Page:The Journal of Indian Botany.djvu/797

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 Papilionaceae, Onagraceae, Gucurbltaceae, some Bublaceae, some Convolvidaceae, 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 Capparidaceae 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.