258 MANUAL OF BOTANY 



et P., which contam species. Their proiDerties and uses are 

 unknown. 



Order 44. Empetrace.e, the Cro wherry Order. — Cha- 

 racter. — Small heath-hke evergreen shrubs. Leaves exstipu- 

 late. Flowers axillary, small, unisexual. Calyx of 4 — 6 persist- 

 ent, imbricate, hypogynous scales, the innermost occasionally 

 petaloid and combined. Stamens alternate with, and equal in 

 number to, the inner sepals or scales. Ovary superior, placed 

 on a disc, 2^9-celled ; ovules solitary. Fruit fleshy, composed 

 of from 2 to 9 nuts. Seed solitary in each nut, ascending ; 

 embryo with an inferior radicle in fleshy-watery albumen. 



Distribution and Numbers. — Mostly natives of Northern 

 Europe and North America. Illustrative Genera : — Empetrum, 

 Linn. ; Corema, Don. There are 4 species. 



Pro2)erties and Uses. — The leaves and fruit are generally 

 slightly acid. The berries oiEinpetrum iiigrum, the Crowberry, 

 are eaten in the very cold parts of Europe, and are also em- 

 ployed in Greenland in the preparation of a fermented liquor. 

 In Portugal, the berries of Corema are used in the preparation 

 of a beverage which is said to be useful in febrile complaints. 



Order ^b. CeratophyllacetE, the Hornwort Order. — Cha- 

 racter. — Aquatic herbs. Leaves verticillate, very finely divided. 

 Floiuers minute, axillary, sessile, monoecious. Calyx or rather 

 perianth inferior, 8 — l2-partite. Male floiver consisting of 

 12 — 20 stamens ; anthers sessile, 2-celled. Female flower with 

 a superior 1-celled ovary, and 1 pendulous orthotropous ovule. 

 Fruit hard or nut-like, indehiscent. Seed exalbuminous, 

 pendulous ; embryo with a large many-leaved plumule, and a 

 very short inferior radicle. 



Distribution and Properties. — Natives of the northern hemi- 

 sphere. Ceratopjhyllum, Linn., is the only genus. The proper- 

 ties and uses of the species are unknown. 



Artificial Analysis of the Orders in the Sub-class. 

 ■ MoNOCHLAMYDE^ or Incomplet.i:. 

 {Modified from Lindley.) 



1. A c h 1 a 111 y d e o u s Flowers. 

 A. Leaves stipulate, 

 a. Flowers unisexual. 

 Ovary 1-celled. 



Ovules numerous . .... Salicaccce. 



