29. PRIMULACE^. 



105 



style 1, with 2 long branches: ovary inferior; fruit dry, 

 hard, enclosed in the involucre. 



Male flowers with an involucre of free 

 bracts ; receptacle scaly ; female flowers 

 2 together ; fruit rather large, 2-seeded XANTHirM 1 



Male flowers with a 1-leaved involucre; re- 

 ceptacle naked; anthers pointed; female 

 flowers solitary in the involucre, clus- 

 tered within bracts; fruit small, 1-seeded Ambrosia 



1. Xanthium, L. 



1. Xanthium spinosuin, 



L. Bathurst Burr. Stout annual, 

 branching from base, downy 

 with appressed • hairs ; leaves 

 .stalked, soft, dark - green above, 

 with white nerves, white - tonien- 

 tose below, wedgeshaped at base, 

 entire or 3-o-lobed, the terminal 

 lobe long, lanceolate ; one or two 

 3-branched spines at the base of 

 each leaf; male heads in the 

 upper axils ; female heads of 2 

 combined flowers in a closed, 

 spiny involucre; fruit downy, 

 covered with yellow, hooked 

 spines, terminating in 2 unequal 

 beaks. 



A troublesome weed on road- 

 sides, pa.stures, and waste places. 

 Feb. -July. — Probably of South 

 American origin ; now naturalised 

 in most warm countries. 



Ainbrusla arteniisifoJia, L., a villous North American 

 weed, naturalised in Europe, has appeared near Mount 

 Barker. Lower leaves bipinnatisect ; flowers in long 

 cylindrical .spikes (the male flowers above), forming a 

 panicle ; fruit obovoid, beaked, with 4-6 small tubercles or 

 spines near the summit. 



Family 29.- PRIMULACEvE. 



1. Anagallis, L. 



1. Anagrallis arvensis, L. Pimpernel. Procum- 

 bent glabrous annual, with weak quadrangular stem and 

 branches; leaves opposite or in whorls of 3, sessile, oval, 

 3-o-nerved ; flowers red or blue, solitary in each 

 axil, on slender peduncles longer than the leaves and 

 finally recurved: calyx of o lanceolate segments; corolla 

 wheeLshaped, with a very short tube and o oval 

 segments, crenat« and glandular at the summit ; filaments 



Xanthium spinosum. 



