Monday, August 26, 2013

Err dear...I think there's going to be a naked lady dancing on the balcony!

Hah! The title caught your attention, didn't it? Well, the 'naked lady' in question here is Lycoris sanguinea; various species of Lycoris are commonly known as naked lady, surprise lily, hurricane lily or magic lily. This bulb is from Diana of KBB. Having just planted it, I was expecting it to put forth leaves since Lycoris are known to dislike disturbance and will sulk and not flower.

However, there are also some people who reported that the bulbs do flower in the same year they are put in. So perhaps this was a lucky bulb. Another amazing thing I learned from this plant is the fast rate of growth of the flower stalk. No wonder they are also called surprise lilies. On the afternoon of 24th, a red-tipped white spear could be seen. The next day on the 25th, the whitish-red spear begins to appear like a 'pregnant lady' trying to conceal the buds inside.
1pm 24th Aug: The tip showing above the soil - the reddish top is what got me wondering if it is a leaf tip or something else.
4pm 25th Aug: Looks like there's something inside the two 'flaps'. The flaps appears to be the involucral sheath that isn't covering the buds properly. The tip had elongated 1cm in a day!

Around 8.10am today (the 26th - not even a full day from the 25th), the 'pole' for the naked lady to dance on can be seen i.e. the base where the umbel joins to the stalk (with the junction of the involucral sheath).
8am 26th Aug: Not even in one day, the stalk grew another 0.75 cm! The buds can be clearly seen peeking from the sheath and the junction of the sheath to the flower stalk can be seen (just above soil level).

I cannot take credit for the flower buds, for the bud primordia would have developed at the end of the growing season and through the resting period at Diana's place. So here's to a naked lady dancing on the balcony. In the meanwhile, a little joke whilst we wait for 'her' to complete her magical appearance and strip-tease act on the balcony:

Q: What should I do with the naked lady in the garden?
A: For goodness sake, put some clothes on her and get her in before the neighbour sees her!

Update on the afternoon of 27th Aug:
The buds peeking from the sheath on the 27th of Aug. The stalk had grown quite a bit (compared to previous picture) with the sheath junction almost 2 cm from soil level when it was just slightly above soil level the previous day.
Kudup bunga dah mula 'selak kain' dalam proses membuat persembahan Naked Lady. Kawan-kawan KBB lain yang tanam Lycoris sanguinea berbunga juga ke? Takut sangat tangkai bunga ni patah akibat angin kencang.

Monday, August 12, 2013

Starry starry Night... Summer Triangle, Meteor Showers and Holidays

Salam Aidilfitri to my friends who are celebrating the Eid Festival. This week in August has so many things going on that I forgot to wish my friends a Happy Eid. And I am still awaiting for your invitation to open houses and makan etc., hehehe (pulling a cute Puss in Boots look with a sign across my forehead saying 'thick-skinned'). 

Anyhow, with a little bit of luck, we might be able to catch 'free fireworks' from the sky, i.e. the Perseid showers. This meteor shower are the result of debris from the comet Swift-Tuttle entering our atmosphere and burning up. The night of 12th August to the morning of 13th August has been said to be the best nights to observe the celestial display, provided that clouds do not obscure the view.

The radiant (apparent origin) of this shower is in the constellation Perseus. This means that the streaks of light will appear to originate from an area of the constellation Perseus. Hence the name Perseid showers as meteor showers are always names after the constellation where the radiant lies in. From Kuala Lumpur, due to our equatorial position, the constellation Perseus does not rise above horizon until past 1am in the morning (i.e. 1am on 13th Aug) . Hence viewing would be better in the wee hours of the morning and up till dawn. Also the waxing crescent moon sets after 9.30pm, thus giving us a dark sky that is more conducive for viewing.
The Perseid radiant is just 15o above the horizon at 2am in Malaysia (made with Stellarium software). Notice that the direction that Perseus rises from is north-easterly. 15o is approximately the distance between your pinkie and index finger stretched out when held to the sky; so if there are hills (like viewing from KL towards north-east), you still won't be able to see the radiant at 2am unless you are at Genting Highlands!

If you cannot see the radiant point it does not mean that you cannot see the shower. Rather, you will only see very much less trails than the average count. It is just like looking at a fireworks display that is blocked by a row of trees, you will only see the fire trails that travel higher that the treeline. If you want to locate the radiant, you can do so following the diagram below, and only after 2am +8GMT (unless you can see 'through' the horizon and Earth).
The Perseid radiant at 4.15am on 13th Aug 2013 as viewed from KL. If you want to look for the radiant, you can either find the Seven Sisters (Pleiades) aka Subaru and follow to the leg of Perseus up to his face (count up 7 stars), and right in front of the face, and at the foot of Cassiopeia, would be the radiant. If not, the W-shaped Cassiopeia is easier to find. Just follow through the zig-zag with another step and you would've have arrived at the radiant.

Besides the shower, one can also observe the Summer Triangle, made up of the stars Altair, Vega and Deneb. These are the stars in the constellation Aquila, Lyra and Cygnus respectively, which in Chinese mythology represents the Cowherd, the Weaver Girl and their bridge of magpies (here's an article on the Cowherd and the Weaver Girl I wrote last year). It so happens that 13th August 2013 is the 7th day of the 7th month of the Lunisolar calendar, the Qixi Festival. Thankfully the Summer Triangle rises very much earlier in the night, and the best time to view it spans through a duration of several months so one does not have to stay up late or wake up early to see it nor risk missing it due to cloud cover or poor viewing conditions.
The Summer Triangle of Vega, Altair and Deneb. Stellarium image for 8pm Malaysian time as viewed from KL.

So here's to the month of August, a month of celebrations with so many festivals and celebrations, from Eid, National Days (Singapore - 9th, Malaysia - 31st, Indonesia Independence - 17th), Qixi, Hungry Ghost and most importantly to holidays.

Saturday, August 10, 2013

Growing My Own Sweet Potato Leaves

Sweet potato leaves is an underrated vegetable, and indeed there are sound reasons for that. Usually used as animal feed or composted at the end of the season when the much prized tubers are harvested, the leaves do have some nutritional value to humans. In Asian countries, despite being eaten (whether blanched and added to salads, in stews or stir-fried) sweet potato leaves still isn’t a very popular vegetable due to its associated with animal feed or famine food; therefore it is usually not served when other ‘better’ vegetables are available.
Sweet potato leaves - animal fodder or nutritious vegetable?

Those that do eat them can sometimes find that the leaves are chewy or stringy, and rather difficult to macerate down even with repeated mastication. Indeed, I have on occasions felt like a goat chewing on stir-fried sweet potato leaves. Also, many whom are newly introduced to this greens end up not liking the taste or the texture of sweet potato greens as it can be quite mucilaginous, and is probably a bit ‘greenish’ in taste.

Overall, the palatability of the sweet potato leaves voice down to the selection of the cultivar, the age of the leaves and finally the method of cooking them. Thus picking the right type, at the right time and with the right cooking method can make goat chow into a delicious vegetable.

Technically all sweet potato leaves are edible. Edible, but not be palatable. For example, the decorative sweet potato cultivars have been reported to be ‘chemical’ tasting by some. Some cultivars are very stringy and fibrous, even the young leaves require some effort to masticate. I prefer the Japanese-type sweet potato leaves, i.e. the leaves of the Satsumaimo type (red/purple skin with white/pale yellow flesh).
All purple sweet potato - rich in anthocyanins. They are marketed as Royal Diamond, but as far as I am aware of, it is a market branding name, like Grace Cup, and not a cultivar name.
Orange-fleshed sweet potato with rose/orange skin - full of carotenoids. These are from the supermarket and are labeled as imported from Australia. They are actually baby tubers (not quite mature ones) and the runt of the lot. I guess the good ones they keep for themselves or for some other food industry that require uniform tubers for processing.

The leaves of these types do not feel like chewing on a luffa sponge, and indeed the tubers themselves have minimal strings. Even large leaves on the lower section of the vines are still palatable. On the other hand, the orange-fleshed variety like Beauregard tends to be more fibrous, thus picking only the tender younger leaves might be advisable. 

The main reason for eating sweet potato leaves lies in its nutritional value, especially its lutein content, and this can vary from one cultivar of sweet potato to another. Lutein is a carotenoid that can help delay blindness-related macular degeneration. Leaves of sweet potato are a rich source of lutein. Khachatryan et al. (2003) identified sweet potato leaves as second in lutein content after marigold flowers, and is the number one among edible vegetables.

Kale has been known as a dark leafy vegetable with the highest amount of lutein at 0.38mg/g, but Menelaou et al. (2006) also showed that ‘Bienvillle’ and ‘Beauregard’ variety sweet potato leaves had 0.54mg/g and 0.51mg/g lutein respectively, which are very much higher than kale. In fact the lowest lutein containing cultivar that they tested had equivalent amount of lutein as kale. In this case, eating Beauregard or Bienville leaves can provide you with significant amounts of supplementary lutein.
The raw tubers cut open, revealing the vividly coloured flesh.

One note of caution, leaves of sweet potato does contain oxalates/oxalic acid. Just like amaranth leaves, the iron is less available for sorption due to the formation of insoluble oxalates. Oxalate-containing foods are also a no-no for people with renal issues.

According to Tsai et al. (2005), sweet potato leaves contain 48.6mg/100g oxalate. Amaranth (bayam -筧菜) has significantly higher oxalate content (280.62mg/100g), followed by Basella alba ‘Rubra’ or Malabar spinach (141.21mg/100g) and Amaranth tricolour - 紅筧菜 (131.4mg/100g). Even fresh starfruit has slightly lower oxalate content (263.34mg/100g) when compared to Amaranth. To reduce the amount of oxalates, the leaves can be blanched first for at least one minute, and the blanching water thrown away. 

So how do you know which cultivar of sweet potato you are eating? The Japanese type leaves are usually sold as ‘Tender / Stringless” sweet potato shoots. You can also buy Japanese sweet potato (red skin-white/pale yellow flesh) and soak it to get slips for planting.

To get Beauregard sweet potato leaves, you can easily grow a Beauregard sweet potato yourself. Okay, how do I know if it is a Beauregard sweet potato? In Malaysia it is really easy - look for orange/pale rose-skinned with golden/orange fleshed sweet potato imported from Australia. This is because the bulk of Australian sweet potato comes from the Beauregard variety!
The all-purple ones turn a deep purple when cooked, and is a little on the dry side. The orange one (imported from Australia - Beauregard?) is moist and not flaky.

The older Beerwah Gold variety, which also have similar flesh colour, has been superseded by Beauregard, Another orange type possible is Hernandez, which has distinctly darker orange flesh and deeper orange/red skin. Nevetheless, the Beauregard variety is the one that is widely marketed as it is easily peeled with smooth skin and uniformly shaped tubers.

The Beauregard variety is also a fast tuber producing variety (90-100 days), thus you won’t have to wait long before you get the tubers ready for eating. A bit of sweet potato trivia – O’Henry, a white fleshed variety, is actually a mutant of the golden Beauregard.

I have an all-purple sweet potato here that I want to test the texture of its leaves. It is commonly sold under the market brand Royal Diamond, but is probably just the All Purple Sweet Potato, which is a Japanese type sweet potato; less moist flesh when cooked and has a more powdery texture, but still reasonably sweet.

The Japanese-type sweet potatoes are less stringy, with powdery flesh and taste like chestnuts with varying degrees of sweetness. This all-purple variety is different from the local ‘purple’ variety that has creamy white skin and white-streaked purple flesh, which is similar to the Okinawan Purple.
This little all-purple sweet potato had sprouted in April, and remained so with little stubs as shoots until the end of July when I decided to soak it in water.
One week after soaking the sprouted tuber - the roots take off like crazy, followed by the leaves. I love the red-veined leaves that pop up.
One and a half weeks later, the slips were pulled off. 

I left one small tuber lying around and it sprouted. After some time remaining the way it was (like months) the thought of let’s try and see if the leaves are okay came across my mind, did I finally decided to soak the sprouted tuber. Within a one and a half week’s time, the slips were long enough and I planted them almost horizontally, since I want to maximise shoot production.
There were a lot of roots around base of each slip, and the bases of these roots are red in colour. The tuber had turned a lighter plum red colour after sprouting.
The shoots perk up after one hour of planting into soil, despite it being a hot afternoon when this was done. Bekas kecil, so tak ada harapan nak dapat ubi.

So hopefully the leaves of this type would be reasonably palatable, as the thought of possibly getting purple tubers at the end of the growing season is a plus point should the leaves taste good and most importantly, are not stringy and tough. I am not hopeful though, as Diana has mentioned that the Murasaki (purple) type are poorer producers of tubers.