BEACTS OE FLORAL LEAVES. 189 



IL Flowers in Cymes. 



1. Uniparous Cyme. 



a. Heliooid Cyme (axes forming a spiral). 



* Elongated form, Alstromeria. 



* * Contracted form, Witsenia corymbosa. 



5. Scorpioid Cyme (axes unilateral, two rows). 



* Elongated form, i^orjfei-me-Koi, Symphytwmj.Henliane. 



* * Contracted form, Erodium, Alchemilla wrvensis. 



2. Biparous Cyme (Dichotomous), including 3-5-cliotomous Cymes. 



a. Elongated form, Gerastiiim, Stella/ria. 



b. Contracted form (Verticillaster), Dead-nettle, Pelargonium. 



3. Compound Definite Inflorescence. 



Streptocarpus polyanthus, many Calceolarias. 

 C. Mixed Inflorescence. 



1. Raceme of Scorpioid Cymes, Morse-chestnut. 



2. Scorpioid Cyme of Capitula, Vernonia centriflora, 



3. Compound Umbel of Dichotomous Cymes, Lawrustinus. 



4. Capitulum of contracted Scorpioid Cymes (Glomerulus), Sea-pirik. 



2. — Bracts or Floral Leaves. 



Flowers arise from the axil of leaves, called Bractece, bracts or 

 floral leaves. The term bract is properly applied to the leaf, from 

 which the primary floral axis, whether simple or branched, arises, 

 while the leaves which arise on the axis between the bract and the 

 outer envelope of the flower are hracteoles or bractlets. Bracts some- 

 times do not difler from the ordinary leaves, and are then called 

 leafy, as in Veronica hederifolia, Vinca, Anagallis, and Ajuga. Like 

 leaves, they are entire or divided. In general, as regards their form 

 and appearance, they differ from ordinary leaves, the difference being 

 greater in the upper than in the lower branches of an inflorescence. 

 They are distinguished by their position at the base of the flower or 

 flower-stalk. Their phyllotaxis is similar to that of the leaf. When 

 the flower is sessile the bracts are often applied closely to the calyx, 

 and may thus be confounded with it, as in Malvacese and Eosacese, 

 where they have received the name of epicalyx (p. 198). In many 

 cases bracts seem to perform the function of protecting organs, within 

 or beneath which the young flowers are covered in their earliest stage 

 of growth. 



When bracts become coloured, as in Amherstia nobilis. Euphorbia 

 splendens. Erica elegans, and, Salvia splendens, they may be mistaken 

 for parts of the corolla. They are sometimes mere scales dJ- threads, 

 and at other times they are abortive, and remain undeveloped, giving 

 rise to the ebracteated inflorescence of Cruciferse and some Boraginacese. 

 Sometimes no flower-buds are produced in their axil, and then they 

 are empty. A series of empty coloured bracts terminates the inflores- 

 cence of Salvia Horminum. The smaller bracts or bracteoles, which 

 occur among the subdivisions of a branching inflorescence, often produce 

 no flower-buds,, and thus anomalies occur in the floral arrangements. 



