38 Santalaceae, Loranthaceae 



Fam. Santalaceae. Chlorophyllous hemi-para- 

 sites. Leaves mostly alternate, entire, exstipulate. Tepals 

 4-5, valvate in bud, bracteoid or petaloid, united below. 

 Stamens adnate to tepals. Ovary i-locular with a 

 columnar, free central placenta from which are sus- 

 pended the 1-3 ovules which are without integument. 

 Fruit indehiscent, with one endospermous seed. 



Tribe Thesieae. Perianth epigynous. Tube long. 



Only British genus : Thesium. 



Suborder 2. LORANTHINEAE. Ovules mostly not 

 differentiated. 



Fam. Loranthaceae. Evergreen shrubs, mostly 

 parasitic on trees. Leaves thick, usually opposite and 

 exstipulate. Tepals usually 4, valvate, fleshy. Floral 

 axis united to gynaecium^ often forming a crenate ring 

 {calyculus). Ovary i-loc, usually with only one fertile 

 embryo sac. Fruit a pseudo-berry, inner layer of axis 

 becoming sticky. 



Subfamily Viscoideae. Flowers diclinous. No 

 distinct calyculus. 



Tribe Visceae. Flowers single or in groups in the 

 axils of persistent bracts. Placenta basal. 



Only British genus : Viscum. 



Order 7. Aristolochiales. Flowers cyclic, homo- 

 chlamydeous, epigynous, actinomorphic or zygomorphic. 

 Perianth petaloid. Ovary inferior, usually 3-6-locular. 

 Ovules always 00 , mostly axile. 



Fam. Aristolochiaceae. Herbs or lianes, with 

 alternate, long-stalked, usually cordate or reniform, ex- 

 stipulate leaves. Flowers usually hermaphrodite, actino- 

 morphic or zygomorphic. Perianth petaloid, with three 



