PLANTS OF THE INDIAN DESEET. 289 



are found in Polygalaceae, some Elatlneae, Tiliaceae, Bosaceae and 

 Filicinae. 



(b) Ordinary simple uniseriate trichomes with walls smooth 

 muriculate or papillose occur in Burseraceae, Bhamncae, some Papili- 

 onaceae, Onagraceae, Gucurbltaceae, some Bublaceae, some Convol- 

 vidaceae, some Solanaceae, some Scrophular laceae , some Acanthaceae, 

 some Verbenaceae, Labiatae, some Amarantaceae, Chenopodiaccae and 

 some Euphorbiaceae. 



Special forms of uniseriate trichomes belong to the following 

 types: — 



(i) Trichomes with walls smooth or verrucose and with a long 

 terminal cell in some Compositae, Asclepladaceae and some 

 Amarantaceae. 

 (ii) Trichomes with terminal cell bent like a hook in Menisper- 

 maceae, some Papillonaceae, Arlstolochlaceae and Commeli- 

 naceae, 

 (iii) Two-armed trichomes with equal or unequal arms and 

 with walls smooth or muriculate in some Papillonaceae, 

 some Compositae, some Oonvolvulaceae and some Acantha- 

 ceae. 

 (iv) Adpressed trichomes in some Papillonaceae. 



(c) and (d) Peltate and stellate hairs are found in some Capparl- 

 daceae and some Ficoideae respectively. 



(e) Tufted hairs occur in some Malvaceae, Stercullaceae, some 

 Tiliaceae and some Solanaceae. 



if) and (g) Candelabra and shaggy hairs are of rare occurrence 

 and are found in some Amarantaceae and some Gapparldaceae respec- 

 tively. 



All the species except the fleshy ones are characterised by a 

 dense covering of clothing hairs of various shapes and structure as 

 described above. It should further be noted that clothing hairs aie 

 generally more numerous on the lower surface of the leaves and that 

 they are numerous over and about the veins, some times occurring in 

 groups over and about the mid-rib, though less abundant on other 

 portions of the leaf surface. All these facts may be understood as 

 proofs of localised extra nourishment, especially as they occur in 

 greater abundance about the veins. This is further proved by the 

 fact that fleshy plants belonging to Zygophyllum and Euphorbiaceae 

 are either glabrous or with a scantily developed covering of clothing 

 hairs. 



