SKCT. II 



PHANEROGAMIA 



677 



The individual flowers are either radially symmetrical with a five-lobed corolla 

 (Fig. 727, b, c) or they are two-lipped as in the South American Mutisieae, the 

 upper lip having two teeth, the lower three. By suppression of the upper lip 

 flowers with a single lip are derived ; such flowers exhibit three teeth at the tip (Fig. 





Fig. 728. —Longitudinal section of capituhini— «, of Lappa major with floral bracts ; 6, of Matricaria 

 Chamomilla without floral bracts. (After Berg and Schmidt, magnified.) 



727 a). The ligulate flowers (e.g. of Taraxacum, Fig. 734) are similar in general 

 appearance to the latter ; the corolla is here deeply split on one side and its 

 margin bears five teeth. In addition to those Compositae which have only 

 ligulate or only tubular florets in the head, there are many which have tubular 

 florets (disc-florets) in the centre, surrounded by one-lipped florets (ray-florets) 

 (Fig. 728 b). These usually differ from one another in sex as well as in colour; 

 the disc -florets are hermaphrodite, 

 the ray-florets j^urely female . The 

 flower-heads are thus heterogamous 

 {Matricaria, Arnica). Lastly, the 

 marginal florets may be completely 

 sterile {Centaurca C'yamis) and serve 

 only to render the capitulum con- 

 spicuous to insects. 



iMPOPa'ANT SUB-FAMILIES AND GEN- 

 ERA. 1. TubuUflorae, the heads con- 

 tain only tubular florets ; («) Cynareae. 

 The enlarged axis of the inflorescence 

 or common receptacle has setaceous 

 floral bracts ; the involucral leaves 

 form several series and are prickly 

 or have membranous margins. The 

 flowers are either all hermaphrodite 

 or the marginal florets are sterile. 

 Style swollen below the stigmas into a cushion-like ring. Fruits with a pappus. 

 C'arduus (Plumeless Thistle), pappus of simple, hair-like bristles. Cirsiuvi, with 

 feathery pappus. Echinops, with single-flowered capitula associated in numbers. 

 Lappa (Burdock), involucral bracts with recurved, hook-like tips (Fig. 728 a). 

 Cyaara Sco/ymus (Artichoke). Caicus beneclictus (Fig. 733), capitula solitary, 

 terminal, surrounded by foliage leaves. Involucral bracts with a large, sometimes 



2X2 



Fio. 729. — Arnira montana. a, Receptacle of capi- 

 tulum after removal of fruit ; 6, fruit in longi- 

 tudinal section, the pappus only partly shown. 

 (After Berg and Schmidt, magnified.) 



