Megistostigma burmanicum

Megistostigma burmanicum (Kurz) Airy Shaw, Kew Bull. 23: 119 1969. (Syn: Tragia burmanica Kurz); 
 
 

 

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Id of stinging climber from Arunachal Pradesh: Attachments (9 + 2). 9 posts by 5 authors.

Pl help me identifying this stinging herb from Arunachal Pradesh.
Date/Time- June, 2009
Location- Place, Altitude, GPS- Khaari, East kameng District, Arunachal Pradesh (ca 500m)
Habitat- Garden/ Urban/ Wild/ Type- Wild
Plant Habit- Tree/ Shrub/ Climber/ Herb- Climber
Height/Length- ca 3 m high
Other Information like Fragrance, Pollinator, Uses etc.- This plant causes severe itching if touched to skin.

Any possibilities to be a Tragia sp.?

And this is some Euphorbiaceae member.

Thanks a lot Muthu ji for the clue!
A few days back … had also suggested me to look for Tragia.
Today I checked it on the New York Botanical Garden Virtual Herbarium
(http://sweetgum.nybg.org/vh/specimen.php?irn=89808), in Illustrated flora of Vietnam and in Flora of China.
I think this plant is Pachystylidium hirsutum (Blume) Pax & K. Hoffmann (Syn.: Tragia irritans, T. hirsuta).
Distribution: IndoChina, Peninsular India, Thailand, Vietnam, Combodia, Philippines, Java and Laos.
Other comments are solicited.

I also search this plant in E flora of china it shows same result.
Here are some details from Flora of China
Pachystylidium hirsutum (Blume) Pax & K. Hoffmann in Engler, Pflanzenr. 68(IV. 147. IX-XI): 108. 1919.
Tragia hirsuta Blume, Bijdr. 630. 1826; T. delpyana Gagnepain.
Subshrubs, twining, ca. 3 m tall, hirsute, with stinging hairs. Stems slender, woody. Stipules triangular, 1.5-4 mm; petiole 0.8-4 cm; leaf blade ovate or elliptic, 5-13 × 3-10 cm, thickly papery, sparsely hirsute to glabrescent with midrib mostly hirsute, base shallowly to moderately cordate, margin serrate, apex abruptly acuminate; lateral veins 3 or 5 pairs. Inflorescence 1-8 cm, hirsute and puberulent, peduncle 0.4-3 cm, with 1-5 female flowers and many male flowers; bracts narrowly lanceolate, 1-2.2 mm. Male flowers: pedicel 1.5-2.3
mm; calyx lobes ovate, ca. 1 mm; anther locules ca. 0.5 mm. Female flowers: pedicel ca. 1 mm; sepals lanceolate, elliptic, or ovate, 1.5-2.5 mm, sparsely pubescent or glabrescent; ovary densely hirsute;
styles connate into a stout-cylindric or ellipsoid column, free style tips recurved. Fruiting pedicel 3-5 mm; fruiting sepals persistent, reflexed; capsule ca. 1 cm in diam., drying dark brown, sparsely setose. Seeds subglobose, 3-5.5 mm in diam., mottled pale brown and dark reddish brown.

Fl. and fr. Aug.
Seasonally dry open scrub.
Yunnan (“Lam Ko District”) [Cambodia, India, Indonesia, Laos, Philippines, Thailand, Vietnam].

Yes …, i think you got the correct id. We collected this species from Khurda / Khordha district in Orissa and got it identified by using Flora of Orissa by Saxena & Brahmam.

It seems that the plant is rarely distributed in Orissa (http://
www.vasundharaorissa.org/Research%20Reports/Threat_Status%20of%20Plants%20of%20Conservation.pdf).
In Arunachal too, I’ve seen the plant only in this particular area.
Sending another link to confirm the identity from the flora of Thailand.
http://www.nationaalherbarium.nl/thaieuph/ThPspecies/ThPachystylidiumT.htm

You are right, … It is an uncommon species and interestingly Pachystylidium is a monotypic genus. Did you check the recent revision of the family? and what is the distribution status in India? As per the first link provided by you, it is seemingly reported from OR, MP, CG, BI only. Is your collection a new distributional record to NE India?
And i could not find any picture of this species in the net, except now in efloraofindia database. So perhaps u r first to share pictures to the world. Congrats!
Attaching mine (not a good pic though).

Pachystylidium hirsutum.

I think the identification is correct. However, Pachystylidium hirsutum has not been recorded from Eastern Himalayas. So far it is known from Odisha, Andhra Pradesh and Madhya Pradesh. Hence it may be a new record for Arunachal Pradesh. But survey of literature is needed to find out if anybody recorded it from Arunachal Pradesh. If … can locate the plant again in its natural habitat, he may kindly prepare herbarium specimens and donate to BSI herbaria at Itanagar, Shillong and Central National Herbarium at Howrah, it would be very useful.

I am extremely sorry. It is Megistostigma burmanicum, a new record for Arunachal Pradesh. 

Distribution known so far: India (Nagaland), Myanmar, China, Thailand and Malaysia