xxvrr. rosacea. 
117 
follow the prevailing custom of uniting the two, although the divi- 
sion be a natural as well as convenient one to the student. 
Ord. XXVII. ROSACE2E Juss. 
Calyx 4 — 5-lobed, free, or adherent with the ovary. Petals 5, 
perigynous, equal. Stamens perigynous, definite or indefinite, 
with an incurved aestivation ; anthers 2-celled, bursting longi- 
tudinally. Carpels many, rarely solitary, and then situated be- 
tween two of the lobes of the calyx (when these are 5), 1 -celled, 
1 — 2 or more seeded, free, or combined with each other and with 
the calyx. Styles simple, often lateral, distinct or combined. 
Seeds ascending or suspended, nearly without albumen : embryo 
straight, with fleshy or foliaceous cotyledons. — Herbs, or Shrubs, 
I or Trees. Leaves alternate , with stipules one on each side the base 
of the petiole. — The pulpy fleshy fruits are esculent ; while the 
plants which produce them are often poisonous from the pre- 
sence of Prussic acid, with which many of the species abound. 
Laurel-water is extracted, not from a true Laurel, but from an 
individual of this Natural Order, Prunus Lauro- Cerasus : the 
Bitter- Almond owes its flavour to that acid. Some produce a 
gum ; others are astringent. Roots of Tormentil yield a dye ; 
, others are febrifuges. The qualities residing in the species of 
this Order entitle it to a high rank among British Vegetables. 
I Sub-Ord. I. AiiYGnAl.E.K Cat-pel solitary, superior. Style 1. Calyx- 
tube deciduous. Stipules free. 
1. Prunus. 
Sub-Ord. II. Rose.e. Carpels not adhering to the calyx- tube. Stipules 
# united to the petiole. 
Tribe 1. Spik.eid.e. Petals several. Fruit a ring of follicles not in- 
closed within the calyx tube. 
2. Sfirjsa. 
Tribe 2. PoTENTir.T.m.E. Calyx-tube short and nearly flat, not enclosing 
the fruit. Petals several. Achenes or drupes 5 or more upon a 
common flat or convex receptacle. 
* Achenes tipped with a long awn (the permanent style'). 
3. Dryas. Awns feathery, not jointed. Receptacle flat. 
4. Geuji. Awns jointed. Receptacle elongated. 
** Achenes or drupes with a short style. 
1 5. Rubus. Drupes. Calyx simple (without external bracteoles). 
6. Fragaria. Achenes on a large fleshy deciduous receptacle. Calyx 
double (i. e . with as many external bracteoles at its summit "as 
divisions, and alternate with them). 
7. Comarum. Achenes on a spongy permanent receptacle. Calyx 
double. Petals smaller than the calyx. 
