172 KEY TO SUB-CLASSES, ORDERS AND GHENHRA. 
LXXXIII—ACANTHACE Ai— 
[Anatomical features.—The leaves of most genera have in the epidermis of the 
upper surface numerous conspicuous cystolith cells, usually single and elongated, 
readily visible as raised lines (in Burlerta in pairs). Exceptions are in Thumbergia 
and Acanthus. Adhatoda vasica has cystolith cells in the tissue of the leaf, but notgn 
the epidermis. | 
I. Climbers ; calyx minute, annular or 10—15-toothed ; bracteoles large, sub- 
connate as a spathaceous epicalyx , flowers of all colours ; corolla salver-shaped, 
tube ventricose curved, lobes 5 rounded, twisted in bud; ovules 2, collateral in 
each cell; capsule beaked, seeds not supported on retinacula (upeurved subacute 
supports) :— ... 566 ALC oe “als on Ane dexcvili—-Thunbergia. 
Il. Erect shrubs (rarely, Blepharis, twiners}; calyx distinct; bracteoles 
not subconnate; seeds supported on hard retinacula; ovules 2, not collateral, 
or if more than 2 (rarely exceeding 8) superposed in 1 row, or else arranged 
alternately in each cell :— 
(i) Corolla without upper lip, lower lip large expanded 3slobed; ovules 2 
in each cell :-~ 
(1) Anterior filaments with an excurrent process; twining shrubs; 
flowers small :—__.. a Mh ihe af Re, decv—Blepharis. 
(2) Anterior filaments without excurrent process; erect shrubs; flowers 
lange). Yee Be sh nc bic okt decvi-—Acanthus, 
(ii) Corolla either with 2 lips or 5 subequal lobes :-- 
(1) Oyules 83-10 in each cell ; capsule normally 6-or more-seeded :— 
(A) Corolla subequally 5-lobed, funnel-shaped ; flowers blue, spicate, 
spikes forming terminal panicles ; stamens 4 didynamous, or 2 :— 
decii-—Stenosiphonium. 
(B) Corolla 2-lipped, large, fannel-shaped ; flowers crimson or white 
in terminal panicles or thyrses; stamens 2, sometimes with 2 
staminodes :— ses e a het dceexi-—Diotacanthus, 
(C) Corolla subequally 5-lobed, cylindric with a small oblique 
revolute limb; flowers yellow, in fascicled or panicled cymes 
emerging from large coloured bracts at the ends of the branches ; 
stamens 2exserted with 2 staminodes ; style exserted, curved and 
bifid atapex:—  ... aa sot N63 deexviili—Sanchezia. 
(2) Ovules 2 (rarely 1) in each cell; capsule normally 4-or fewer- 
seeded :—— 
(A) Corolla subequally 5-lobed (obscurely 2-lipped in Calophanes) :-— 
(a) Sepals 4, two opposite outer larger than the inner two; stamens 
2, with 2—8 staminodes; often, but not always, prickly 
shrubs :—— wee fe cee ier nie ... decvii--Barleria. 
(b) Sepals 5 :— 
(x) Stamens 4 didynamous; of if only 2 (Strobilanthes), then 
limb of corolla widely funnel-shaped :-— 
(*) Anthers 1-celled; outer calyx lobes larger than the others ; 
flowers yellow, orange, or salmon-coloured in 4-sided 
spikiest=— 7 ie. Lt ne as decviii-—Cossandra. 
(**) Anthers 2-celled ; calyx-lobes subequal; corolla tubular- 
ventricose (funnel-shaped). 
(+) Flowers solitary, often crowded on short lateral branches, 
white or pale mauve with yellow and brown markings ; 
bracteoles very large, becoming scarious, with reti- 
culated nerves ; placentas separating elastically from 
valves from base upwards :-— See ... dcec—Petalidium. 
(++) Flowers in axillary clusters or short cymes, blue with 
violet markings; bracts and bracteoles linear; placentas 
not separating elastically from valves :— 
dexcix——Calophanes, 
(ttt) Flowers capitate, in strobiliform or interrupted spikes, 
or panicled, blue, purple, yellow or white ; bracts and 
bracteoles large or small, persistent or deciduous ;—- 
dciii~-Strobilanthes, 
