ANGIOSPERM^, DICOTYLEDONES. 771 



rising from the bottom of the ovar'j'. The stamens, five in number, are inserted in 

 front of the petals, and are adnate to them (ejnpetalous). The fruit is a unilocular 

 capsule or drupe. The seeds contain an endosperm, in which the embryo is 

 embedded. 



The ovary is surmounted by a single style in Primulacese and Myrsinaceae, by 

 five styles in Plumbaginaceae. The capsules of Primulaceee are many-seeded, those 

 of Plumbaginaceae are one-seeded. In the genus Glaux only one floral envelope is 

 developed. It has the appearance of a perianth, and resembles that of Polygo- 

 naceae. It is interpreted as being a petaloid calj'x. The fact that in Glaux the 

 stamens occupy the same position in relation to the sepals as the petals do in other 

 cases warrants our supposing that what is usually designated as the corolla in 

 Primulaceae is only a whorl of stamens with connate petaloid filaments. The 

 Primulaceae are distributed mainly in the temperate zone of the Northern Hemi- 

 sphere. Most of the species of the genera Primula, Soldanella, and Androsace are 

 alpine plants. The Alps and the Himalayas are particularly rich in these species. 

 Androsace glacialis (see fig. 221 ^) occurs in the Alps in the neighbourhood of 

 glaciers at a height of 3160 metres above the sea-level. Primula pubescens, a plant 

 obtained by Clusius in 1582 from the Gschnitzthal in Tyrol, was the original species 

 from which Auriculas were derived during the fashion for their cultivation which 

 prevailed in the seventeenth century. The Plumbaginaceae are represented by 

 large numbers of species on the shores of the Mediterranean and in the saline 

 steppes of the East. The Myrsinaceae grow exclusively in the tropics. Fossil 

 remains of Myrsinaceas are known amongst the deposits of the Tertiary period. 

 The number of species now existing is about 1100. 



Alliance LII. — Tubiflorae. 



Families: Gentianacece, Asclepiadacece, Apocynacece, Loganiaceoe, Gonvolvulacece, 

 Polem,oniacece, Hydrophyllaceoi, Boraginacece, Nolanaceae, SolanacecB, 

 Scrophulariacece, LentibulariacecB, BignoniacecB, Acanthacece, Gesneracece, 

 Orobanchacece, Globulariacece, PlantaginacecB, Myoporaceoe, Verbenacece, 



Labiatce, Oleacece, Jasminacece. 



Annual or perennial herbs, shrubs, and trees. Flowers actinomorphic and 

 zygomorphic, hermaphrodite and pseudo-hermaphrodite. Floral-leaves in two 

 4-5-partite whorls; the lower whorl in the form of a calyx, the upper in the form 

 of a coi'olla. Petals united. Gynaeceum 2- or more celled, ovary superior. The 

 ovules are developed either on the turned-in margins of the carpels or on an axile 

 placenta. The andrcecium is composed of a whorl of 2-5 stamens. The fruit is 

 either a succulent berry, a capsule with various modes of dehiscence, or a drupe. 



The Solanaceas, Sei-ophulariaceae, Loganiaceae, and Asclepiadaceae contain poison- 

 ous alkaloids, the Gentianaceas contain bitter substances, and the Labiatae contain 

 etherial oils and ai-omatic substances. The majority of Tubiflorae possess green 

 foliage-leaves. Some Scrophulariacece, e.g. the species of the genus RehmM/nnia, are 



