180 KEY TO SUB-CLASSES, ORDERS AND GENERA. 
C--LORANTHACEAi--cont. 
(I) Flowers bisexual, showy ; petals 4—6, linear, qe more or less con- 
nate ; leaves alternate, or opposite, or both:—  .. ... deexcix—Loranthus. 
(11) Flowers unisexual, inconspicuous ; offen leafless, or leaves opposite :— 
decc—Viscum, 
CI—SANTALACE A.— 
[Botanical note.—This order, and the last, are placed in Engler u. Prantl. near 
XXXII—OLACACE.] 
(I) Perianth superior, tube adnate to ovary, not produced above it; often root 
parasites :— 
(i) Leaves opposite :— ... oan Be =e oe .. deccii—Santalum. 
(ii) Leaves alternate :— 
(1) Unarmed ; branchlets a inches long) sharply 8-sided ; male flowers 
in pedunculate clusters:— ... --  decciii—Osyris. 
(2) Thorny ; leaves coriaceous ; male flow: ers in 1 catkin- like spikes :— 
decciv—Scleropyrum. 
(IT) Perianth inferj or, lobes divided to the broad base or dilated summit of 
the peduncle ; flowers minute polygamous, in little spikes er clusters, each sub- 
tended by a scale-like bract which is often very deciduous ; leaves minute and 
scale-like, alternate, deciduous, or O :— oO a a6 ... dcccyv—Exocarpus. 
CII—EUPHORBIACEA— 
[Anatomical features.—In species of Croton, Macaranga, Mallotus, and Homonoia, the 
underside of the leaves is densely clothed with minute orbicular, often shining, scales, 
consisting of radially arranged cells or rows of cells. In these cases (as well as in 
Elwaqnus, Heritiera, and other trees}, the closer covering of these minute scales doubt- 
less affects the transpiration of the leaves as well as the interchange of air. This 
action is probably analogous to that of a dense felt of stellate cr other hairs. No sharp 
limit exists between these scales and the flat stellate hairs which clothe the underside 
of leaves in some of the genera mentioned, and in other genera of this order. Many 
species have a copiousacrid milky juice, and some, e.g., Manihot, Hevea, some of the 
best caoutchouc. | 
[ Botanical note.—Baillon and others separate Buaws and Sarcocscca and Engler u. 
Prantl,-these two and afew other genera, from this order to form a separate order 
—-BUXACEAi—. All Indian genera here described belong to the division of Platulobeae 
(broad cotyledons), the genera with the narrow cotyledons (Stenolobeae) are limited to 
Australia and South America. Lindley, quoting Jussieu, Adolphe Brongniart, and 
Auguste de St. Hilaire, considers that the order should be placed in the proximity of 
XIX—-MALVACEZ to which it has special affinity, though it also has affinity with V— 
MENISPERMACE) and XXXVI--RHAMNACEA. The order probably wants split- 
ting up. | ’ 
(1) Flowers united in heads resembling of a single flower, consisting of an involucre 
enclosing several flowers without a perianth, the central one ‘of which isa female con- 
sisting of a pedicelled pistil, with several males each consisting of a pedicelled stamen ; 
plants with white milky juice. 
(i) Involucre calyx like; shrubs, often leafless, or with caducous leaves. 
dcecvi—Euphorbia, 
(ii) Involucre 5-lobed, 5-glandular, campanulate, seated on a plano-convex 
cupule ; leaves fleshy, purple-veined when young . ... deccvii—Synadenium, 
(iii) Involuere slipper-like, red ; leaves fleshy, stem-clasping : —_— 
deceviii— Pedilanthus. 
(II) Flowers not united in heads, each flower witha perianth ; 7vules 2 in each 
cell, as a rule collateral (in a few cases superposed, one pendulous from the apex, the 
other from half way up the axis) ; inflorescence mostly axillary or lateral; petals O or 
minute :— 
(i) Leaves 8-foliate, alternate ; flowers panicled, dicecious :— 
deecxxiii—Bischofia. 
: (ii) Leaves undivided, whorled ; flowers panicled, dicecious :— 
decexxii— Mischodon. 
(iii) Leaves undivided, opposite ; flowers in short spikes, moncecious :— : 
decex—Buxus 
