Standardized Common
Name: Tylophora asthmatica
Family: Asclepiadaceae
Taxonomy: Tylophora
includes about 50 species of the Old World tropics, of which 21, including T.
indica, are found in India. The best known of several synonyms is T.
asthmatica (L. f.) Wight & Arn., which provides the Standardized Common
Name according to Herbs of Commerce. However, where botanical
nomenclature is concerned the name T. indica has priority over T.
asthmatica. Three varieties are recognized, based mostly on the pubescence
of the vegetative and reproductive parts. The two common and well-known
varieties are var. indica (stem, leaves and inflorescences all
pubescent) and var. glabra (Decne.) Huber (all parts glabrous). A third,
var. intermedia Rahman & Wilcock (some parts hairy, but leaf
undersides and corolla lobes glabrous) is apparently rare and poorly known, and
its status may be doubtful.
Description: Vine; stems twining
or creeping, <3 mm in diameter, pubescent or glabrous. Leaves opposite,
petiolate, separated by internodes 2–15 cm long; blade usually 1.5–9.5 cm long,
ovate-oblong to elliptic-oblong; apex mucronulate to apiculate or acute; base
rounded, often somewhat oblique, or shallowly cordate; margins entire, ciliate.
Inflorescences axillary, umbellate. Calyx 5-lobed, the lobes narrowly
lanceolate, 2.5–3.5 mm long, pubescent; corolla orangish to yellowish with
violet spots or interior, rotate, 5-lobed, ca. 9 mm in diameter, the inner surface
pubescent; stamens fused into staminal column, with pollen borne in pollinia;
corona fused below to staminal column, with 5 lobes and 5 free appendages 1.5–2
mm long, tipped with narrow fleshy points; carpels 2. Fruit a pair of
follicles, 5–7 cm long by about 1 cm in diameter, narrowly lanceolate; seeds
numerous, milkweed-like, small, brown, with tuft of white hair ca. 3 cm long.
Parts
in commerce:
Leaves
Identification:
- Blade
(1.5–)2.5–7(–12.5) cm long
- Elliptic-oblong
to ovate-oblong
- Petiole 3–20 mm
long; when long, usually less than one-fourth (at the extreme, one-third)
of blade length
- Apex usually
rounded with a mucron, sometimes acuminate or acute
- Base weakly
cordate or rounded and often asymmetrical
- Margins entire
- Pubescence
variable: glabrous in var. glabra, otherwise pubescent at least on
lower surface, petiole and margins; sometimes also on upper surface along
veins or sparsely throughout
- Hairs, where
present, all very short, soft, straight, white
- Venation
pinnate; secondary veins weak but frequently darker colored in dried
material
- Secondary veins
3–8 pairs, irregularly alternate, diverging from midrib at
30–45(–60)-degree angle, splitting and the main branch curving forward to
anastomose with the backward-curving branch of the next secondary vein
well inside the margin
- Tertiary veins
irregularly branching, weak or concealed by hair in densely pubescent
individuals, often few in number, some arising from midrib between
secondary veins; higher-order veins very inconspicuous
- Pale green or
tan-green to moderately dark on upper surface
- Odor and taste
usually weak (sometimes reported to be nauseating)
Some
pharmacognostic references indicate that the leaves of T. indica may
exceed 12 cm in length. However, the latest revision of the Indian species of Tylophora
states that the leaves do not exceed 10 cm. Some of the material described by
older sources may have been of related species, although it is possible that
variation within T. indica is greater than recognized. For example, the
lowermost leaves of a vine, which might be larger than the apical leaves, are
rarely included in the herbarium material that is used to produce most
revisions. Leaves over 10 cm in length should receive extra scrutiny; they
should otherwise resemble the smaller leaves and have no unexpected features.
References:
Bentley R, Trimen H. Medicinal Plants. Vol. 3. Delhi: Periodical Expert Book Agency
and International Book Distributors; 1880 reprinted 1981:No. 177.
Greenish HG. Materia Medica. Jodhpur: Scientific Publishers (India); 1920
reprinted 1999:60.
Jagtap AP, Singh NP. Fascicles of Flora of India:
Fascicle 24. Calcutta: Botanical Survey of India; 1999.