কাউয়াঠুকরি / কাউয়াঠুকরী/ কাউয়া ঠুকরী / কাউয়া-ঠুকরী/ কাউয়া-ঠুকরি /কাউয়া ঠুকরি / কাওয়া ঠুকরি / শালুক ঘাস / মুয়া-মিয়া /lesser arrow-head / Sagittaria guyanensis

কাউয়াঠুকরি / শালুক ঘাস / মুয়া-মিয়া
Common name: Guyanese Arrowhead / lesser arrow-head
বৈজ্ঞানিক নাম: Sagittaria guyanensis
গোত্র : Alismataceae
______________________________________________________
কাউয়াঠুকরি (শালুক ঘাস/ মুয়ামিয়া) গাছটি খাল বিলে খুব দেখা যায়। কেউ কেউ আবার পানচুলির মত একেও চাদমালা বলে থাকেন। এর ফুল দুগ্ধ সাদা। ভিতরে পাপড়ির গোঁড়ার দিকে গাঢ় মেরুন এবং গোড়ায় হলদে। ফুল গন্ধ হীন। ফুল আনুমানিক ৪ সেঃমিঃ হতে ৫ সে.মিঃ আকৃতির। দেখতে খুব সুন্দর। ফল হয়, আকৃতিতে ২/৩ সেঃমিঃ। ফুল ফোটে আগস্ট হতে নভেম্বার পর্যন্ত।

•  তথ্য ও ছবি : Botany.bd / (T.B-এর পোস্ট থেকে)
• ছবির শেষে ইংরেজিতে গাছটি সম্পর্কে বিস্তারিত বর্ণনা আছে।

পুরুষ ফুল (white with a purple spot near the yellowish base),পুংফুলে পুংকেশর থাকে ৬-৯টি

উভলিঙ্গিক ফুল (পুংকেশর থাকে 6-12টি)

পাতা ও ফুল

(ফটোগ্রাফিতে দক্ষ তরুপ্রেমী তাপস বর্ধনের হাতে কাউয়াঠুকরির ফল)

Description in English

Seedlings of S. guyanensis grow rapidly in standing water. It is a lactiferous herb without stolons. The average height of the herb is 40 cm (10-80 cm). The leaves are floating and simple, the margin entire, broadly arrow-head shaped and oval in outline, and 3-12 x 2.5-11 cm. The leaf tip is obtuse-rounded, and the base is deeply cordate and sagittate with two broad diverging lobes; the veins are basal, prominent below. The petiole is usually about 15-30 cm long, septate, with air-ducts; the basal part has a broad, membranous sheath.

The hypocotyl is 0.5-3.5 mm long, glabrous, and white to green in colour. There is sheathing around the first leaf; the sheath is transparent and glabrous. The first leaf is narrowly elliptic, 8-12 x 1.3-1.5 mm, and glabrous; the midrib is distinct; the base attenuate; the margin entire; and the apex acute to rounded (Soerjani et al., 1987).

The inflorescence is a raceme; the peduncle is flaccid, 10-30 cm long, with several whorls of flowers attached to the main axis. The flowers are barely emerged above water level at the bud stage, but fully emerged when open. Flowers are usually in whorls of three, erect on short pedicels, 0.5-1 cm long. There are three bracts in each whorl; three sepals, united, broadly triangular, and keeled; and three delicate, obovate petals, with rounded tips, white with a purple spot near the yellowish base. Flowers are mainly unisexual; bisexual flowers are usually in lower whorls. The flowers often open partially at noon but close long before sunset. Flowering takes place throughout the year. The flower is staminate with 6-12 stamens (6-9 in male flowers, 9-12 in bisexual flowers); filaments are 2 mm long, glabrous to glandular, and covered with papillae. Carpels are numerous, yellow, and inserted on a convex, cup-like receptable; the styles are yellow, and 1 mm in length; the stigmas are minute and inconspicuous. Fruit is a nodding aggregate on a strongly thickened pedicel. The fruit aggregate is about 10-15 mm in diameter, and ripens under water. Fruitlets (achenes) have short stalks, are elliptic, flattened, warty, with an incised margin, echinately ribbed. The seeds are brown, 1.5 mm long; the exocarp has a blunt, broad spiny crest.