill bring pollen on 

 their bodies and convey it to the stigmas of the flower they are now in. When 

 the stigmas have become no longer susceptible and have begun to wither, 

 the anthers shed their pollen and dust the flies with it. Then, and not till 

 then, do the hairs in the flower-tube shrivel and set the prisoners free, who 



15—3 



