FAMILIES OF FLOWERING PLANTS 143 
tate or palmately lobed or divided; the flowers, mostly large and showy, 
are quite irregular in structure, the calyx being prolonged into a nectar- 
bearing spur. The 5 petals are borne usually on long claws; stamens 
5; ovary usually 3-celled, capsular in fruit (see Fig. 125, no. 1). It is 
Tropaeolum majus which is such a universal favorite in our gardens, 
and which commonly bears the name “Nasturtium.” This is an inex- 
cusable misnomer, for Nasturtium was known for years as the genus- 
name of the water-cress; and the fact that the latter is now known by 
another scientific name (orippa) does not excuse the misappellation 
of Nasturtium. The word Tropaeolum is easy to pronounce and to 
remember. 
Family Linaceae. Flax 
_Family. Includes 4 genera and 
about 150 species of wide geo- 
graphic distribution in both 
temperate and tropical regions. 
The family is remarkable for 
the regularity and symmetry of 
its flowers, which have 4 or 5 
sepals, 4 or 5 alternating petals, 
4 or 5 stamens, and a 2-5-celled 
ovary (see Fig. 125 no. 2). 
The genus Linum is a large 
one, containing numerous North 
American, south European and 
African species. While several 
are in garden cultivation, the 
only one of importance is the 
common flax (L. usitatissimum). 
Fig. 125. Cross-sections of flowers; 1, Tropaeo- 
- i 3 « lum pentaphyllum. 2. Flax (Linum usitatissimum); 
This has been in cultivation ga and 3b. Redwood (Erythroxylon pulchrum) show- 
ing two forms of stamens and pistils. All natural 
since the earliest times, and is * 
size. Redrawn from Engler. 
one of those plants that is not 
now known to occur in the wild state. Besides the use of the fiber from 
its stems in the manufacture of fine linen, the seeds, when soaked in 
water, yield a mucilaginous substance possessing medicinal properties, 
and when pulverized an oil known as linseed oil is expressed from them, 
the resulting oil-cakes being éxtensively used for fattening cattle. 
Family Humiriaceae. Humiria Family. A group of South Amer- 
ican trees comprised in 3 genera and about 20 species. Humiria bal- 
samifera yields a reddish balsamic juice, which when dry is burned as 
an incense. A medicinal ointment is also prepared from it. The struc- 
ture of the flowers in this family is similar to that of the Linaceae, but 
the fruit is a drupe instead of a capsule. 
