En Español

Q. Who is Mr. Smarty Plants?

A: There are those who suspect Wildflower Center volunteers are the culpable and capable culprits. Yet, others think staff members play some, albeit small, role. You can torture us with your plant questions, but we will never reveal the Green Guru's secret identity.

Help us grow by giving to the Plant Database Fund or by becoming a member

Did you know you can access the Native Plant Information Network with your web-enabled smartphone?

Share

Ask Mr. Smarty Plants

Ask Mr. Smarty Plants is a free service provided by the staff and volunteers at the Lady Bird Johnson Wildflower Center.

Search Smarty Plants
    
 
See a list of all Smarty Plants questions

Please forgive us, but Mr. Smarty Plants has been overwhelmed by a flood of mail and must take a break for awhile to catch up. We hope to be accepting new questions again soon. Thank you!

Need help with plant identification, visit the plant identification page.

 
rate this answer
1 rating

Saturday - April 09, 2005

From: Fresno, CA
Region: California
Topic: General Botany
Title: Smarty Plants on spines
Answered by: Nan Hampton

QUESTION:

What do you call part of a plant that is needle-like or has spikes or bristles?

ANSWER:

The sharp projections found on plants, which are used mainly as a defense against animals, have several different names and origins. Botanists identify three major kinds: thorns, spines, and prickles. The thorns are modified stems ending in a short point. They originate from axillary buds at nodes (where leaves or branches arise). Texas hawthorn (Crataegus texana) is an example of a plant with thorns. Spines are modified leaves or parts of leaves. The American holly (Ilex opaca) and agarita (Mahonia trifoliolata) have leaves modified with sharp projections from the edges. Cactus spines are modified sharpened petioles (leaf stalks) without the leaf blades. Prickles are woody outgrowths of the epidermal tissue or bark and occur in irregular patterns between the nodes. Prickles are often recurved and can serve as support for vines as well as a defense mechanism. Prickly ash, or Tickle-tongue (Zanthoxylum hirsutum), in the Family Rutaceae, and raspberries and other members of the rose family (Family Rosaceae) have prickles.

Additionally, many seeds and seed cases have hooks and barbs that enable them to attach to clothing or animal fur and help to disperse the seeds. Two examples are the Canada cockleburr (Xanthium strumarium) and the devil's claw (Proboscidea louisianica).

You can read more about "Prickles, thorns, spines and their relations" on the National Council for the Conservation of Plants and Gardens web page.

 

From the Image Gallery


Texas hawthorn
Crataegus texana

Agarita
Mahonia trifoliolata

Texas hercules' club
Zanthoxylum hirsutum

Louisiana devil's-claw
Proboscidea louisianica

American holly
Ilex opaca

Agarita
Mahonia trifoliolata

Texas prickly pear
Opuntia engelmannii var. lindheimeri

Texas hercules' club
Zanthoxylum hirsutum

Grayleaf red raspberry
Rubus idaeus ssp. strigosus

Canada cockleburr
Xanthium strumarium var. canadense

More General Botany Questions

Southern Live Oak Authority for Jackson MS
June 23, 2016 - Who are the foremost authorities on Southern Live Oaks? May need expert testimony to oppose cutting of 50 year-old live oaks in boulevard of Riverside Drive in Jackson, MS
view the full question and answer

Black Walnut tree in LA
March 12, 2012 - I was just given a black walnut tree and am trying to determine where to place it. I’ve read on your site that “Certain plants will not grow under Black Walnut trees because of the juglones that the ...
view the full question and answer

Plants killed by frost
October 31, 2007 - In a frost why do flowers etc. die where grass will not die?
view the full question and answer

Native vs Non-native Insect Host Plants
March 14, 2013 - My understanding of a host plant is that it is a plant that an insect will lay its eggs on. Is this correct? If this is so then can a cultivar be a host plant for the same insect? I have read Mr. Doug...
view the full question and answer

Which one is huajillo and which one is guajillo?
November 19, 2013 - Recently I attended a field trip to the Leonard Garden at the Kleberg Institute in Kingsville. I took a picture of a tree that was referred to as Tenaza or huajillo. Later I took another photo of a ...
view the full question and answer

Support the Wildflower Center by Donating Online or Becoming a Member today.
E-NEWSLETTER | BECOME A MEMBER | DONATE NOW | MEDIA | JOBS | SITEMAP | STAFF INTRANET
© 2016 Lady Bird Johnson Wildflower Center