Plant puzzles

Sunday, 01 May 2016

The correct name of my first Salvia - Indigo Spires - was a mystery for quite a while; I bought it as Salvia regia

Sometimes I think there is nothing I like more than a plant puzzle - a mystery plant that I simply have no knowledge about. Of course, when I first started gardening, more than 35 years ago, all plants were a mystery to me: a vast, green enigma. I used to spend hours flicking through my original gardening book, What Flower Is That? by Stirling Macoboy, trying to memorise names and blooms: it was all a like a foreign language to me. In those days, I couldn't see the point of learning botanical names, and loved the common names better. It's only been through a long, slow learning curve that I have gained a modicum of understanding of some members of the plant kingdom, and why it can be good to learn their proper names. But I only have to open the pages of a plant encyclopaedia or visit the garden of a specialist in a particular group of plants to realise how miniscule my knowledge actually is! It's fascinating to see a plant that is totally unfamiliar somewhere and ponder, 'What on earth is THAT?'

This plant, photographed at the Royal Botanic Garden, Sydney, is still a mystery to me; there was no label on it

Even in my own garden today, I have a melange of unidentified plants, usually ones I have been given as cuttings by kind friends, or bought as unlabelled specimens from a church fete. It's amazing, however, that eventually the names of these plants are revealed, usually in the most random and serendipitous of ways. I love finding out things this way, and get a thrill every time I finally track down the identity of one of my mystery plants. It's like another piece of a gigantic and intricate puzzle falling into place. I might see the plant at a nursery or plant fair, with its name on a neatly written label; I might spot it in someone's garden and the owner will happily share the botanical name; or a knowledgeable visitor to my garden will casually tell me the name of something that has mystified me for years (sometimes pointing out that my prize plant is in fact a weed!).

Odontonema, species name unclear

My very first plants came from my parents' Blue Mountains garden, which wasn't really a typical cool climate garden: my mother experimented with a number of plants that were marginal in that zone, yet which survived because of a tree canopy that protected them from the effects of winter frosts. Some of her favourites have become mine, including bromeliads, Plectranthus and a selection of Acanthaceae plants, which many years later became a focus of my own plant collecting. Mum never bothered much about finding botanical names of plants she was given from friends (though she was very diligent about keeping the labels of ones she had bought from nurseries). One of her Acanthaceae stalwarts was the red-spired plant that she referred to as 'red justicia', an incredibly tough and floriferous shrub that blooms in late summer and early autumn. It took me a number of years to establish this was in fact an Odontonema, but I am still quite uncertain as to the correct species name for the plant, so it remains one of my plant puzzles, which I hope one day to solve.

Rhinacanthus beesianus, previously only known as Pseuderanthemum species

Another Acanthaceae plant which was long a mystery to me was the gorgeous Rhinacanthus beesianus, given to me by a friend, who noted that it was identified in the Sydney Botanic Garden simply as 'Pseuderanthemum species', grown from seed found in the Yunnan Province in China in 1996. This is a most unusual shrub, with flowers in autumn that are shaped like pristine white scalloped shells. I searched for a number of years to find the right name of the plant, without success. One day when strolling through the Mt Tomah Botanic Garden chatting to a friend, I idly noticed the plant with its correct name on a small plaque - if I hadn't been looking that particular way at the time I would have missed it. It sounds ridiculous but I felt as thrilled as if I had actually discovered the plant in the wild myself!

Barleria cristata

Another Acanthaceae plant (given to me by the same kind friend who gave me the Rhinacanthus) has just come into bloom in recent weeks, with lovely clear white trumpet flowers. She was recently able to provide me with its correct name - Barleria cristata - and very pleased I was to know its proper moniker. It's a small shrub about 60 cm tall, and like so many of the Acanthaceae family, it flourishes in semi-shade. I'm hoping it will prove hardy in my garden; some Acanthaceae plants succumb to cold over winter in Sydney.

Alpinia nutans

Whilst I feel I am gradually getting a handle on THAT plant family (though there are many, many more to discover), other plant groups remain a riddle to me. I have absolutely no knowledge of ferns, apart from having identified a couple that were given to me by some elderly gardeners many years ago (Cyrtomium falcatum and Asplenium bulbiferum), but I hope one day to unravel the intricacies of these lovely and useful plants, which provide such a foliage contrast to plainer leaves, and are so valuable in shaded gardens. Similarly, the world of Gesneriad plants is totally alien to me; I feel like a complete beginner when confronted with any members of this big family. The ginger family (Zingiberaceae) is also quite foreign to me; I only recently discovered that a lush, wide-leafed plant from my parents' garden, which I have had growing in a clump for more than 20 years, is Alpinia nutans, a member of this family, and that it is often called 'false cardamom', as its foliage smells so richly of that spice. I've always loved this plant for being an uncomplaining, reliable filler of difficult spots in dry shade, and it's good to finally know what to call it!

I love the thrill of the chase of finding plant names for all my mystery plants; gardening really is a never-ending process of learning. Finding the right name helps in discovering more about how to grow the plant well, because we can then research where it comes from, what sort of conditions it likes, and whether it is likely to succeed in our climate. Often the botanical name itself gives interesting clues about the history of the plant and its way of growing. Annoyingly, however, many of the botanical names keep changing! We've dedicated one of our igarden plant forums to the subject of Mystery Plants, and hope it may be helpful for readers who are trying to solve their own plant conundrums!

Reader Comments

  • By Sue T. 2566 Monday, 02 May 2016

    Glad you finally found the name for your Rhinacanthus.Knowing the scientific names for plants lets us recognise similarities we might otherwise not notice Any time I see something new and exciting in the botanic gardens there is never a label to tell me what it is. very frustrating. Sue Yes, botanical names tell us so much and are illuminating re relationships with other plants. It is frustrating when the Botanic Garden does not have a label on an unusual plant! Deirdre

  • By Sue 2074 Monday, 02 May 2016

    Interesting blog and one I can identify with as I often chase up what is the correct name of a plant, and then have difficulty in the pronunciation:-) The info I have on the "Red Justicia" is ODONTONEMA strictum (syn Thyrsacanthus, Justicia) - this is according to your old friend Stirling Macoboy. His comment: "O.strictum is the only one of 30 species you are likely to see outside the true tropics." Thanks so much, Sue. I have heard of a lilac-coloured one growing in Sydney but have yet to see it! Deirdre

  • By lillian 3951 Monday, 02 May 2016

    It is wonderful to identify one of your mysteries. It also helps to write it down!!! I keep promising myself to carry a properly organised little diary all the time. Great to solve the mystery - even better to keep a proper record of it. Love all your blogs L Thanks, Lillian. I do try to have a notebook (and camera if possible) wherever I go that I might see a new plant. I am always grateful if I do take the time to record the details of something different. Deirdre

  • By Gillian 2073 Tuesday, 03 May 2016

    I too love the thrill of discovering a new plant and a handle to hang on it! I wondered if your mystery plant is some sort of cestrum spp? There are a few obscure ones about. Thanks, Gillian. I will look into that suggestion. Deirdre

  • By Helen 7256 Tuesday, 03 May 2016

    Unravelling the mysteries is very satisfying. I have come to gardening the other way about - having studied botany before I started gardening & am fascinated with perennials. Have often known a plant by reputation before " meeting it in person". Had a wonderful time in the UK last year seeing all those cool climate perennials in the flesh. In my own garden was mystified for a few seasons by the autumn crocus with their habit of spring leaves, disappear in summer & glorious flowers in autumn. That would be fab to have that botanical knowledge. Lovely that you were able to visit the UK gardens and see those gorgeous plants. Deirdre

  • By Pam 2159 Wednesday, 04 May 2016

    Hi Deirdre, I have several "mystery" plants plants too.they are often gifts, with name unknown. Is your plant Hamelia erecta or Hamelia patens - Mexican Fire Bush? Thanks, Pam; I do not know that genus at all but it definitely seems a possibility for that mystery plant when I google pictures of it! Deirdre

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