622 POLEMONIACEZ.—DIAPENSIACEZ,—STILBACEA. 
Cohort 2. Polemoniales.—Corolla regular or nearly so. Stamens 
epipetalous, equal in number to, and alternate with, the 
lobes of the corolla, Leaves alternate or rarely opposite, 
usually simple and entire, or sometimes lobed, and rarely 
compound ; always exstipulate. 
Order 1. PotEMONIACES, the Phlox Order.—Character.— 
Herbs. Leaves opposite or alternate, simple or compound, 
exstipulate. Culyx inferior, 5-partite, persistent, generally 
regular. Corolla 5-lobed, with contorted or occasionally im- 
bricate zestivation. Stamens 5, alternate with the segments of 
the corolla ; pollen usually of a blue colour. Ovary 3-celled ; 
style 1; stigma trifid. Fruit capsular, 3-celled, 3-valved ; pla- 
centas axile. Seeds few or many ; embryo straight, in the axis of 
copious horny albumen ; cotyledons elliptical, foliaceous. 
Distribution and Nuwmbers.—They abound most in the tem- 
perate parts of North and South America; but are far less 
abundant in Europe and Asia, and altogether unknown in 
tropical countries. Illustrative Genera:—Phlox Linn; Pole- 
monium, Tourn ; Cobzea, Cav. There are above 100 species. 
Properties and Uses.—Of no importance except for the pretti- 
ness of their flowers. The seeds of Collomia and some other 
plants of this order have their testa covered with hair-like cells 
containing spiral fibres ; these fibres in Collomia expand in coils 
when the seeds are moistened. (See pages 45 and 335.) 
Orders 2 and 3. DIAPENSIACE# and SritpacE#.—These are 
two small orders of shrubby plants which are placed by Lindley 
in his Gentianal alliance, and regarded by him as nearly allied 
to Loganiacee. The Diapensiaceze are sometimes regarded, 
however, as being near to the Ericacez ; while others refer 
them to Convolvulacee. They have clearly affinities with both 
Polemoniaceze and Hydrophyllaceve, and hence are placed here. 
There are but 2 genera, and 2 species, the uses of which are 
unknown. They are natives of North America and Northern 
Europe.—The Stilbacez, of which there are 3 genera, and 7 
species, without any known uses, are natives of the Cape of 
Good Hope. 
Order 4. HypDROPHYLLACES, the Hydrophylilum Order.— 
Character.—Herbs, bushes, or small trees. Leaves usually 
hairy, lobed, and alternate. Flowers either solitary, stalked, 
and axillary; or numerous and arranged in a_scorpioidal 
manner. Calyx persistent, 5-partite. Corolla regular, 5-cleft. 
Stamens equal in number to, and alternate with, the segments of 
the corolla. Ovary 1—2-celled, with two parietal placentas ; 
styles and stigmas 2; ovules2 or many. Frwit capsular, 2-valved, 
2- or 1-celled. Seeds netted; albwmen hard, abundant. 
Distribution and Numbers. —Chiefly natives of the northern 
and most southern parts of the American continent. Illustrative 
