KEY TO SUB-CLASSES, ORDERS AND GENERA. 167 
LXXV—ASCLEPIDACE Ai—cont. 
cymes (rarely solitary); corona annular or cupular, adnate to 
column, 5—10-lobed with 5 ligulate processes within :— 
dexli-—Ceropegia, 
(B) Flowers urceolate or disciform (much depressed urceolate) with 
contracted mouth, medium sized, purple, in small subsessile few 
flowered cymes; corona cupular, fleshy, adnate to column, 
spreading, lobulate or toothed :— Fr .. dexxxvii—-Oianthas. 
(C) Flowers rotate :— 
(a) Flowers large, purple, with long, flat, very narrow seaments, few- 
(about 3-) flowered in sessile umbels ; corona annular, adnate 
to column, with 5-rounded lobes :— ... .. dexl—Brachystelma, 
(b) flowers medium, white or pink, fleshy or waxy, in umbels; 
corolla lobes often convex, spreading or reflexed ; corona large 
stellate:— ... we oe oa Sed ... Qexxxviii—Hoya. 
(c) Flowers small or minute (4 inch diameter or less) :— 
(x) Flowers minute in axillary cymes ; corona of 5 erect scales 
adnate to the colamn :— e mae e- dcxx—Genianthus. 
(8) Flowers small, greenish or purplish, in umbelliform cymes ; 
corona white, cupular, toothed or crenate :— 
z acexxvii—Cynanchum. 
(y) Flowers small, purple, in subsessile umbelliform cymes ; 
corona large, stellate :— as ... dexxxvii—Heterostemma. 
(3) Flowers yellowish, downy, in crowded axillary umbelliform 
cyimes; corona double, corolline of 5 scales between the 
corolla lobes, staminal of a raised undnlate wing at the base 
of the anthers:— __... ig ue .. dcexxxix—Leptadenia, 
LXXVI--LOGANIACE 4. 
[Anatomical features.—Two gyoups may be distiaguished in this order: Buddleia 
and allied (non-Indian) genera have collateral vascular bundles, and the structure 
of the wood is normal. The other genera have bicollateral bundles, «nd consequently 
phloeum is found on the outside of the pith and (in most species of Strychnos) in 
the wood, on a transverse section as islands of softer texture. | 
(I) Ovules in each cell numerous :— 
(i) Corolia imbricate ; flowers in spikes, mostly panicled: fruit a 2-valved 
capsule :—- aoe wee as tae wa ane a dexliii—Buddleia, 
(ii) Corolla contorted; flowers in cymes or corymbs; fruit a berry, 
jJ—2-celled with many seeds in a fleshy pulp :— .. dexliv—Fagrea, 
(iii) Corolla valvate ; flowers in lateral or terminal cymes; fruit a berry 
J—2-celled with many seeds in a fleshy pulp :— ... dexlv—Strychnos, 
(11) Ovule 1 (rarely 2) in each cell; corolla tube short ; anthers large, exserted ; 
cymes axillary :-— “nr ! pe as dexlvi—Gardneria. 
LXXVII—POLEMONIACE A— 
(1) Capsule 3-valved ; seeds winged :— 
(i) Flowers large in terminal corymbs; calyx tubular 5—cleft; corolla 
funnel-shaped, lobes obovate spreading ; stamens 5, at base of tube, more or less 
exserted ; leaves simple :— = Are of 5 ie cedxlvii—Cantna. 
(ii) Flowers bell-shaped, solitary ; calyx foliaceous, 5-parted, persistent ; 
stamens declinate; leaves compound, terminating in a teudril at apex of 
rachis :— ae ais os aka ee aoe phe ae .. ¢cdxlviii—Cobzea. 
LXXVIII—BORAGINACEZ. 
[Anatomical featwres.—Stiff 1-celled hairs, erect or slanting, walls often thick and 
granular, base often large and rounded, are common in plarts of this order. Cordia 
and allied genera have also stellate and branched, sometimes glandular, bairs. In 
many cases the rough surface of the leaves is caused by cells of the epidermis contain- 
ing cystoliths, concretions mostly consisting of calcium carbonate. Cystoliths are 
often found in the enlarged base of hairs, and not rarely (species of Cordia) in groups 
of epidermal cells, which appear as white disks, mostly on the upper surfage of the 
leaves. | | 
