GROUPS AND ORDERS. 135 



II II Ovary many-celled. 



(a) Stamens distinct, 



12. Elatinaceous plants — minute aquatic herbs ; the symmetrical 



flowers with three to five sepals and petals, and as many or 

 twice as many stamens. 



(b) Stamens monadelfhous. 



13. Linaceous plants — herbs ; leaves entire ; flowers symme- 



trical, witli five sepals and petals, and as many stamens 

 united at the base into one parcel ; carpels separating with- 

 out leaving a central axis. 



14. Geraniaceous plants — herbs; leaves divided; flowers sym- 



metrical, with five sepals and petals, and five or ten stamens 

 united into one parcel ; carpels fixed around a persistent 

 central axis. 



(c) Stamens polyadelphous. 



15. Hypericaceous plants — shrubs ; leaves opposite, often 



dotted ; flowers regular, with five sepals and petals ; stamens 

 indefinite, united below into 3-5 parcels. 



§§ Sepals parallel at the edge (\. e. valvate). 



16. Malvaceous plants — herbs or shrubs ; flowers regular, of 



five sepals and petals, surrounded by an involucre of three 

 or more bracts ; stamens numerous, their filaments united 

 into a tube around the pistil. 



17. Tiliaceous plants — trees; flowers attached to a leaf-like 



bract ; sepals and petals five ; stamens numerous, shortly 

 cohering in several clusters. 



XX Floioers irregular. 



18. Balsaminaceous plants — herbs ; flowers of six pieces, very 



irregular, the sepals and petals all coloured, one of the sepals 

 spurred ; stamens five, the anthers cohering round the pistil. 



